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시스템별 스펙정리
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IEEE a IEEE n
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IEEE 802.11a (1) Rate-dependent parameters
Table 1 Modulation-dependent normalization factor KMOD
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IEEE 802.11a (2) Rate-dependent parameters (Cont’)
Fig. 1 BPSK, QPSK and 16QAM constellation bit encoding Table 2 BPSK, QPSK and 16QAM encoding table
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IEEE a (3) Fig. 2 64QAM constellation bit encoding
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IEEE 802.11a (4) Convoultional encoder
Rate R=1/2 code with generator polynomials g0=1338 and g1=1718 Higher rates are derived from it by employing “puncturing” R=2/3 or 3/4 Decoding by Viterbi algorithm is recommended
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IEEE a (5) Convoultional encoder (Cont’)
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IEEE n (1) Rate dependent parameters for high throughput modulation and coding schemes Table 1 Symbols used in rate dependent parameters tables Table 2 Rate dependent parameters for mandatory 20MHz
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IEEE 802.11n (2) Convoultional encoder
A single FEC encoder is used when the PHY rate is less than or equal 300Mbps or when LDPCC ECC is used. Rate = ½ code Higher rates are derived from it by employing “puncturing” R=2/3, 3/4 or 5/6
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MB-OFDM UWB
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MB-OFDM UWB (1) Data rate-dependent modulation parameter
Data Rate (Mb/s) Modulation Coding rate (R) Conjugate Symmetric Input to IFFT Time Spreading Factor (TSF) Overall Spreading Gain Coded bits per OFDM symbol (NCBPS) 53.3 QPSK 1/3 Yes 4 100 80 1/2 106.7 11/32 No 2 200 160 5/8 320 DCM 1 400 480 3/4 Table 1 Modulation-dependent normalization factor KMOD Modulation KMOD QPSK 1/2 Table 2 QPSK encoding table Input bit (b0 b1) I-out Q-out 00 -1 01 1 10 11 Fig. 1 QPSK constellation bit encoding
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MB-OFDM UWB (2) Data rate-dependent modulation parameter (Cont’)
Interleaver 1 st 16 - point Mapper S / P : 2 IFFT 100 bits nd 50 tone separation Fig. 2 Block diagram of DCM Fig point constellations
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MB-OFDM UWB (3) Convolutional encoder
Rate R=1/3 code with generator polynomials g0=1338, g1=1658, and g2=1718 Additional coding rates are derived from the rate R = 1/3 convolutional code by employing “puncturing” R=1/3, 11/32, ½, 5/8, or 3/4 Decoding by Viterbi algorithm is recommended D Output Data A Output Data B Output Data C Fig. 4 Convolutional encoder: rate R=1/3, constraint length K=7
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MB-OFDM UWB (4) Convolutional encoder (Cont’)
Fig. 5 An example of the bit-stealing and bit-insertion procedure (R=11/32)
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T-DMB
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T-DMB (1) 지상파 DMB 개념도 DAB (Eureka-147) PAD NPAD FIC MSC Audio Service
MPEG4 LIVE TV Block Code DAB (Eureka-147) FIC MSC Service Data Service K-DMB Service FIDC 2 Ch Multi Ch. D L S MOT IP Tunneling TDC MPEG4 A/V Data MCI & SI T C EWS Broadcasting Web Site Interactive Service JPEG Slide Show TPEG, DGPS etc
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T-DMB (2) DAB (Eureka-147) 구조도
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T-DMB (3) Convolutional Coding (Mother Code) P/S Constraint: 7
Memory: 6 Code rate: ¼ Generating polynomial: (133, 171, 145, 133)o all-zero initial state of the shift register Output codeword P/S To puncturing procedure
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T-DMB (4) Puncturing Block Mother code의 일부 bit가 결정된 순서에 따라 전송되지 않음
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T-DMB (5) Puncturing Block (cont’d)
vPI,i = 0 : the corresponding bit shall not be transmitted vPI,i = 1 : the corresponding bit shall be transmitted
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T-DMB (6) Phase Reference Symbol
Reference for the differential modulation for the next OFDM symbol Mode II
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T-DMB (7) QPSK Symbol Mapper
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T-DMB (8) Differential Modulation
Applied to the QPSK symbols on the same carriers between two consecutive OFDM symbols 8 possible phase states
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Wibro
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WiBro IEEE 802.16 + Wibro (1) 2.3GHz 휴대인터넷 국내 기술 기준 60km/h로 이동시,
셀 경계에서 최소 하향 512kbps, 상향 128kbps 보장 채널대역폭 ≥ 9 MHz 사업자 장비간 로밍 가능 주파수 재사용계수 = 1 이중화 방식 = TDD (송수신 time slot간 동기 일치) IEEE + WiBro 주요 파라미터 사용 대역 2.3 GHz 채널 대역폭 8.75 MHz 프레임 길이 5ms 다중접속방식 OFDMA 이중화 방식 TDD FFT 크기 1024 변조 방식 QPSK, 16-QAM, 64-QAM 채널 부호화 Convolutional Turbo Code ARQ Hybrid ARQ
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Wibro (2) Wibro 송수신 블록도
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Wibro (3) Convolution Turbo Code (CTC)
Dual binary circular recursive systematic convolutional (CRSC)
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Wibro (4) CTC interleaver First permutation Second permutation
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Wibro (5) Mapping QPSK 16QAM 64QAM
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CDMA (IS-95) WCDMA
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CDMA (1) System parameter Duplex mode : FDD and TDD
Ddata modulation : QPSK(downlink) BPSK(uplink) Channel coding : convoultional and turbo codes Convolutional coding rate = 1/3 or ½ with constraints length 9 Turbo coding rate = 1/3 Turbo coding scheme is a parallel concatenated convoultional code (PCCC) with 8 state constituent encoders Fig. 1 Overall eight-state PCCC turbo coding
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CDMA (2) Convolutional Encoder
Forward Link & Rate set 2 Reverse Link ; R = 1/2, K = 9, g0 = 753(8)= (2) g1 = 561(8)= (2) ‘1’ : Connection ‘0’ : Disconnection ex) Forward link g0 c0 Data bits input Code Symbols Output g1 c1
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CDMA (2) CMDA 순방향채널의 I, Q 데이터와 위상 1 I Q 위상 /4 3/4 -3/4 -/4
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WCDMA (1) System parameter Duplex mode : FDD and TDD
Ddata modulation : QPSK(downlink) BPSK(uplink) Channel coding : convoultional and turbo codes Convolutional coding rate = 1/3 or ½ with constraints length 9 Turbo coding rate = 1/3 Turbo coding scheme is a parallel concatenated convoultional code (PCCC) with 8 state constituent encoders Fig. 1 Overall eight-state PCCC turbo coding
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WCDMA (2) Modulation The complex-valued chip sequence generated by the spreading process is QPSK modulated The pulse shaping is root-raised cosine with roll-off factor 0.22 and is the same for the mobile and base stations Fig. 2 Modulation principle
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