1. Techniques for Improving the Finite Length Performance of Sparse Superposition Codes.
- Author
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Greig, Adam and Venkataramanan, Ramji
- Subjects
- *
ADDITIVE white Gaussian noise channels , *IEEE 802.16 (Standard) , *APPROXIMATE solutions (Logic) , *DECODING algorithms , *SYSTEM analysis - Abstract
Sparse superposition codes are a recent class of codes introduced by Barron and Joseph for efficient communication over the AWGN channel. With an appropriate power allocation, these codes have been shown to be asymptotically capacity-achieving with computationally feasible decoding. However, a direct implementation of the capacity-achieving construction does not give good finite length error performance. In this paper, we consider sparse superposition codes with approximate message passing (AMP) decoding, and describe a variety of techniques to improve their finite length performance. These include an iterative algorithm for SPARC power allocation, guidelines for choosing codebook parameters, and estimating a critical decoding parameter online instead of precomputation. We also show how partial outer codes can be used in conjunction with AMP decoding to obtain a steep waterfall in the error performance curves. We compare the error performance of AMP-decoded sparse superposition codes with coded modulation using LDPC codes from the WiMAX standard. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
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