混合精度ADC系统中极化码编译码优化研究

在大规模MIMO系统中，为降低射频链路能耗以及提高后续基带系统的运算效率，混合精度ADC（mixed-ADC）架构被提出。混合精度ADC的出现，使得极化码（polar code)的编码构造基础被改变：不同的ADC精度，对应着不同的底层信道，导致传统的基于相同底层信道的极化码构造方案不再适用。同时，鉴于目前极化码译码器至少使用四比特实现的情况，在混合精度ADC模式下，低精度ADC的存在，会对极化码的译码性能带来很大影响。因此，本项目拟研究在混合ADC架构下，极化码编码构造的新方案，各主流译码方案在混合精度ADC场景下的性能，以及编码构造及译码方案所需的相应的ADC优化方案；同时，本项目拟将ADC精度配置、极化码编码构造、极化码译码、信道估计进行联合优化，以获得最优系统性能。本项目的研究，将为极化码更加广泛的应用提供理论及实现基础。

In　massive　multiple-input multiple-output (MIMO)　systems, mixed-ADC schemes are proposed to reduce the energy consumption in RF links and to improve　the efficiency of　the subsequent baseband processing.　In　Mixed-ADC scenarios,　the basic principle of the construction of polar codes is on longer valid:　the underlying channels are not the same as the original polar codes, as they come from different ADCs with different precisions. In the meantime, the decoding performance of polar codes will also be greatly affected by the low-precision ADCs, seen from the fact that at least four bits are employed in the current implementations of polar codes.　In this project, we are going to study the effect and the corresponding improvement of construction and decoding of polar codes in the mixed-ADC scenarios. The iterative optimization will also be performed on the mixed-ADC module, the polar code construction, the decoding, and the channel estimation to yield the best possible system performance in the mixed-ADC channel. The results in the project can provide fundamental theoretical and implementation support for polar codes to be applied in more general cases.