Modeling of Digital Communication Systems using Simulink Chap
- Slides: 34
Modeling of Digital Communication Systems using Simulink Chap 10. Digital Communications BER Performance in AWGN (Block Coding and Fading) Chap 11. Digital Communications BER Performance in AWGN and Fading (Convolution Coding) EMLAB
1 목차 Chap 10. Digital Communications BER Performance in AWGN (Block Coding and Fading) 10. 1 Digital Communications with Block Coding in Fading 10. 2 BER Performance of BPSK in Rayleigh Fading with Interleaving and a BCH Block Code 10. 3 BER Performance of BFSK in Rayleigh Fading with Interleaving and a Golay(24, 12) Block Code 10. 4 BER Performance of 32 -FSK in Rayleigh Fading with Interleaving and a Reed-Solomon(31, 15) Block Code 10. 5 BER Performance of 16 -QAM in Rayleigh Fading with Interleaving and a Reed-Solomon(15, 7) Block Code 10. 6 BER Performance of 16 -QAM in Rayleigh and Rician Fading with Interleaving and a Reed. Solomon(15, 7) Block Code 10. 7 BER Performance of BPSK in Rayleigh Fading with Interleaving and a BCH Block Code and Alamouti STBC 10. 8 BER Performance of BFSK in Rayleigh Fading with Interleaving and a Golay(24, 12) Block Code and Alamouti STBC 10. 9 BER Performance of 32 -FSK in Rayleigh Fading with Interleaving and a Reed-Solomon(31, 15) Block Code and Alamouti STBC 10. 10 BER Performance of 16 -QAM in Rayleigh Fading with Interleaving and a Reed-Solomon (15, 7) Block Code and Alamouti STBC EMLAB
2 Chap 11. Digital Communications BER Performance in AWGN and Fading (Convolutional Coding) 11. 1 Digital Communications with Convolutional Coding 11. 2 BER Performance of Convolutional Coding and BPSK in AWGN 11. 3 BER Performance of Convolutional Coding and BPSK in AWGN and Rayleigh Fading with Interleaving (Soft- and Hard-Decision Decoding) 11. 4 BER Performance of Convolutional Coding and BPSK and Alamouti STBC in Rayleigh Fading with Interleaving EMLAB
3 10. 4 BER Performance of 32 -FSK in Rayleigh Fading with Interleaving and a Reed-Solomon(31, 15) Block Code • 32 -FSK in Rayleigh Fading with Interleaving and a RS (31, 15) Block Code EMLAB
4 10. 4 BER Performance of 32 -FSK in Rayleigh Fading with Interleaving and a Reed-Solomon(31, 15) Block Code • BER 성능 EMLAB
5 10. 5 BER Performance of 16 -QAM in Rayleigh Fading with Interleaving and a Reed-Solomon(15, 7) Block Code • 16 -QAM in Rayleigh Fading with Interleaving and a RS (15, 7) Block Code EMLAB
6 10. 5 BER Performance of 16 -QAM in Rayleigh Fading with Interleaving and a Reed-Solomon(15, 7) Block Code • BER 성능 EMLAB
7 10. 5 BER Performance of 16 -QAM in Rayleigh Fading with Interleaving and a Reed-Solomon(15, 7) Block Code • Rayleigh Fading Channel 의 Maximum Doppler shift 0. 1 Hz 및 0. 01 Hz 인 경우 EMLAB
8 10. 6 BER Performance of 16 -QAM in Rayleigh and Rician Fading with Interleaving and a Reed-Solomon(15, 7) Block Code • 16 -QAM in Rayleigh and Rician Fading with Interleaving and a RS(15, 7) Block Code EMLAB
9 10. 6 BER Performance of 16 -QAM in Rayleigh and Rician Fading with Interleaving and a Reed-Solomon(15, 7) Block Code • BER 성능 EMLAB
10 10. 7 BER Performance of BPSK in Rayleigh Fading with Interleaving and a BCH Block Code and Alamouti STBC • BPSK in Rayleigh Fading with Interleaving and a BCH Block Code and Alamouti STBC EMLAB
11 10. 7 BER Performance of BPSK in Rayleigh Fading with Interleaving and a BCH Block Code and Alamouti STBC • BER 성능 EMLAB
12 10. 8 BER Performance of BFSK in Rayleigh Fading with Interleaving and a Golay(24, 12) Block Code and Alamouti STBC • BFSK in Rayleigh Fading with Interleaving and a Golay(24, 12) Block Code and Alamouti STBC EMLAB
13 10. 8 BER Performance of BFSK in Rayleigh Fading with Interleaving and a Golay(24, 12) Block Code and Alamouti STBC • BER 성능 EMLAB
