We study the problem of unsourced random access (URA) over Rayleigh block-fading channels with a receiver equipped with multiple antennas. We employ multiple stages of orthogonal pilots, each of which is randomly picked from a codebook. In the proposed scheme, each user encodes its message using a polar code and appends it to the selected pilot sequences to construct its transmitted signal. Accordingly, the received signal consists of superposition of the users' signals each composed of multiple orthogonal pilot parts and a polar coded part. We use an iterative approach for decoding the transmitted messages along with a suitable successive interference cancellation scheme. Performance of the proposed scheme is illustrated via extensive set of simulation results which show that it significantly outperforms the existing approaches for URA over multiple-input multiple-output fading channels.
翻译:我们研究了Rayleigh区块淡化通道上无源随机访问的问题,该通道上装有一台装有多天线的接收器。我们使用了多个阶段的正对实验,每个阶段都是从代码簿中随机选取的。在拟议的办法中,每个用户用极代码编码信息,并将其添加到选定的试验序列中,以构建其传输的信号。因此,收到的信号包括用户信号的叠加,每个信号由多个正方位试验部件和极地编码部分组成。我们使用迭接方法解码传送的信息,同时采用适当的连续取消干扰计划。通过广泛的模拟结果显示,拟议办法的绩效大大优于现有URA对多输出多输出排泄通道采用的方法。