LDGM Codes for Channel Coding and Joint Source-Channel Coding of Correlated Sources

Abstract

We propose a coding scheme based on the use of systematic linear codes with low-density generator matrix (LDGM codes) for channel coding and joint source-channel coding of multiterminal correlated binary sources. In both cases, the structures of the LDGM encoder and decoder are shown, and a concatenated scheme aimed at reducing the error floor is proposed. Several decoding possibilities are investigated, compared, and evaluated. For different types of noisy channels and correlation models, the resulting performance is very close to the theoretical limits

Optimizing channel coding for orthogonal multiple access schemes with correlated sources

“…The pdf of LLR y, j can eventually be computed according to (13), where the input messages {LLR x, j } are replaced by {LLR ′ x, j }. Note that, unlike the other messages, a ′ x (z) and a ′ y (z) are not assumed to be Gaussian and, thus, they are indicated explicitly in Fig.…”

“…However, implementing a practical system based on separation, i.e., distributed source coding, is not straightforward [8]- [11]. Moreover, the problem of designing good practical codes for correlated sources is still an open issue [12] and, moreover, separation between source and channel coding may lead to catastrophic error propagation [13]. Alternative approaches to distributed source coding are represented by cooperative source-channel coding schemes and joint source-channel coding (JSCC).…”

Iterative decoding for Noisy Network Coding for Two-Way Relay channels

“…The mapping from b to x r is found by a Joint Source Channel Code (JSCC) (see e.g. [10]): The binary quantizer output b is mapped 1 to a n r -bit codeword c r of the code C r . The binary code C r has a code rate R JSCC r = kr nr .…”

Impact of physical layer design on the deployment of a sensor network with correlated observations

“…In the first case and for distributed encoding, source channel separation holds [2], whereas it may not hold in the second case [5]. However, since there exists no practical distributed joint source channel coding schemes for more than 2 sources (for 2 sources see [13,8]), we assume separated source channel coding schemes. Therefore, for reliable communication, the set of rates and powers {R i , P i } should lie in the intersection of the Slepian Wolf region and of the capacity region.…”