MMSE of “Bad” Codes
MMSE of “Bad” Codes
复制标题
“坏”代码的 MMSE
DOI:
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发表时间:
2011
影响因子:
2.5
通讯作者:
S. Shamai
中科院分区:
文献类型:
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作者:
R. Bustin;S. Shamai
We examine codes, over the additive Gaussian noise channel, designed for reliable communication at some specific signal-to-noise ratio (SNR) and constrained by the permitted minimum mean-square error (MMSE) at lower SNRs. The maximum possible rate is below point-to-point capacity, and hence, these are nonoptimal codes (alternatively referred to as “bad” codes). We show that the maximum possible rate is the one attained by superposition codebooks. Moreover, the MMSE and mutual information behavior as a function of SNR, for any code attaining the maximum rate under the MMSE constraint, is known for all SNR. We also provide a lower bound on the MMSE for finite length codes, as a function of the error probability of the code.