Title :
Trellis decoding of linear block codes in digital mobile radio
Author :
Matsumoto, Tadashi
Author_Institution :
Radio Commun. Syst. Lab., NTT, Yokosuka, Japan
Abstract :
Word error rate (WER) performance with soft decision decoding of linear block codes using a trellis is investigated for noncoherent FSK (frequency-shift keying) in a Rayleigh fading channel. The received signal envelopes corresponding to each bit of the code are sampled and used for estimating reliability of the bits. Hamming (7,4) code is used for WER performance evaluation by means of computer simulation and laboratory experiments. The simulation results show that required SNR to obtain a WER of 10-3 for trellis decoding is about 5 dB lower than that for minimum distance decoding with 1-bit error correction when (maximum Doppler frequency)×(bit interleaving degree)/(bit rate) ⩾0.2. The effect of n-bit analog-to-digital conversion in signal envelope sampling is also investigated. A simplified trellis decoding algorithm, in which the hard decision output of a bit with the envelope sample greater than the threshold value is accepted as correct, is presented for complexity reduction
Keywords :
decoding; digital simulation; error correction codes; frequency shift keying; mobile radio systems; Hamming code; Rayleigh fading channel; computer simulation; digital mobile radio; frequency-shift keying; hard decision output; laboratory experiments; linear block codes; n-bit analog-to-digital conversion; noncoherent FSK; performance evaluation; signal envelope sampling; soft decision decoding; threshold value; trellis decoding; Block codes; Computational modeling; Computer simulation; Decoding; Error analysis; Error correction; Fading; Frequency shift keying; Laboratories; Land mobile radio;
Conference_Titel :
Vehicular Technology Conference, 1988, IEEE 38th
Conference_Location :
Philadelphia, PA
DOI :
10.1109/VETEC.1988.195328
