Evaluation of Gallager Codes for Short Blo k Lengthand High Rate Appli

Evaluation of Gallager Codes for Short Block Length and High Rate Applications

Gallager Codes for High Rate Applications

Gallager codes with large block length and low rate (e.g., N ' 10, 000–40, 000, R ' 0.25–0.5) have been shown to have recordbreaking performance for low signal-to-noise applications. Gallager codes with high rates (R ' 0.8–0.94) are also excellent, outperforming comparable BCH and Reed-Solomon codes, even at short blocklength (N ' 2, 000–4, 000) (MacKay and Davey, 2000). This paper looks in mor...

Gallager codes for CDMA applications .I. Generalizations, constructions, and performance bounds

We focus on applications of low-rate Gallager (low-density parity-check) codes in code-division multiple-access schemes. The codes that we present here achieve good performance with relatively short frame-lengths in additive white Gaussian noise channels and, perhaps more importantly, in fading channels. These codes can be decoded with low complexity by using iterative decoding procedures. We p...

Gallager Codes for CDMA Applications—Part II: Implementations, Complexity, and System Capacity

We focus our attention on Gallager codes with parameters compatible with the IS-95 cellular radio standard. We discuss low complexity software and hardware implementations of an iterative decoder for fN; ; 3g Gallager codes. We estimate that by using Gallager codes, a factor of five improvement in the code-division multiple-access system capacity relative to an uncoded system can be achieved, e...

Gallager codes for CDMA applications. II. Implementations, complexity, and system capacity

We focus our attention on Gallager codes with parameters compatible with the IS-95 cellular radio standard. We discuss low complexity software and hardware implementations of an iterative decoder for fN; ; 3g Gallager codes. We estimate that by using Gallager codes, a factor of five improvement in the code-division multiple-access system capacity relative to an uncoded system can be achieved, e...