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Nomadic RF transmitter architectures, september 26th
Nomadic RF transmitter architectures: principles and limits M. Villegas, A. Diet, G. Baudoin
Short course SHS01: EuWiT - EuMC
T1
Nomadic RF transmitter architectures, september 26th
Nomadic RF transmitter architectures: principles and limits Speakers and contributors Martine Villegas : Professor at EYCOM-ESIEE Paris Geneviève Baudoin : Research director at ESIEE and general chairman of EuWiT Vaclav Valenta : PhD student ESYCOM and Brno University Martha Suarez : Assistant professor at ESYCOM-ESIEE Luis Andia : PhD student with STMicroelectronics Antoine Diet : Associate Professor at Paris Sud-11 (L2S-DRE, UMR 8506) ST Ericsson team : Fabien Robert, Fabio Epifano, Philippe Cathelin, Pascal Triaire Jacques Palicot : Professor at Supélec (IETR, UMR 6164)
T2
Nomadic RF transmitter architectures, september 26th
Nomadic RF transmitter architectures: principles and limits Why this short course ? Important evolution wireless communication systems More intelligence and more reconfigurability in the transceiver More efficient spectral resource management Better transmission quality Low energy consumption Frequency band : of interest : 600MHz – 6 GHz Different approaches : multistandard, multiradio, SDR, … Different approaches for reconfigurability and low consumption T3
Nomadic RF transmitter architectures, september 26th
Nomadic RF transmitter architectures: principles and limits M. Villegas1, A. Diet2, G. Baudoin1
Welcome (M. Villegas1) Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1 – 20 mn Possible approaches analysis for Cognitive Radio J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1 – 30 mn Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1 – 30 mn (Pause)
M.
Villegas1,
High efficiency amplifiers A. Diet2, L. Andia1, F. Robert1,5 – 40 mn
Towards all-digital architectures, analysis of technical and technological locks F. Robert1,5, F. Epifano5, P. Cathelin5, P. Triaire5, G. Baudoin1, V. Valenta4,1 – 40 mn
1ESYCOM-ESIEE
T4
(EA2552), 2L2S-DRE (UMR8506), 3Supélec IETR (UMR6164), 4Brno University of Technology (DREL), 5ST-Ericsson
V.
Valenta4,1,
Spectrum analysis G. Baudoin1, R. Marsalek4, M. Villegas1 – 20 mn
Spectrum analysis
T5
1ESYCOM-ESIEE
(EA2552), 2L2S-DRE (UMR8506), 3Supélec IETR (UMR6164), 4Brno University of Technology (DREL), 5ST-Ericsson
Outline Air-interface
characteristics of mobile communication standards deployed in Europe: spectrum allocations and signal parameters Survey on spectrum utilization in Europe Goals and interests Measurement sites: Czech Republic and France Measurement equipment, measurement method and data processing Measurement results
Statistical interpretations : duty cycle, degree of the spectrum usage Spectrogram over 24 hours / 6 days
Summary
T6
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Spectrum allocation of mobile communications in Europe
2170 3600 5850
2110 3400
3300
1980
1920
2010 2025 5725
2900 5470
1900
1880
1805 2690 2700
1785 5350
2483.5 2500
1710
960
915 925 2345 2360
2400
880 5150
2305 2320
800 MHz – 6 GHz
*deployment of complementary/same wireless in other radio bands may vary, depending on the country (e.g. MMDS, UMTS 900, CDMA 450, based on full licensing or light regulatory approach) T7
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Air-interface characteristics and signal parameters 800 MHz – 6 GHz GSM900/1800
Frequency band [MHz]
Modulation Channel band [MHz] PAPR10 [dB] EVM12 ACPR13 [dBc] Pout MAX / Pout MIN [dBm] Sensitivity [dBm]
UMTS
802.11a/b/g
1900-2025 2110-2200
5150-5350 5470-5825 2412-2472
GMSK3/8PSK4
QPSK5/QAM6
OFDM7/DSSS8
0.2
3.84
16.25/20
0, 3 (EDGE11) Phase error < 5° RMS
6 12.5%@20dBm (16-QAM)
17
880-915 (UL) 925-960 (DL) 1710-1785 (UL) 1805-1880 (DL)
-60@400kHz
-33@5MHz -43@10MHz
5.6% -
WiMAX 802.16e 2300-2400, 2305-2320, 2469-2690, 3300-3400, 3400-3800
LTE Initially in the UTRA1 TDD/FDD2 bands
1.25, 5, 7, 8.75, 10, 20 29 3.16% (64-QAM) Variable, -60@double channel BW
OFDMA - QPSK, 16/64QAM 1.4, 3, 5, 10, 15, 20 22 12.5% @-40dBm Variable, -30-(-36) @3.84-18 MHz
OFDMA9
33, 30/5, 0
24/-50
20, 30/-
23/-50
23/-40
-99
-117 @ BER14=10-3
-82
-92
-
1UTRA
– UMTS Terrestrial Radio Access, 2TDD/FDD – Time Division Duplexing/Frequency Division Duplexing, 3GMSK - Gaussian Minimum Shift Keying, 48PSK – Phase Shift Keying, QPSK5 – Quadrature Phase Shift Keying, QAM6 – Quadrature Amplitude Modulation, OFDM7 – Orthogonal Frequency Division Multiplexing, DSSS8 – Direct Sequence Spread Spectrum, OFDMA9 – OFDM Access, PAPR10 – Peak to Average Power Ration, EDGE11 – Enhanced Data Rates for GSM Evolution, EVM 12 – Error Vector Magnitude, ACPR 13 – Adjacent Channel Power Ratio, BER 14 – Bit Error Ratio T8
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Survey on spectrum utilisation in Europe
Goals and interests:
Investigate the degree of the global radio spectrum utilisation in the radio band 100 MHz – 6GHz
Compare spectrum utilisation in different regions
Determine utilisation behaviours / trends of individual communication standards in specific environments
Point out on certain poorly utilised bands that could be dynamically accessed by future opportunistic devices
To prove that the radio spectrum scarcity is an artificial product of archaic public policies rather than a reality T9
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Measurement sites: Czech Republic and France Region no.1: northern suburb of Brno, Czech Republic
No.1
Radio band: 100 MHz – 3 GHz
5 km
Region no.2: eastern suburb of Paris (ESIEE Paris), France Region no.3: city of Paris, near “Place de la Nation”
No. 3 No. 2
Radio Band: 400 MHz – 6 GHz 5 km
T10
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Measurement equipment, measurement method, data processing
Energy detection principle: Log.- Periodic antennas, spectrum analyzers, PC + GPIB + Matlab Instrument Control Toolbox
• 100 MHz -3 GHz
• 400 MHz -7 GHz T11
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Measurement equipment, measurement method, data processing (cont’d)
The whole bandwidth divided into x 20 MHz sub-bands: Hz 0M 0 1
z H 6G
Bandwidth to be analyzed
-4 0 -6 0 -8 0 -1 0 0
…..
0.5
1
1 .5
2
2 .5
…………… up to 145/280 sub-bands •
3
SPAN 20 MHz
Power
(125/160 samples per one band making 160/125 kHz spacing) 0.74
0.745
0.75
0.755
0.76
0.765
0.77
0.775
20 MHz
0.78
• •
RBW 3 kHz / 55kHz 111.108x106 samples/6-days
(125/160 samples) T12
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Measurement results Following slides will depict radio spectrum utilization as follows:
-50
-100 16:30 12:30 8:30 4:30 00:30 20:30 16:30
Duty Cycle
Time
Power [dBm]
Threshold*= -97.3 dBm
1.75
1.8
1.85
•
Radio power profile (maximum power over 6 days)
•
Power samples superior to the threshold*(considered as
1.9
occupied) 1.75
1.8
1.85
1.9
1 0.5 0
• 1.75
1.8 Frequency [GHz]
1.85
Duty Cycle =
N (P > threshold) N Total
1.9
*the decision threshold has been set in most cases to 7 dB above the level of the average background noise. T13
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Power [dBm]
-40 Threshold = -94.24 dBm -60 -80 0.43
0.44
0.45
0.46
0.47 Time
0.42
0.42
0.43
0.44
0.45
0.46
0.47
0.5 0 0.41
0.42
Region
0.43 0.44 0.45 Frequency [GHz]
0.46
0.47
Utilisation in
Freq. allocation
No. of TV
400-470 MHz [%]
[MHz]
Brno
19.71
470 – 862
49
ESIEE Paris
9.83
470 – 830
45
Paris Nation
6.37
channels
Threshold = -94.37 dBm
-40 -60 -80
11:00 7:00 3:00 23:00 19:00 15:00 11:00 Duty Cycle
0.41 11:00 7:00 3:00 23:00 19:00 15:00 11:00 0.41 1
Duty Cycle
Time
Power [dBm]
410 – 860 MHz Radio Band
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.5
0.55
0.6 0.65 0.7 0.75 Frequency [GHz]
0.8
0.85
1 0.5 0
No. of “occupied”
Utilisation
Utilisation
TV channels
(Method 1)1 [%]
(Method 2)2 [%]
20
21.2
40.8
28
44.9
62.2
23
29.9
51.1
1Method 1 is based on the "thresholding method" as described in the previous slide. This method corresponds to the average duty cycle. 2Method 2 considers the whole 8MHz channel as occupied when both, the main carrier and the audio sub-carrier exceeds the threshold value (to protect analog TV). The utilization is then calculated as a ratio of occupied channels and total available channels in the band (49 and 45 in Czech Republic and France respectively).
