Gallager Bounds for Noncoherent Decoders in Fading Channels
Gallager Bounds for Noncoherent Decoders in Fading Channels
复制标题
DOI：
10.1109/tit.2007.909071
复制
发表时间：
2007-12
影响因子：
2.5
通讯作者：
Cong Ling;Xiaofu Wu;K. H. Li;A. Kot
中科院分区：
文献类型：
--
作者：
Cong Ling;Xiaofu Wu;K. H. Li;A. Kot
最近，Gallager的边界技术已被用来推导出严格的性能边界的编码系统在衰落信道中。迄今为止，该领域的大多数作品都涉及相干解码。本文研究了衰落信道中非相干系统的Gallager界。与相干解码不同，以衰落系数为条件的非相干解码器/检测器的精确错误概率不允许封闭形式的表达式。本文通过采用自适应滤波技术克服了这一困难。虽然它在一定程度上削弱了界限，但在非相干衰落信道下，该技术使平均前限（LBA）界限和Gallager界限的推导成为封闭形式。数值算例表明，所提出的界是收敛的，并且比传统的联合界更紧。
Recently, Gallager's bounding techniques have been used to derive tight performance bounds for coded systems in fading channels. Most works in this field have thus far dealt with coherent decoding. This paper develops Gallager bounds for noncoherent systems in fading channels. Unlike coherent decoding, the exact error probability of a noncoherent decoder/detector conditioned on the fading coefficients does not admit a closed-form expression. This difficulty is overcome in this paper by employing the Chernoff technique. Although it weakens the bounds to some extent, the Chernoff technique enables the derivations of the limit-before-average (LBA) bound and Gallager bounds in closed form for noncoherent fading channels. Numerical examples show that the proposed bounds are convergent and are tighter than the conventional union bound.