Performance Of Linear Block Codes Research Articles

Performance of Linear Block Coding for Multipath Fading Channel

This paper deals with the performance of linear block codes which provide a new paradigm for transmission over multipath fading channels. Multi path channel fading is the main enemy for any wireless communications system. Therefore, for any novel approach applied at any wireless communication system, its efficiency is measured according to its ability of mitigating the distortion caused by fading. It causes time dispersion to the transmitted symbols resulting in inter symbol interference (ISI). ISI inter symbol interference problem is a major impairment of the wireless communication channel. To mitigate the ISI problem and to have reliable communications in wireless channel, channel equalizer and channel coding technique is often employed. In this paper the BER (Bit Error Rate) performance is shown from analytically and by means of simulation for multipath dispersive channels. We have designed a channel equalizer using MLSE (Viterbi algorithm) in this paper for such a multipath channel (introducing inter symbol interferences) with BPSK modulation based on the assumption that the channel can be perfectly estimated at the receiver. Obviously the performance of channel coding in terms of BER is better than uncoded channel. Index Terms—BER, BPSK, Linear block code, SNR, Viterbi algorithm, Maximum-likelihood sequence estimator (MLSE), ISI.

Performance of Linear Block Codes Concatenated with Differential PSK

In this letter we investigate the bit and frame error rate performance of various linear block codes when concatenated with a differential phase shift keying modulator. The codes considered include single parity check, Hamming and product codes. We find block codes which significantly improve the frame error rate performance over previous results. An EXIT chart analysis is included.

On the weight distribution of linear block codes formed from convolutional codes

We explain how to obtain the weight enumerator and the performance of linear block codes formed in several distinct ways from a convolutional code.

Decoding performance of linear block codes using a trellis in digital mobile radio

Trellis decoding of linear block codes in a Rayleigh fading channel is discussed. Two methods for calculating metric values for each bit in a received block are considered: the values are calculated from the received signal envelope sample and from the demodulator output. Bit error rate (BER) performances of hard decision and trellis decoding are compared using Hamming (7, 4) and Golay (24, 12) codes in computer simulations and laboratory experiments. A simplified trellis decoding algorithm, in which the hard decision output of a bit with an envelope sample greater than the threshold value is accepted as correct, is presented. Laboratory experimental results for trellis decoding in combination with Gaussian minimum-shift-keying (GMSK) modulation and frequency detection are shown. The effect of n-bit A/D-conversion in signal envelope sampling is investigated experimentally. The results show that the trellis decoding algorithm improves BER performance. >