T14
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
410 – 860 MHz Radio Band (cont’d)
ESIEE Paris
11:00 7:00 3:00 23:00 19:00 15:00 11:00
Paris Nation
Brno
TV 470 – 830 (862) MHz 11:00 7:00 3:00 23:00 19:00 15:00 11:00
11:00 7:00 3:00 23:00 19:00 15:00 11:00
Region
T15
dBm -60
-70 0.45
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85 -80
-90 0.45
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85 -100
-110 0.45
0.5
0.55
0.6 0.65 Frequency [GHz]
Utilisation in
Freq. allocation
No. of TV
400-470 MHz [%]
[MHz]
Brno
19.71
470 – 862
49
ESIEE Paris
9.83
470 – 830
45
Paris Nation
6.37
channels
0.7
No. of “occupied”
0.75
0.8
0.85
Utilisation
Utilisation
TV channels
(Method 1) [%]
(Method 2) [%]
20
21.2
40.8
28
44.9
62.2
23
29.9
51.1
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
410 – 860 MHz Radio Band (cont’d) utilisation calculation methods in the TV band Analog TV Main carrier Audio carrier CH56
CH57
CH58
CH59
Power [dBm]
CH55
DVB-T
Threshold 0.74
0.745
0.75
0.755
0.76
0.765
0.77
0.775
Frequency [GHz]
0.78
Calculation method 1 As a ratio of the number of samples superior to the threshold level to the total number of samples in a given radio band. This value corresponds to the average duty cycle.
Calculation method 2 As a ratio of the number of TV channels considered as occupied to the number of available channels. In the case of the analog TV signal, the whole 8-MHz TV channel has been considered as occupied when both, the main carrier and the audio sub-carrier exceeded the threshold.
T16
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Zoom on 410 – 470 MHz Radio Band (cont'd) CDMA 2000
ESIEE Paris
11:00 7:00 3:00 23:00 19:00 15:00 11:00
Paris Nation
Brno
UL
11:00 7:00 3:00 23:00 19:00 15:00 11:00
11:00 7:00 3:00 23:00 19:00 15:00 11:00
Region
DL
dBm
-50
-60 0.41
0.42
0.43
0.44
0.45
0.46
0.47
-70
-80
0.41
0.42
0.43
0.44
0.45
0.46
0.47
-90
-100
0.41
0.42
0.43 0.44 Frequency [GHz]
Utilisation in
Freq. allocation
400-470 MHz [%]
[MHz]
Brno
19.71
470 – 862
49
ESIEE Paris
9.83 470 – 830
45
Paris Nation T17
UL
DL
6.37
No. of TV channels
0.45
No. of “occupied”
0.46
0.47
-110
Utilisation
Utilisation
TV channels
(Method 1) [%]
(Method 2) [%]
20
21.2
40.8
28
44.9
62.2
23
29.9
51.1
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Power [dBm]
-40 Threshold = -94.28 dBm -60 -80 0.9
0.92
0.94
0.96
0.9
Time
00:00 – 8:00
0.92
0.94
0.96
0.5 0 0.88
0.9
Region
0.92 Frequency [GHz]
0.94
-40 -60 -80
1.8
1.85
1.9
1.8
1.85
1.9
1.8 1.85 Frequency [GHz]
1.9
00:00 – 8:00
1.75
1 0.5
0.96
Frequency allocation [MHz]
No.1 Brno No.2 ESIEE Paris
Threshold = -94.49 dBm
1.75
11:00 7:00 3:00 23:00 19:00 15:00 11:00 Duty Cycle
0.88 11:00 7:00 3:00 23:00 19:00 15:00 11:00 0.88 1
Duty Cycle
Time
Power [dBm]
GSM 900/1800, DECT Radio Band
0
1.75
Utilisation [%] 38.0 / 20.0
E-GSM + GSM 900: 880 – 915 (UL) / 925 – 960 (DL)
47.9 / 29.3
GSM 1800: 1710 – 1785 (UL) / 1805 – 1880 (DL) No.3 Paris Nation
T18
44.4 / 15.6
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Paris Nation
ESIEE Paris
Brno
11:00 7:00 3:00 23:00 19:00 15:00 11:00 0.88 11:00 7:00 3:00 23:00 19:00 15:00 11:00 0.88 11:00 7:00 3:00 23:00 19:00 15:00 11:00 0.88
UMTS
GSM 900 Radio Band (cont'd)
0.89
0.89
0.89
Region
0.9
0.9
0.9
0.91
0.91
0.92
0.92
0.93
0.93
0.91 0.92 0.93 Frequency [GHz]
0.94
0.94
0.95
0.95
0.94
0.95
Frequency allocation [MHz]
No.1 Brno No.2 ESIEE Paris
0.96
11:00 7:00 3:00 23:00 19:00 15:00 11:00
dBm -50
-60 -94
-93
-92
-91
11:00 7:00 3:00 23:00 19:00 15:00 11:00 0.96 -93 -92 -91 -90 -89 11:00 7:00 3:00 23:00 19:00 15:00 11:00 0.96 -94 -92 -90 Average Power [dBm]
-70
-80
-90
-100
-110
Utilisation [%] 38.0 / 20.0
E-GSM + GSM 900: 880 – 915 (UL) / 925 – 960 (DL)
47.9 / 29.3
GSM 1800: 1710 – 1785 (UL) / 1805 – 1880 (DL) No.3 Paris Nation T19
44.4 / 15.6 Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Paris Nation
ESIEE Paris
Brno
GSM 1800, DECT Radio Band (cont'd) 11:00 7:00 3:00 23:00 19:00 15:00 11:00 11:00 7:00 3:00 23:00 19:00 15:00 11:00 11:00 7:00 3:00 23:00 19:00 15:00 11:00
1.72
1.72
1.72
Region
1.74
1.74
1.74
1.76
1.76
1.76
1.78
1.78
1.78
1.8
1.8
1.82
1.82
1.8 1.82 Frequency [GHz]
1.84
1.84
1.84
1.86
1.86
1.86
1.88
1.88
1.88
Frequency allocation [MHz]
No.1 Brno No.2 ESIEE Paris
11:00 7:00 3:00 23:00 19:00 15:00 11:00 1.9 -104
dBm -50
-60 -103
-102
11:00 7:00 3:00 23:00 19:00 15:00 11:00 1.9 -100 -99 -98 -97 11:00 7:00 3:00 23:00 19:00 15:00 11:00 1.9 -99 -98 -97 Average Power [dBm]
-70
-80
-90
-100
-110
Utilisation [%] 38.0 / 20.0
E-GSM + GSM 900: 880 – 915 (UL) / 925 – 960 (DL)
47.9 / 29.3
GSM 1800: 1710 – 1785 (UL) / 1805 – 1880 (DL) No.3 Paris Nation T20
44.4 / 15.6 Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
T21
Power [dBm]
-40 Threshold = -96.12 dBm -60 -80 2.1
2.2
2.3
2.4
2.5
2
2.1
2.2
2.3
2.4
2.5
Time
2
0.5 0 1.9
2
2.1 2.2 2.3 Frequency [GHz]
2.4
2.5
Threshold = -96.12 dBm
-40 -60 -80
2.4 11:00 7:00 3:00 23:00 19:00 15:00 11:00 2.4 1
Duty Cycle
1.9 11:00 7:00 3:00 23:00 19:00 15:00 11:00 1.9 1
Duty Cycle
Time
Power [dBm]
UMTS & 2.4 GHz ISM Radio Band
2.42
2.44
2.46
2.48
2.5
2.42
2.44
2.46
2.48
2.5
2.48
2.5
0.5 0 2.4
2.42
2.44 2.46 Frequency [GHz]
Region
UMTS frequency allocation [MHz]
UMTS utilisation [%]
ISM utilisation [%]
No.1 Brno
FDD UL 1920 – 1980 ; FDD DL 2110 – 2170
2.1
0.24
No.2 ESIEE Paris
TDD 1900 – 1920, 2010 – 2025
10.8
4.47
No.3 Paris Nation
Satellite UMTS 1980 – 2010, 2170 – 2200
11.1
7.63
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Paris Nation
ESIEE Paris
Brno
UMTS & 2.4 GHz ISM Radio Band (cont'd)
T22
11:00 7:00 3:00 23:00 19:00 15:00 11:00 1.9 11:00 7:00 3:00 23:00 19:00 15:00 11:00 1.9 11:00 7:00 3:00 23:00 19:00 15:00 11:00 1.9
dBm
-85
-90 1.95
2
2.05
2.1
2.15
2.2
2.25
2.3
2.35
2.4 -95
-100 1.95
2
2.05
2.1
2.15
2.2
2.25
2.3
2.35
2.4 -105
1.95
2
2.05
2.1
2.15 2.2 Frequency [GHz]
2.25
2.3
UMTS utilisation [%]
2.35
2.4
Region
UMTS frequency allocation [MHz]
No.1 Brno
FDD UL 1920 – 1980 ; FDD DL 2110 – 2170
2.1
0.24
No.2 ESIEE Paris
TDD 1900 – 1920, 2010 – 2025
10.8
4.47
No.3 Paris Nation
Satellite UMTS 1980 – 2010, 2170 – 2200
11.1
7.63
-110
ISM utilisation [%]
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Paris Nation
ESIEE Paris
Brno
2.4 GHz ISM Radio Band (cont'd)
T23
11:00 7:00 3:00 23:00 19:00 15:00 11:00 2.4 11:00 7:00 3:00 23:00 19:00 15:00 11:00 2.4 11:00 7:00 3:00 23:00 19:00 15:00 11:00 2.4
dBm
-50
-60 2.41
2.42
2.43
2.44
2.45
2.46
2.47
2.48
2.49
2.5
-70
-80
2.41
2.42
2.43
2.44
2.45
2.46
2.47
2.48
2.49
2.5
-90
-100
2.41
2.42
2.43
2.44
2.45 2.46 Frequency [GHz]
2.47
2.48
UMTS utilisation [%]
2.49
2.5
Region
