Joint iterative decoding for pragmatic irregular LDPC-coded multi-relay cooperations

Abstract

In this article, a new kind of pragmatic simple-encoding irregular systematic lowdensity parity-check (LDPC) code for multi-relay coded cooperation is designed, where the introduced joint iterative decoding is performed in the destination based on a proposed joint Tanner graph for all the constituent LDPC codes used by the source and relays in multi-relay cooperation. The theoretical analysis and numerical results show that the coded cooperations outperform the coded noncooperation under the same code rate, and also achieve a good trade-off between the performance and the decoding complexity associated with the number of relays. This performance gain can be credited to the additional exchange of extrinsic information from the LDPC codes used by the source and the relays in both ideal and non-ideal cooperations.

A Deterministic Construction for Jointly Designed Quasicyclic LDPC Coded-Relay Cooperation

“…A general joint triple-layer Tanner graph used in one-relay coded cooperative system realizing source and relay nodes by two distinct QC-LDPC codes C (1) and C (2) is shown in Figure 2. In one relay cooperation, the overall code rate is R result � R 1 R 2 [13], where R 1 and R 2 denote the code rates of C (1) and C (2) , respectively. In particular, the resultant parity-check matrix…”

“…In coded relay cooperative communication, each relay node instead of transmitting the whole data frame only sends the redundant parity bits to the destination node. e performance of coded cooperation has been investigated based on turbo and LDPC codes [9][10][11][12][13][14]. However, LDPC-coded cooperation provides more advantages over turbo-coded cooperation in terms of low-cost decoding and delay for hardware implementation of the decoder.…”

Network‐coding‐based multisource multirelay LDPC‐coded cooperative MIMO

“…Assume that the numbers of sources and relays are large enough in the network-coding-based coded cooperative MIMO. We employ the law of large numbers to achieve the instantaneous channel capacity as Equation (25). Figure 6 shows that the instantaneous channel capacity increases as the number of receiving antennas increases.…”

“…However, if the links between sources and relays are not error free in a practical system, the relays still operate all the estimated codewords including the incorrectly estimated ones by XOR operator. It would inevitably result in error propagation, which decreases the bit error rate (BER) performance of the investigated cooperative MIMO and results in a serious error floor in the destination . In this case, the relays discard the incorrectly estimated codewords and operate only the correctly estimated ones by XOR operator.…”

Joint design of QC-LDPC codes for coded cooperation system with joint iterative decoding

“…It greatly reduces the implementation complexity without much degradation in decoding performance, and it is much easier to be implemented in the hardware. We employ the joint "Min-Sum" iterative decoding (Yang, Chen, Zong, Zhang, & Zhang, 2011;Zhang et al 2013a;Zhang, Yang, Tang, & Maharaj, 2013b) based on the bilayer Tanner graph, which is associated with double QC-LDPC codes used by the source and relay.…”