Multi-Carrier and Spread Spectrum Systems: From OFDM and MC ...

Channel Coding and Decoding 177Table 4-3 E s /N 0 for punctured convolutional codes with perfect CSI for M-QAM modulationin AWGN, independent Rayleigh, and Ricean fading channels for BER = 2 × 10 −4Modulation CC rate R AWGN Ricean fading Rayleigh fading(Rice factor 10 dB)1/2 3.1 dB 3.6 dB 5.4 dB2/3 4.9 dB 5.7 dB 8.4 dBQPSK 3/4 5.9 dB 6.8 dB 10.7 dB5/6 6.9 dB 8.0 dB 13.1 dB7/8 7.7 dB 8.7 dB 16.3 dB1/2 8.8 dB 9.6 dB 11.2 dB2/3 11.1 dB 11.6 dB 14.2 dB16-QAM 3/4 12.5 dB 13.0 dB 16.7 dB5/6 13.5 dB 14.4 dB 19.3 dB7/8 13.9 dB 15.0 dB 22.8 dB1/2 14.4 dB 14.7 dB 16.0 dB2/3 16.5 dB 17.1 dB 19.3 dB64-QAM 3/4 18.0 dB 18.6 dB 21.7 dB5/6 19.3 dB 20.0 dB 25.3 dB7/8 20.1 dB 21.0 dB 27.9 dBDataOuter encoder:ShortenedReed–Solomon codeInterleaving(optional)Inner encoder:Puncturedconvolutional codeTo mappingTxDataOuter decoder:Reed–SolomondecoderInterleaving(optional)Inner decoder:Viterbi decoderFromdemapping(soft value)RxFigure 4-36Concatenated Reed Solomon and convolutional code– If the total number of K bytes is smaller than 239 bytes, the remaining 239 – Kbytes are filled by zero bytes. Systematic RS (255, 239, t = 8) coding is applied.After RS coding, the systematic structure of the RS code allows one to shortenthe code, i.e. remove the filled 239 – K zero bytes before transmission. Then, eachcoded packet of length K + 16 bytes will be serial bit converted.