UMTS frequency allocation [MHz]
No.1 Brno
FDD UL 1920 – 1980 ; FDD DL 2110 – 2170
2.1
0.24
No.2 ESIEE Paris
TDD 1900 – 1920, 2010 – 2025
10.8
4.47
No.3 Paris Nation
Satellite UMTS 1980 – 2010, 2170 – 2200
11.1
7.63
-110
ISM utilisation [%]
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Summary: Comparison of spectrum utilisation of wireless standards in individual locations Radio band 400-470 MHz *TV Band IV&V, 470-830(862) MHz GSM 900, 880(888)-915 MHz, 925(933)-960 MHz Radio band 960-1710 MHz GSM 1800, 1710-1785 MHz, 1805-1880 MHz DECT, 1880-1900 MHz UMTS, 1900-2025 MHz, 2110-2200 MHz ISM, 2.4-2.5 GHz Radio band 2.5-3 GHz Radio band 400 MHz - 3 GHz Radio band 400 MHz - 6 GHz 0
DREL Brno ESIEE Paris Paris Nation
10 20 30 40 Spectrum Utilization [%]
50
* Summary depicted here results from measurement campaigns that were carried out during years 2008/2009 [1] V. Valenta et al., Survey on Spectrum Utilization in Europe: Measurements, Analyses and Observations, in proceedings of CrownCom 2010. [2] Mark A. McHenry et al., Chicago spectrum occupancy measurements & analysis and a long-term studies proposal, in proceedings of Workshop on Technology and Policy for Accessing Spectrum, 2006. [3] Md Habibul Islam et al., Spectrum Survey in Singapore: Occupancy Measurements and Analyses, in proceedings of CrownCom 2008. T24
Nomadic RF transmitter architectures: principles and limits Spectrum analysis V. Valenta4,1, G. Baudoin1, R. Marsalek4, M. Villegas1
Possible approaches analysis for Cognitive Radio J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1 – 30 mn
Possible approaches analysis for Cognitive Radio
T25
1ESYCOM-ESIEE
(EA2552), 2L2S-DRE (UMR8506), 3Supélec IETR (UMR6164), 4Brno University of Technology (DREL), 5ST-Ericsson
Outline •
Introduction to Cognitive Radio • •
General remarks A more general « View »
•Opportunistic •
Spectrum management – – –
•
The lower layer »
T26
Current situation Spectrum sharing The 5 phases of opportunistic communications
The sensors •
•
Communications
Hole detector
Conclusion Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Outline •
Introduction to Cognitive Radio • •
General remarks A more general « View »
•Opportunistic •
Spectrum management – – –
•
The lower layer »
T27
Current situation Spectrum sharing The 5 phases of opportunistic communications
The sensors •
•
Communications
Hole detector
Conclusion Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cognitive Radio - Introduction •
Introduced by J.Mitola in 1999
Conceptualization and « theorization » of ideas and concepts fashionable in the world of Radio communications •
• • • •
•
T28
Environmental adaptation in a broad acceptation Intelligence in the network and terminal Terminal independence towards network and operator User independence towards technique
Is based on a truly Software Radio Technology
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cognitive Radio - Introduction • A few definitions found in the literature: • ”Cognitive radio increases the awareness that computational entities in radio have their locations, users, networks, and the larger environment”. • « Cognition tasks that might be performed range in difficulty from the goal driven choice of RF band, air interface, or protocol to higher level tasks of planning, learning, and evolving new protocols. » • “this type of learning technique makes the Software Radio trainable in a broad sense instead of just re-configurable”
• Broader than the conventional view limited to the spectrum optimization T29
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
sensors
"OSI layers"
User Profile: price, subscription, personal choices (ecological radio..) Sound, image,...position, speed safety
Inter-networks and intra-networks vertical handover, standards
Access, power, modulation and coding types frequency, handover…. channel estimation antennas,consumption
Concepts found in the literature
Application and IHM
“Context-Aware”
« Cross Layer Transport, Network Adaptation Connection & Optimization »
Interoperability
Physical, medium
Surrounding Networks
Link adaptation
“Middleware” and abstraction layer T30
Wide Band Software Radio Technology
Cognitive Radio - Introduction Conventional Cognitive cycle Observation (sensors)
Knowledge Base Rules
Learning Outside world
T31
Decision Action
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cognitive Radio - Introduction Decentralized view associated with a local optimization of needs and resources versus a centralized view based on the worst case scenario needs. •
• Ex : implementation of an equalizer
independently of the channel IR T32
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Outline •
Introduction to Cognitive Radio • •
General remarks A more general « View »
•Opportunistic •
Spectrum management – – –
•
The lower layer »
T33
Current situation Spectrum sharing The 5 phases of opportunistic communications
The sensors •
•
Communications
Hole detector
Conclusion Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Spectrum management Integration: • in time • in space • in service
No available spectrum (scarce resource) T34
Spectrum management
BUT 2,4 GHz band occupancy 01/September/2004 in New York
TV band occupancy 01/September/2004 in New York
T35
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Spectrum management
Hic et nunc (Here and now) Free spectrum Spectrum sharing • Dynamic spectrum access • • • •
Vertical and Horizontal sharing Underlay sharing Overlay sharing Opportunistic communications
Q Zhao, A Swami, “A survey of Dynamic spectrum access SP and networking perspectives, ICASSP 2007 T36
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Dynamic spectrum access Command and control • Spread the signal • Power below a threshold for the primary user • Interference temperature concept • Ex UWB Secondary user
Spectrum underlay
Spectrum overlay Primary users
S. Haykin, “Cognitive radio: Brain-empowered wireless communications,”IEEE Journal on Select. Areas in Comm., Vol. 23, no. 2, pp. 201-220, Feb. 2005. T37
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Dynamic spectrum access Spectrum opportunity = White spectrum = Spectrum Hole
Open access
Spectrum overlay
Opportunistic communications
Same notion = different words in the literature Spectrum opportunities identification = great challenge
T38
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
opportunities •Holes in the wide sense •Holes in the spectrum ( spectrum opportunities) •Holes in time (slot opportunity) •Holes in code (code free in a set of code) •Holes in other dimension…..
