论文标题
在有限的区块长度中的高斯多重和随机访问
Gaussian Multiple and Random Access in the Finite Blocklength Regime
论文作者
论文摘要
本文介绍了高斯多访问通道（MAC）和随机访问通道（RAC）（在平均率和最大功率约束下）的有限宽大可实现性界限。 Using random codewords uniformly distributed on a sphere and a maximum likelihood decoder, the derived MAC bound on each transmitter's rate matches the MolavianJazi-Laneman bound (2015) in its first- and second-order terms, improving the remaining terms to $\frac12\frac{\log n}{n}+O \left(\frac 1 n \right)$ bits per channel 使用。然后，结果扩展到RAC模型，在该模型中，编码器和解码器都不知道$ k $可能的发射器处于活动状态。在拟议的无额定编码策略中，解码是在一次$ n_t $的时间发生，这取决于解码器的估算值$ t $ t $ t $ t $ t $ t $ t $。在每个潜在解码时间$ n_i $，$ i \ leq t $的单位反馈到所有编码器的单位反馈，请告知编码器何时停止传输。对于此RAC模型，提议的代码获得了与正在运行的高斯Mac最著名的结果相同的一阶，二阶和三阶性能。
This paper presents finite-blocklength achievability bounds for the Gaussian multiple access channel (MAC) and random access channel (RAC) under average-error and maximal-power constraints. Using random codewords uniformly distributed on a sphere and a maximum likelihood decoder, the derived MAC bound on each transmitter's rate matches the MolavianJazi-Laneman bound (2015) in its first- and second-order terms, improving the remaining terms to $\frac12\frac{\log n}{n}+O \left(\frac 1 n \right)$ bits per channel use. The result then extends to a RAC model in which neither the encoders nor the decoder knows which of $K$ possible transmitters are active. In the proposed rateless coding strategy, decoding occurs at a time $n_t$ that depends on the decoder's estimate $t$ of the number of active transmitters $k$. Single-bit feedback from the decoder to all encoders at each potential decoding time $n_i$, $i \leq t$, informs the encoders when to stop transmitting. For this RAC model, the proposed code achieves the same first-, second-, and third-order performance as the best known result for the Gaussian MAC in operation.
