V. Sorokine et al., Gallager codes for CDMA applications - Part II: Implementations, complexity, and system capacity, IEEE COMMUN, 48(11), 2000, pp. 1818-1828
We focus our attention on Gallager codes with parameters compatible with th
e IS-95 cellular radio standard. We discuss low complexity software and har
dware implementations of an iterative decoder for {N, -, 3} 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 sy
stem can be achieved, equivalent to a factor of two improvement relative to
state-of-the art orthogonal convolutional codes. Simulation results demons
trate the good performance of short-frame Gallager codes in the additive wh
ite Gaussian noise and certain fading channels.