T39
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
standard 1
standard 3 free
free
free
free
free
freq.
free
free
free
free free free
ampl.
standard 2
time
Example of holes in the spectrum
T40
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
standard 1
standard 3 free
free
free
free
free
freq.
free
free
free
free free free
ampl.
standard 2
time
The 5 phases of opportunistic communications • • • • • T41
Filtering phase Hole detection phase Characterization phase Decision making phase Insertion phase Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Filtering phase (1/5) • In one predefine band – Ex: Check if one GSM channel is free in the GSM band
• Whatever the band is – Ex: Check if a desired Bandwidth( ex 1MHz) is free in the band [1MHz - 3 GHz]
• The solution will be different T42
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Filtering phase (2/5) • FB should be able to extract channels spaced with different values. We only consider here a sequential extraction. P1 freq
P2 freq
P3 freq
T43
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Filtering phase (3/5) • FB should be able to extract channels with different bandwidths simultaneously.
T44
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Filtering phase (4/5) • FB must be able to be selective enough with a reasonable complexity as very sharp filtering expectations may be demanded, especially if the bandwidth of channels is small compared to the wideband acquired signal.
T45
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Filtering phase (5/5) • Classical FB filters does not meet these requirements. A new scheme has been recently proposed based on FRM technique [1] Ha(z) a b
w HC(z) = 1-Ha(z)
fap
fas w
fap
fas
HC (zM)
c d
Ha(zM) w
HMA(z)
HMC(z) (m-fap)/M
fp fs
e
w
(m+1-fas)/M w
fp fs T. Hentschel, “Channelization for software defined base-stations,” Annales des Telecommunications, ISSN 0003-4347, vol. 57, pp. 386-420, no. 5-6, May-June 2002. [1] R. Mahesh,A. P. Vinod, C Moy, J Palicot, “A Low Complexity Reconfigurable Filter Bank Architecture for Spectrum Sensing in Cognitive Radios”, CROWNCOM 2008, Singapour T46
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Outline •
Introduction to Cognitive Radio • •
General remarks A more general « View »
•Opportunistic •
Spectrum management – – –
•
The lower layer »
T47
Current situation Spectrum sharing The 5 phases of opportunistic communications
The sensors •
•
Communications
Hole detector
Conclusion Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Spectrum Hole detection
In each band the algorithm detection should be applied Whatever the method is • • • • T48
Energy detector Cyclostationnarity detector Covariance matrix eigenvalues detector Other…. Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
H 0 : x(t ) = b(t )
H1 : x(t ) = ∑ si (t ) + b(t ), i
Spectrum Hole detection Problem positioning y (t ) x (t )
ADC
x (n.T e )
Detector
Decision
BL
• Available band or engaged band • Hypothesis test: H 0 : x (t ) = b (t ) H 1 : x (t ) = T49
∑ s (t ) + b (t ) i i
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
H 0 : x(t ) = b(t )
H1 : x(t ) = ∑ si (t ) + b(t ), i
Spectrum Hole detection • Radiometer: (+) simple efficient (--) requires a relevant noise level estimation
• Cyclostationary: (+) far less responsive to noise level variation (--) requires a prior knowledge of the cyclic frequencies that need testing (--) responsive to Nyquist emission filtering
Multi-cycle sensor Blind sensor
T50
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Energy detector r(t)
y(t)
(• )
2
y2(t)
T
V = ∫ (•) dt 2
0
V
>
K, decides that a signal exists • Noise level threshold
* N0 is the noise spectral density
T51
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cyclostationnarity detector T=cyclic period c xx (t,τ ) = E ( x (t )x (t + τ )) = c xx (t + T, τ ) The time varying function cxx (t ,τ ) Can be developed according to the variable into the following Fourier series:
cxx (t ,τ ) = cxx (τ ) + ∑ C xx (α ,τ )ei 2πα t α ∈ψ
1 C xx (α , τ ) = lim Z →∞ Z
∫
Z /2
−Z /2
c xx (t , τ ) e − i 2 πα t dt
t
Cxx=cyclic covariance function α= cyclic frequency
• Test on a cyclic frequency (Giannakis) • Multi-cycle test1 • Blind test 1Ghozzi
M , Dohler M , Marx F , Palicot J, Cognitive radio: methods for the detection of free bands, Comptes Rendus Physique, Elsevier, pp, volume 7 September 2006 T52
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cyclostationnarity detector
Harmonics may be filtered by Nyquist filtrer
T53
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cyclostationnarity detector Digital television detection with the Multi-cycle detector
Blue=energy detector Black=Multi-cycle detector
T54
Cooperative Approach Covariance matrix eigenvalues detector Network cooperative sensing1
Secondary base stations {BS1, BS2, BS3, … , BSK} cooperatively sense the channel in order to identify a white space and exploit the spectrum. 1
L Cardoso, M Debbah, P Bianchi, J Najim ‘Cooperative Spectrum Sensing Using Random Matrix Theory », IEEE ISWPC 2008, May 2008, Santorini, Greece. T55
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cooperative Approach Covariance matrix eigenvalues detector The value of cooperation: random matrix approach
T56
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cooperative Approach Covariance matrix eigenvalues detector
T57
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Cooperative Approach Covariance matrix eigenvalues detector Spectrum sensing algorithm: computing the ratios
T58
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Covariance matrix eigenvalues detector
Simulations: detector performance
T59
Characterization phase • Agreement between TX and Rx of both A and B • Then the frequency band is an opportunity = other communications B
A
• To characterize this band (S/B, interference noise…) • To characterize the IR between A and B (great Challenge) T60
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
Decision phase • Many algorithms •Neural networks •Genetic algorithms •Statistical Signal Processing •Game theory •Example multi-armed bandit with UCB algorithm1
1Jouini
T61
W, Ernst D, Moy C, Palicot J, Upper confidence bound based decision making strategies and dynamic spectrum access International Communication Conference, ICC'10, Cape Town, South Africa, 26-29 May 2010
Insertion phase • Need of modulation with good Power Spectrum Density •OFDM/OQAM modulation •European project PHYDIAS •Increase the overall PAPR •Insertion under PAPR mitigation constraint
Palicot J, Louet Y, Hussain S, Zabre S, Frequency Domain Interpretation of Power Ratio Metric for Cognitive Radio Systems, Proceedings of IET Communications Journal, N° 2, pp 783-793, june 2008. T62
Nomadic RF transmitter architectures: principles and limits Possible approaches analysis J. Palicot3, G. Baudoin1, M. Villegas1, M. Suarez1
• Wireless capacity
Cooper's Law • X2 every 3 years since one century • This gain has been obtained = – – – –
X 25 using wider spectrum X 5 sharing small channels X 5 improved modulation X 1600 reduced cell sizes
We believe that the next 20 years the improvement will be given by
cognitive radio
T63
•
Vikram Chandrasekhar and Jeffrey G. Andrews, “ Femtocell Networks: A Survey “, arxiv.org/pdf/0803.0952v2.pdf
•
1
MS.Alouini and A.J.Goldsmith, “Area Spectral Efficiency of Cellular Mobile Radio Systems”, IEEE Tr on Vehicular Technology, vol 48, n°4, pp1047-1066,July 1999.
A.
