A Note on the Linear Programming Decoding of Binary Linear Codes for MultipleAccess Channel
Access this Article
Search this Article
Author(s)
Abstract
In this paper, we develop linearprogramming (LP) decoding for multipleaccess channels with binary linear codes. For singleuser channels, LP decoding has attracted much attention in recent years as a good approximation to maximumlikelihood (ML) decoding. We demonstrate how the ML decoding problem for multipleaccess channels with binary linear codes can be formulated as an LP problem. This is not straightforward, because the objective function of the problem is generally a nonlinear function of the codeword symbols. We introduce auxiliary variables such that the objective function is a linear function of these variables. The ML decoding problem then reduces to the LP problem. As in the case for singleuser channels, we formulate the relaxed LP problem to reduce the complexity for practical implementation, and as a result propose a decoder that has the desirable property known as the ML certificate property (i.e., if the decoder outputs an integer solution, the solution is guaranteed to be the ML codeword). Although the computational complexity of the proposed algorithm is exponential in the number of users, we can reduce this complexity for Gaussian multipleaccess channels. Furthermore, we compare the performance of the proposed decoder with a decoder based on the sumproduct algorithm.
Journal

 IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences 94(6), 12301237, 20110601
The Institute of Electronics, Information and Communication Engineers