14 10. 9 BER Performance of 32 -FSK in Rayleigh Fading with Interleaving and a Reed-Solomon(31, 15) Block Code and Alamouti STBC • 32 -FSK in Rayleigh Fading with Interleaving and a RS (31, 15) Block Code and Alamouti STBC EMLAB
15 10. 9 BER Performance of 32 -FSK in Rayleigh Fading with Interleaving and a Reed-Solomon(31, 15) Block Code and Alamouti STBC • BER 성능 EMLAB
16 10. 10 BER Performance of 16 -QAM in Rayleigh Fading with Interleaving and a Reed-Solomon (15, 7) Block Code and Alamouti STBC • 16 -QAM in Rayleigh Fading with Interleaving and a RS(15, 7) Block Code and Alamouti STBC EMLAB
17 10. 10 BER Performance of 16 -QAM in Rayleigh Fading with Interleaving and a Reed-Solomon (15, 7) Block Code and Alamouti STBC • BER 성능 EMLAB
18 11. 1 Digital Communications with Convolutional Coding • 11장의 내용은 AWGN 채널 및 Fading channel 에 convolutional error control coding 을 적용하는 방법을 소개한다. • BPSK 의 BER 성능을 아래 세 가지 환경에서 알아본다. § AWGN 에서 convolutional coding 을 적용한 경우 - Hard & Soft-decision decoding § AWGN 및 Rayleigh fading channel 일 때 convolutional coding 을 적용한 경우 - Hard & Soft-decision decoding § Rayleigh fading channel 일 때 convolutional coding 및 Alamouti STBC 적용한 경우 - Hard & Soft-decision decoding EMLAB
20 11. 2. 1 Hard-Decision Decoding • Simulink 의 convolutional encoder 및 decoder 는 trellis (격자) 구조를 이용하여 8진수로 표현된 다항식 및 피드백 탭 정보를 구현함. • 매트랩 함수 poly 2 trellis(7, [171, 133]) 7: shift register 에 저장되는 비트 수, 171 : 1111001, 133 : 1011011 EMLAB
21 • State Diagram / Trellis Diagram EMLAB
22 11. 2. 1 Hard-Decision Decoding (cont’d) • Convolutional coding 을 적용한 BPSK 의 BER 특성을 보기 위한 시뮬링크 모델 ✔ ✔ EMLAB
23 11. 2. 1 Hard-Decision Decoding (cont’d) • Convolutional Encoder EMLAB
24 11. 2. 1 Hard-Decision Decoding (cont’d) • Viterbi Decoder 복호 시 지연 : code rate ½ 인 경우 보통 constraint length의 다섯배 정도의 값을 씀. EMLAB
25 • Decode 원리 (에러가 없음, 현재 상태가 00 임을 가정할 때) If ip=0 If ip=1 Current state Next state (op) 00 00 (00) 10 (11) 01 00 (11) 10 (00) 10 01 (10) 11 (01) 11 01 (01) 00/X : op/hamming distance 11 (10) 00 00/2 11/0 10 11/2 10/2 01 00/0 10/2 01/0 11 10/2 Rx data 11 01 01 00 01 Tx data 1 1 0 1 1 EMLAB
26 • Decode 절차 (에러가 있는 경우, Hard-decision) If ip=0 If ip=1 Current state Next state (op) 00 00 (00) 10 (11) 01 00 (11) 10 (00) 10 01 (10) 11 (01) 11 01 (01) 00/X : op/hamming distance 11 (10) 00 00/2 11/0 10 00/1 11/1 11/0 00/2 01 10/2 00/1 10/2 01/0 11 10/2 Rx data 11 01 01 10 01 Tx data 1 1 1 EMLAB
27 • Decode 절차 • Hard – decision decoding • Hamming distance 를 계산하여 그 거리가 최소인 경로로 결정. ex. ) 010→ 111 해밍거리: 2 100→ 011 해밍거리: 3 0110→ 1110 해밍거리: 1 0100→ 1001 해밍거리: 3 EMLAB
28 • Decode 절차 • Soft – decision decoding • Euclidean distance 를 계산하여 그 거리가 최소인 경로로 결정. ex. ) (a) Hard-decision plane (b) 8 -level by 8 -level softdecision plane (c) Example of soft code symbols (d) Encoding trellis section (e) Decoding trellis section. EMLAB
29 11. 2. 1 Hard-Decision Decoding (cont’d) • Viterbi Decoder – Decision Type - decoder 입력 데이터 타입이 달라짐. Unquantized: 실수를 받으며 양의 실수: logic 0, 음의 실수: logic 1 로 인식 Hard-Decision: 0, 1 을 받으며 0: logic 0, 1: logic 1로 인식 Soft-Decision: 0 ~ 2 b-1 의 정수를 받으며 b 는 soft decision 비트의 개수. Input Value Interpretation 0 Most confident zero 1 Second most confident zero 2 Third most confident zero 3 Least confident zero 4 Least confident one 5 Third most confident one 6 Second most confident one 7 Most confident one EMLAB
30 11. 2. 1 Hard-Decision Decoding (cont’d) • BER 성능 EMLAB
31 11. 2. 2 Soft-Decision Decoding • Convolutional coding 을 적용한 BPSK 의 BER 특성을 보기 위한 시뮬링크 모델 EMLAB
32 11. 2. 2 Soft-Decision Decoding (cont’d) • Scalar Quantizer Encoder boundary points 에 정해진 양자화 범위로 (index) 입력값을 대응시켜줌. partitioning ex. ) Bounded: [0 0. 5 3. 7 5. 8 6. 0 11] 0 0 1 4 Unbounded: [0 0. 5 3. 7 5. 8 6. 0 11] 1 2 5 6 EMLAB
33 11. 2. 2 Soft-Decision Decoding (cont’d) • BER 성능 EMLAB