Diet2,
Transmitter architectures classification M. Suarez1, M. Villegas1, G. Baudoin1 – 30 mn
Transmitter architectures classification
T64
1ESYCOM-ESIEE
(EA2552), 2L2S-DRE (UMR8506), 3Supélec IETR (UMR6164), 4Brno University of Technology (DREL), 5ST-Ericsson
Nomadic RF transmitter architectures
(Analog) RF architectures - Basics structures and theirs evolutions - New structures based on figures of merit (linearity and/or efficiency)
Digital RF architectures Conception is based on digital-RF blocs
RF architectures with "digitization" - Evolution of RF analog - New components "digitally-based"
T65
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
35
C Eb C = log 2 (RSB + 1) = log 2 + 1 B B N0
Cellulaire Tx WiMAX Tx WiFi Tx Bluetooth UWB DVB-H Rx GPS Rx T-DMB Rx
20 0 -20 -40
ASK
dBm
PSK
APSK
C/B Eb/N0
-60 -80
Modulation choice : - Data rate need + QoS - Bandwidth, coexistence, immunity - Spectral/power efficiency - Architecture design impact
-100 -120 -140 -160 -174 0
FSK
500
1000
1500
2000
2500
3000
3500
4000
5000
6000
Cellular/mobile
Connectivity UWB
GSM (900/1800)
WiMax WiFi
GSM/EDGE
TDD
T66
(H)-FDD
CSMA/CA
Bluetooth LTE
UMTS FDD/TDD
GPS DVB-H
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
CW
PAPR due to shape filtering
WB-CW
PAPR due to multi-carrier and shape filtering
T67
IR-UWB
Mean power depending on repetition frequency
IR
Frequency spectrum
PROS.
Power efficient
Time signal (with shaping filter for CW)
Multi-carrier case (ex. OFDM)
Power saving Spectrum efficient Spread spectrum
NB-CW
Typical modulation scheme
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Signal integrity : EVM, ACPR
- WiFi (25 Mbps) - WiFi (54 Mbps) - WiMAX (64-QAM) - LTE (16-QAM) - GSM/EDGE - UMTS (QPSK)
Bi : Emitted Ai
Ei EVM
Bi
T68
rms
=
Ai : Ideal 1 N
∑
A i − C 1B i − C 0
i =1
1 N
i =1
∑ =
N
∑
N
2
Ai
2
A i − Si
15 % 5.6 % 3.1 % 12.5 % 10 % 17.5 %
QPSK eye and 16-QAM for 3% EVM (rms)
Ei : Vectorial Error
N
-16 dB -25 dB -30 dB -18 dB -20 dB -15 dB
2
i =1 N
∑
Ai
2
i =1
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Signal integrity : EVM, ACPR PSD
Power level
30 dBm 25 dBm
R R0
0 dBm
P0
Padj
-25 dBm
frequency -50 dBm
ACPR =
P0 = Padj
∫
DSP (f ).df
frequency
P0
∫
DSP (f ).df
400kHz
Padj
" R = R0 + NL " ...to compare with spectral requirements Co-existence and RX sensitivity/selectivity T69
GSM/EDGE WCDMA LTE WiMAX
5MHz
10MHz
33dB 33dB 40dB
43dB 36dB 60dB
60 dB
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Signal characteristics and architecture impact Peak to Average Power Ratio (PAPRRF)
PDC PRF_in
PAPR causes variations of the input power at RF frequency NL reaction of the transceiver linearization needed (EVM, ACPR)
Device or PRF_out Front-end
η AE =
η =
PRF_out - PRF_in PDC
PRF_out PDC
LINEARITY
PA
PA
BB + BB Dig + Dig NB / WB
η peak , η mean
Pin (t )
Nomadic battery lifetime
EFFICIENCY
Architecture design FLEXIBILITY (MULTI-RADIO)
T70
COMPLEXITY
SCALEABILITY (POWER)
Selectivity, linearization, linear architecture
- Power control (avoid Near-Far for ex.)
- Additional components or devices - Stability analysis (if loop) and model - Bandwidth enhancement (tech. challenge) - Increase in current consumption - Increase in size (PB process and package)
- Adaptation to the network characteristics Channel (statistic+fading)
- Ressource management
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Realized functions in a transmitter architecture from the digital information towards the emitted micro-wave
Digital Information 0100110101
Coding and modulation scheme mapping
Digital to Analog Conversion (DAC) Baseband (symbol) frequency
Frequency transposition (in 1 or X steps) using IQ modulators and/or Modulated PLL
Power amplification (also Control) and Filtering (before/after the PA)
Connection: Duplexer, switch (loss... )
RX ?
- Spectrum/power efficiency - Data rate transfer and Bandwidth (BW) - Adaptation to the channel
- Modulators imperfections (imbalance, BW) - BW and stability of mod. PLL - Envelope information in mod. PLL ? - Phase noise of frequency synthesizer (SYNTH) - Flexibility of SYNTH + transposition
- Resolution and bandwidth limitation versus consumption - Adaptation to different signal characteristics (polar decomposition or cartesian) - State of the art new architectures T71
- Choice of the amplifier class (CW, SW...) - Impact of PA NL EVM, ACPR (model of the PA, power behavior) - Linearization or linear architecture - Filter required ( loss of efficiency)
- RX sensitivity/selectivity - (H-)FDD or TDD - loss efficiency - passive (power + HF) - MIMO ?
- Antenna (MIMO ?), package and CEM - Impact front-end - DDR and bandwidth - distortion + dispersion
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Basics architectures LO-Antenna coupling CNA RF
RF
Homo-dyne
PLL
RF
+
0 90°
HPA
Pros: - Simple Cons: - Coupling
-
LO-HPA coupling
CNA
LO2 CNA FI
Hetero-dyne
LO1 PLL
+ 0 90°
-
RF HPA
Pros: - No Coupling Cons: - Phase Noise - Nbr components
CNA
T72
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Basics architectures Polar "lite" for GSM/EDGE (small PAPR) AM detector PLL
CNA
F(p)
Modulated PLL
LO1 PLL
+
0 90°
+
VCO
RF
RF VGA
HPA
-
CNA
Angular modulation
T73
Pros: - Phase Noise/Stability Cons: - Bandwidth limited - No AM information
Bandwidth limitation :
Amplitude information :
- "in" the loop reference or feedback mod. - "over" the loop VCO input (stability ?) - "in" and "over" combination ?
- Polar lite architecture [Staszewski et al, 2005] "dynamic power supply" and polar family (w. and wo. feedback...)
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Defaults impact (IQ) I = A k .cos (ϕ k ) G.cos (ωt ) Quadrature mismatch
0 90°
PLL
G.sin (ωt + θ )
+ -
G.A k (1 + a.cos [θ]).cos (ωt + ϕ k ) 2 G.A k (1 − a.cos [θ]).cos (ωt − ϕ k ) + 2 − G.A k .a.sin [θ] sin ϕ k sin [ωt ]
Smod =
Q = a.Ak .sin (ϕ k ) + Vdc Gain imbalance
[ ]
« Offset »
+ Vdc .G.sin (ωt + θ ) a = 1.2, θ = 5°, Vdc = 0
( 1 - a.cos [θ] ) + ( 2.a.sin [θ] ) IRR = 10.log10 ( 1 + a.cos [θ] )2 2
2
T
T
T74
- sin [θ ] + V dc a.cos [θ ] cos [θ ] 0
Images of I and Q Local oscillator signal
a = 1, θ = 0°, LOR = -24 dB
2. VDC LOR = 10.log10 Ak.[1 + a.cos(θ)] I 1 I out = Q out Q - a.sin [θ ]
Transposed information
T
2
Defaults impact (PN) Synthesized frequency
Power θbref θref
VCO phase noise
Resulting phase noise
θbvco θout
Kφ.θbcomp
Kvco/p
F(p)
Reference phase noise
θcomp 1/N θbdiv Loop filter bandwidth
Koct KΦ θout =
Noise Floor Frequency
F (p) p
F (p) 1 + Kvco KΦ Np
[θ
ref
+ θbref + θbdiv + θbcomp] +
1.5
θbvco F (p) 1 + Kvco KΦ Np
1.0
0.5
0.0
-0.5
θout = G (p) [θref + θbref + θbdiv + θbcomp]
+
H(p) θbvco
-1.0
-1.5 -1.5
T75
-1.0
-0.5
0.0
0.5
1.0
1.5
Non-Linearities main characteristics (memoryless) ACPR HPA
EVM
ideal
ideal
+ Inter-modulation products
conversion
conversion and compression
conversion
conversion and compression T76
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Vdd
AM/AM (compression)
Input AM (envelope)
AM/PM
HPA
AM/AM
Non-Linearities main characteristics (memoryless)
Input AM
AM/PM (conversion)
Vdd/AM (compression)
Input "AM/Vdd" (envelope)
Vdd/PM
HPA
Vdd/AM
Input AM
Input "Vdd"
Vdd/PM (conversion) Input "Vdd" T77
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
PAPR of Multi-carriers signals (ex. OFDM) 10
C(t) = ℜ ∑ [I n(t) + jQn(t)] e jω0t e jn∆ωt n=− N/ 2 n= N/ 2
FFT FFT 10 PAPR CCDF [-]
Time domain
Time statistic
3
6000
2
5000
1
4000
0
10
FFT
10%
-1
FFT FFT
WiFi WiMAX LTE
-2
size size size size size
=256 =128 =512 =1024 =2048
3000
0
10
2000
-1
-3
1000 -2
I or Q OFDM signal
0
-3
-2.5 -2.0 -1.5 -1.0 -0.5 0.0
4
0.5
1.0
1.5
2.0
2.5
10
1500
3
-4
4
5
6
7
8 9 PAPR [dB]
2
1000
1 0 -1
EVMrms max/min (64/128) and spectrum (10 dB/step) in fct. of PAPR (lim. from -6 to 12 dB)
OFDM phase 500
-2 -3
0
-4
-4
2.5
2.0
-3
-2
-1
0
1
2
3
4
8000
OFDM envelope
10
11
12
13
6
4
0 -10
6000 -20
1.5
4000
2
-30
1.0 -40
2000
0.5
0.0 2.0E4
-50 -60
0 4.0E4
6.0E4
0.0
0.5
1.0
1.5
2.0
2.5
-70 4900
0 4950
5000
5050
5100
6
7
8
9
10
11
12
PAPR lim. + "HPA NL" LINEARISATION NEEDED T78
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Basics/classical architectures (Narrow band signals)
Hetero-dyne PB of Synthesis Noise and nbr. components
Toward wideband
Linearization by a correction technique
+ Feed-Back + Pre-Distortion (analog/digital)
Linear architecture, using a complex decomposition and recombination
Optimization of special figures of merit (efficiency η, PAPR)
CARTESIAN
LIST+ : PWM/Σ∆ coding (PAPR)
Homo-dyne
LINC CALLUM
BASICS + Feed-Back + Feed-Forward + Pre-Distortion (analog/digital)
EER Env. Tracking
PLL mod.
DOHERTY (η)
LIST+ : PWM/Σ∆ Envelope coding (PAPR)
and dynamic biasing
POLAR FULLY DIGITAL T79
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Feed-Back + PLL
HPA "A"
0 90°
-
Vdd S out A = Sin 1 + AK
|.|
K 90°
Phase is difficult to "feed-back"
Feed-Back technique : - Reduces gain and enhances linearity region - Stability of the loop (BW and TR response) - Phase is difficult to "loop" - Cartesian FB is an alternative tradeoff "nbr components Vs freedom degree (and BW)" - Thanks to ADC, digital feedback* has good performance and enable efficient adaptative algorithm
Pout (dBm)
0
Pin (dBm)
* this is also right for pre-distortion, whether the signal is in its cartesian or polar representation
T80
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Feed-Forward
+ PLL
0 90°
D. and Φ.
HPA "A"
D. and Φ.
-
D. and Φ.
Delay and
Feed-Forward technique : phase alignment - Needs lots of additional components - Always Stable - Phase control is critical - Increases the consumption (crippling for "nomadic"...) - Benefits from adaptative correction (a kind of FB+FF...) - Can be very interesting for BTS [Ghannouchi et al., 1997, FF+DPD] T81
Extraction and amplification of NL
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Pre-Distortion
HPA
P
20
Ideal, ACPR = −58.7836 Without PD, ACPR = −35.2099 Polyn. PD, ACPR = −57.6881
Pre-Distortion technique : - Digital / Baseband / IF / RF - Polar / Cartesian - Adaptative good results for ACPR reduction ! [Marsalek et al., 2003] - Memory effects (accuracy of models...) - The model is difficult (increase the complexity) - Bandwidth enhanced
power spectral densities
0
−20
−40
−60
−80
−100 0
1
2
3
4
5
6
7
8
frequency normalized by symbol frequency
T82
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
From Linearization to Linear architecture
Signal to emit
NL NL1
decomposition
NL2
The behaviour of NL components are very different Taking into account all the different parts of the transceiver : from the DAC and "digital" toward the RF/antenna
T83
correction
Towards the antenna
recombination
- Increase in complexity and Nbr components - Some new sources of defaults appears ! - keeping "nomadic" figures of merit "Linearity Vs Efficiency Vs Power Ctrl" - Flexibility ? ( multi-radio)
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Avoiding AM/AM and AM/PM : LINC LInearization with Non-Linear Components, [Cox]
[
I + j.Q = R (t ).e jΦ ( t ) = r0 . e j(Φ ( t )+ θ ( t )) + e j(Φ ( t )−θ ( t )) Baseband complex information
r0 ) R(t
+θ(t)
Constant envelope signal n°1
T84
AM = Constant no AM/AM no AM/PM
+ HPA -
r0 .sin (Φ (t ) − θ (t ))
PLL
LINC : - 2x PA and IQ Mod. - LOSS of Combiner - Decomposition complexity - Bandwidth - 2x Phase noise
Constant envelope signal n°2
r0 .cos (Φ (t ) − θ (t ))
Φ(t) -θ(t)
]
r0 .cos (Φ (t ) + θ (t ))
0 90°
+ HPA -
LOSSES !
r0 .sin (Φ (t ) + θ (t ))
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
LINC CALLUM Combined Analogue Locked Loop Universal Modulator [Bateman] I(t)
VCO
HPA
LINC part
Q(t)
HPA
VCO -
PLL
T85
0 90°
LINC CALLUM: - 2x PA and VCO. - LOSSES of the combiner - Decomposition less complex - Bandwidth and stability (dual loop)
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Avoiding AM/AM and AM/PM : EER Envelope Elimination and Restoration, [Khan] R(t) e j Φ(t)
e j Φ(t)
I (t ) + jQ (t ) = R(t ) e
R=1
Φ(t) R(t)
101010 D E C O M P O S I T I O N
T86
CNA
001101
R(t ) = I²+Q²
CNA cos (Φ) =
011001
CNA
sin (Φ) =
I I² + Q²
jΦ( t )
EER : - High efficiency HPA - Decomposition complexity - Bandwidth of Signals - Synchronisation - Envelope coding efficiency
PWM or Σ∆ coding
+ PLL
0 90°
-
H. E. HPA
Q I² + Q²
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Envelope Tracking and dynamic biasing techniques ET : - High efficiency HPA + driving signal - Synchronisation - Envelope coding efficiency - PAPR and clipping
Dynamic biasing (input and/or output) "Tracking" the supplied DC power
101010 D E C O M P O S I T I O N
T87
CNA
001101
PWM or Σ∆ coding or converter
R(t ) = I²+Q²
CNA + PLL
011001
0 90°
-
H. E. HPA
CNA
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Polar architecture for nomadic multi-radio - RF carrier frequency and bandwidth (high data rate) - Power scaleability (average and dynamic) - Linearity and efficiency ∀ modulation scheme and frequency (flexibility)
Slow control of the carrier frequency Frequency control Power control
Flexibility/tuning
Slow control of the average power Supply modulation Amplitude : ρ(t) Σ∆ or PWM or...
Modulated signal
Phase : φ(t)
PLL
"HPA" + Filtering NT
Front-end pass-band profile T88
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
BW limitation
Efficiency Sensitivity improvement to PAPR
Complexity
transfer complexity to digital
Increase in size
Frequency flexibility
Power scaleability
Main imperfections sources
FB
loop
medium
-
low
possible
low
loop
-
Stability, BW
FF
-
low
-
high
difficult
high
PA
-
Model, consumption
PD (DPD)
-
high
-
can be very high
yes
-
PD or
-
Need of adaptability (complex)
very high
difficult (decomp. possible)
high
loop and
-
Decomposition (complex) Recombination (loss)
yes
Synchronisation BW Envelope coding efficiency
yes
PA driving Envelope coding efficiency
Transposed signals LINC enhance BW combiner to mod. (CAL.) (2 loops) index
phase EER
ET
T89
Signal BW, DC/DC converter
DC/DC converter
high
PA
yes (clipping)
high
decomp. possible
high
DPD
combiner
PA
AM coding ?
high PA
yes (clipping)
high
AM coding ?
high
PA
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Considerations for multi-radio: Signal PAPR and data rate ↔ EVM, ACPR , co-existence Signal BW and stability ! DAC state-of-the-art challenge Multi-radio + BW "open-loop" appreciated (ET, EER...) Output filtering must be considered more compared to NL Filtering front end ? Filtering PA ? Filtering antenna ? (flexibility ?) filters banks are currently necessary but lowers the efficiency
Observations/trends 1) Linear architectures (LINC, EER, ET,...) can highly benefit from Pre-distorsion, (digital decomposition, interfaced with the DPD algorithm) increase in complexity 2) Techniques for reducing the PAPR or its NL influence complete "linearization" but the complexity is often shifted to another figure of merit such as efficiency, selectivity... 3) Improving peak and average efficiency (cf. signal stat.) is a challenging lock for "nomadic". Often, this is not compatible with flexibility... a precise knowledge of the PA design is so mandatory (next part) T90
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Improving the efficiency of a PA : Doherty 4
Ideal generator 2
Ideal generator 1
R = 1, I normalised
3
R0 = 2R
I1
I2
λ/4
I2 I1
2 1
R
0 0
200
400
600
800
1000
5
R ingen 1
4 gen 1 + λ
R in
3
I Ringen 1 = R 1 + 2 I1
I Ringen 2 = R 1 + 1 I2
R0 = 2R
2
R
T91
R02 = gen1 Rin
R ingen 2
1 0
gen1+ λ 4 in
4
200
400
600
800
1000
Modification of load lines for both PAs R decreases evolution from class A to AB, B or C ! (it means: improving the efficiency)
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Improving the efficiency of a PA : Doherty
Main "PA" i.e. Gen. 1
+ PLL
PA
0 90°
-
λ/4
τ
Auxiliary "HPA" i.e. Gen. 2
η Main PA
Main and auxiliary PA
Pin T92
HPA
Doherty : - PA + High efficiency PA (2) - Design with load-pull - Efficiency improvement (average and peak) - Narrow band ! (λ/4)
Evolution of LIST thanks to PWM and Σ∆ (LInear amplification employing Sampling Techniques) - The use of LIST technique is known for many years.... but not at GHz ! - It provides the amplification of "coded AM" with a switched PA - Avoid AM PAPR avoid PA NL ! - The AM should be restored after amplification by filtering - The efficiency is : [ PA efficiency ] X [ coding efficiency ]
+ PLL
0 90°
-
T93
Σ∆/PWM modulator
PA
Performances are the major technical lock
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Evolution of LIST thanks to PWM and Σ∆ (LInear amplification employing Sampling Techniques) Envelope
Σ∆ coder
Polar Σ∆
Cartesian Σ∆
Power reflected to the PA T94
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
RF Filtering need - If Σ∆ or PWM - For multi-radio - Spectrum mask
Rejection of the spectral regrowths Poor efficiency due to the AM coding Coexistence !
LC Filters : (-) Frequency (-) Size (-) Quality factor
Ceramic Filters : (+) Low IL and cost (-) Integration (-) Size
SAW* Filters : (-) Size (-) Frequency (-) Output power (-) Integration IC
LTCC** Filters : (+) Good rejection / low IL (+) Higher fmax than others. (-) Integration process
BAW*** Filters : (+) Good Rejection, low IL (+) Higher fmax than others. (+) Integrated “above IC” / Size reduction. SAW*: Surface Acoustic Wave T95
LTCC**: Low Temperature Co-Fired Ceramic
BAW***: Bulk Acoustic Wave
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
The antenna influence
50 Ohms
50
Antenna impedance
0
- Modification of the bandwidth and adaptation
-10
- Out of band emission (see harmonic opt. of SW class E and J PAs, for ex.)
-20
-30
- Why 50 Ohms for PA "filtering output NT" ? -40 2.5
T96
3.5
4.5
5.5
6.5
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Co-design principle
ZNL
ZTX
channel
- Channel and antennas impact the front-end design - Antenna impedance modifies the NLs of the PA (+filter) - Electrical model of the antenna ? modification of the geometry under constraints...
T97
ZRX
S ( f, θ, φ, p)
Rad. characteristics DDR mod.
PA/Ant. coupling (CEM)
ZTX
PA NLs modification
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Need of a complete front-end co-design
Front end blocs (PA/filter/duplexer/antenna) challenge for multi-radio
T98
- PA :
Efficiency, flexibility, power scaleability
- Filter :
Avoid ? Bank (losses) ? Enough selectivity ? Integration and cost
- Duplexer :
Losses and flexibility (?)
- Antennas :
Multi-band (relax filter selectivity) Multi-antennas losses but selective
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
Some References - Andia, L. et al. Specification of a Polar Sigma Delta Architecture for Mobile Multi-Radio Transmitter - Validation on IEEE 802.16e. Proc. of IEEE Radio and Wireless Symposium, pp. 159-162, Orlando, USA. Jan. 2008. - Baudoin, G. et al. Radiocommunications Numériques : Principes, Modélisation et Simulation. Dunod, EEA/Electronique, 672 pages, 2ème édition 2007. - Baudoin, G. et al. Influence of time and processing mismatches between phase and envelope signals in linearization systems using EER, application to hiperlan 2. Proc Conf. IEEE - MTT'2003 Microwave Theory and Technique, Philadelphia USA, June 2003. - Choi, J. et al. A ΣΔ digitized polar RF transmitter. IEEE Trans. on Microwave Theory and Techniques, Vol. 52, n°12, 2007, pp 2679-2690. - Cox, D. Linear amplification with non-linear components, LINC method. IEEE transactions on Communications, Vol COM-23, pp 1942-1945, December 1974. - Diet, A. et al. Flexibility of Class E HPA for Cognitive Radio. IEEE 19th symposium on Personal Indoor and Mobile Radio Communications, PIMRC 2008, 15-18 september, Cannes, France. CD-ROM ISBN 978-1-4244-2644-7. - Diet, A., Baudoin, G., Villegas, M. Influence of the EER/polar Transmitter Architecture on IQ Impairments for an OFDM Signal. International Review of Electrical Engineering, IREE Praise Worthy Prize, ISSN 1827-6660, V-3 N-2, March-April 2008, pp 410-417. - Diet, A., Baudoin,G., Villegas, M., Robert, F. Radio-Communications Architectures, pp. 1-35 , Chapter n°1 of “Radio-Communications” edited by Alessandro Bazzi, ISBN 978-953-307-091-9, INTECH (SCIYO), 712 pages, april 2010. - Dürdodt, D. et al. A low-IF Rx two-point ΣΔ-modulation Tx CMOS single-chip bluetooth solution. IEEE Trans. MTT, vol. 51, no. 9, pp. 1531–1537, Sep. 2001. - Eloranta, P., Seppinen, P., Parssinen, A. Direct-digital RF-modulator: a multi-function architecture for a system-independent radio transmitter. Com. Magazine, IEEE, V46, I4, 2008, pp 144-151. - Groe, J. A Multimode Cellular Radio. IEEE Trans. On circuits and systems—II: Express briefs, Vol. 55, No. 3, March 2008, pp. 269-273. - Groe, J. Polar Transmitters for Wireless Communications. IEEE Communications Magazine September 2007, pp. 58-63. - Hibon, I. et al. Linear transmitter architecture using a 1-bit ΔΣ. European Microwave Week 2005, Proc. Conf. ECWT, pp. 321-324, Octobre 2005. - Jardin, P., Baudoin, G. Filter Lookup Table Method for Power Amplifier Linearization. IEEE Trans. on Vehi. Tech., N° 3, Vol. 56, pp. 1076-1087, IEEE, Mai 2007. - Jeong, J., Wang, Y. A Polar Delta-Sigma Modulation (PSDM) Scheme for High Efficiency Wireless Transmitters. IEEE MTT-S Int. Microwave Symp. Dig. June 2007. - Kahn, L. Single Sideband Transmission by Envelope Elimination and Restoration. Proc. of the I.R.E., 1952, pp. 803-806. - McCune, E. Polar Modulation and Bipolar RF Power Devices. IEEE Bipolar/BiCMOS Circuits and Technology Meeting (BCTM), October 2005. - McCune, E. High efficiency, multimode, multiband terminal power amplifiers. IEEE Microwave Magazine, March 2005, Volume: 6, Issue: 1, pp: 44- 55. - Murmann, B. Digitally Assisted Analog Circuits – A Motivational Overview. IEEE International Solid-State Circuits Conf.: Special Topic Evening Session, Febr. 2007. - Nielsen, M., Larsen, T. Transmitter Architecture Based on ΔΣ Modulation and Switched Power Amplification. IEEE Trans. on Circuits and Syst. II, 2007, vol. 54, no. 8, pp. 735-739. - Robert, F. et al. Study of a polar ΔΣ transmitter associated to a high efficiency switched mode amplifier for mobile Wimax. 10th annual IEEE Wireless and Microwave Technology Conference, WAMICON, april 2009, Clearwater, FL, USA. - Rode, J., Hinrichs, J., Asbeck, P. Transmitter architecture using digital generation of RF signals. IEEE Radio and Wireless Conf., pp. 245-248, August 2003. - Sowlati, T. et al. Quad band GSM/GSM/GPRS polar loop transmitter. IEEE Journal of Solid-State Circuits, Volume 39, Issue 12, Dec. 2004 Page(s): 2179 – 2189. - Suarez Penaloza, M. et al. "Study of a Modified Polar Sigma-Delta Transmitter Architecture for Multi-Radio Applications", EuMW, 27-31 Octobre 2008, Amsterdam. - Suarez Penaloza, M. et al. "A Cartesian Sigma-Delta Transmitter Architecture", Proc. of IEEE Radio and Wireless Symposium, USA. Jan. 2009. - Villegas, M. et al. Radiocommunications Numériques : Conception de circuits intégrés RF et micro-ondes. Dunod, EEA/Electronique, 464 pages, 2ème édition 2007. - Wendell, B. et al. Polar modulator for multi-mode cell phones. Proceedings of the IEEE 2003 Custom Integrated Circuits Conference, Sept. 2003, pp: 439 – 44. T99
Nomadic RF transmitter architectures: principles and limits Transmitter architectures classification A. Diet2, M. Suarez1, M. Villegas1, G. Baudoin1
M.
Villegas1,
High efficiency amplifiers A. Diet2, L. Andia1, F. Robert1,5 – 40 mn
High efficiency amplifiers
T100
1ESYCOM-ESIEE
(EA2552), 2L2S-DRE (UMR8506), 3Supélec IETR (UMR6164), 4Brno University of Technology (DREL), 5ST-Ericsson
M.
Villegas1,
High efficiency amplifiers A. Diet2, L. Andia1, F. Robert1,5 – 40 mn
• Power amplifier classification
• Conventional power amplifiers
• Switch mode power amplifiers
• Technologies used for power amplifiers
T101
Power amplifier (PA) classification ? Different classifications in the literature
Conventional mode
Class A
50%
Class AB
Class B
Switching mode
Class C
Class F
78,5%
Class D, E, S
100% Theoritical Efficiency
Linear
Non linear Linearity
T102
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Power amplifier classification : linearity versus efficiency Why high efficiency is important ? Increased power consumption Battery cost Electrical power expenses Environmental incentive Deterioration of semiconductor reliability
the final power amplifier dominates the total power consumption Linear
100%
Linearity
Efficiency
78,5% -
A T103
AB
C
F
D ,E ,S
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Conventional power amplifier principles ? Some PA characteristics :
Peak output power determined by its saturation
Peak ouput power
PA efficiency maximum close to saturation
Peak efficiency
Operating point near compression induced distortion
Power gain
PA operating point depends on the input signal PAPR
Amplifier linearity
Backoff needed for high PAPR efficiency reduction
Stability
Example : Transmitted WCDMA signal
Average efficiency
1 dB Output power (dBm)
Pout1dB
T104
40
20
RF signal power
Non linear area
RF signal power
Linear area
40
0 -20 -40 -60 2125
2130
2135 2140 2145 Frequency [MHz]
2150
2155
30
20
10
0 50
51
52 53 Time [µs]
54
Peak power: 40.3 dBm Faible Low rendement efficiency
Haut High rendement efficiency
Pin1dB Input power (dBm)
Average power: 30.0 dBm Peak-to-average: 10.3 dB Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
55
Conventional power amplifier characteristics ? Intermodulation
Efficiency
PRFin
η =
PRF ( S ) PDC
G
ηPAE =
P5thOrd_low P3rdOrd_low Pfund_low
PDC PRFout
PRF(S) − PRF(E) PDC AM-AM AM-PM
20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 -40
-35
-30 -25 -20 -15 -10 RFpower
-5
Most important conventional PA characteristics : Output power at compression point Intermodulation products AM-AM and AM-PM characteristics Efficiency
T105
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Conventional power amplifier characteristics ?
Intermodulation product measurement :
Increased power
3th order intermodulation 5th order intermodulation
T106
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
PSD
Impact of non linearity on system characteristics System main features : ACPR and EVM
R R0
ACPR =
P0 = Padj
∫
DSP (f ).df
P0
∫
DSP (f ).df
Padj
P0
Padj frequency
Example : 16 QAM constellation Bi : Emitted Ai
Ai : Ideal
Ei
EVM Bi
T107
rms
=
Ei : Vectorial Error
1 N
N
∑
A i − C1B i − C 0
i =1
1 N
i =1
∑ =
N
∑
N
2
Ai
2
A i − Si
2
i =1 N
∑
Ai
2
i =1
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Impact of non linearity on system characteristics Constant envelope signal t
HPA
f
f
Non constant envelope signal t
HPA
f
f T108
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Impact of non linearity on system characteristics
1 dB ba ck -of f
Output power
Edge GSM : signal analysis after AB class amplifier
1dB compression point LINEARITY EFFICIENCY
T109
Input power
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Power amplifier classification : current source versus switching mode Conventional mode (A, AB, B, C)
Supply Inductor
Supply
Switching mode (D, E, F) Inductor
charge
Output Network
T110
charge
Output Network
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
M.
Villegas1,
High efficiency amplifiers A. Diet2, L. Andia1, F. Robert1,5 – 40 mn
• Power amplifier classification and characteristics
• Conventional power amplifiers
• Switch mode power amplifiers
• Technologies used for power amplifiers
T111
Peak output power determined by its saturation PA efficiency maximum close to saturation Operating it into compression results in severe distortion
Pout [dBm], PAE [%], Prob. [%]
Conventional power amplifier based on current source Transistor used as variable courant source
The total PA efficiency is weighted by the signal input power probability density function Optimal choice : class AB operation linearity and efficiency trade-off most favorable
30 Pout PAE Prob.
25 20 15 10 5 0 -25
-20
-15 -10 -5 Input power [dBm]
0
5
60 Voltage Current Dissipated power
50 40
Simultaneous voltage and current Dissipation across the device Limits practical efficiency to < 50% How can the voltage×current overlap be minimized ? By using switch mode amplifier
30 20 10 0
0
0.2
0.4
0.6
0.8
1
Time
T112
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Conventional power amplifier based on current source Power amplifier class definition : Vgg
Vgg
Z in Input matching network
CDC
CDC
Output matching
network *= ZS Z in
ZS
ZL . .
T113
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Conventional power amplifier based on current source Power amplifier conduction angle definition : VDC
2π
2VDC max
Gate voltage
0V D G
Vpinch-off
θ
T114
RF output signal
-VRF
LOAD
RF input signal
S
Resonant circuit
Nomadic RF[...] High efficiency amplifiers M. Villegas1, A. Diet2, L. Andia1, F. Robert1,5
Conventional power amplifier based on current source Class
Theoretical efficiency
Active device
Conduction angle
A
50%
ON 100%period
2π
AB
50 78,5%
ON > 50% period
π 2π
B
78,5%
ON 50% period
π
C
> 78,5%
ON < 50% period