Park Sangjoon
Department of Electronic Engineering, Kyonggi University, Suwon 16227, Korea.
Sensors (Basel). 2021 May 27;21(11):3734. doi: 10.3390/s21113734.
In this paper, a QR-decomposition-based scheduled belief propagation (BP) detector with interference cancellation (IC) and candidate constraints is proposed for multiple-input multiple-output (MIMO) systems. Based on a bipartite graph generated from an upper triangular channel matrix following linear transformation using QR decomposition, the proposed detector performs a sequential message updating procedure between bit nodes. During this updating procedure, candidate constraints are imposed to restrict the number of possible candidate vectors for the calculation of observation-to-bit messages. In addition, after obtaining the soft message corresponding to the bit sequence in each transmit symbol, a hard-decision IC operation is performed to reduce the size of the bipartite graph and indirectly update the messages for the remaining symbols. Therefore, the proposed scheme provides a huge complexity reduction compared to conventional BP detectors that perform message updating by using all related messages directly. Simulation results confirm that the proposed detector can achieve suboptimum error performance with significantly improved convergence speed and reduced computational complexity compared to conventional BP detectors in MIMO systems.
本文针对多输入多输出（MIMO）系统，提出了一种基于QR分解的带干扰消除（IC）和候选约束的调度置信传播（BP）检测器。基于使用QR分解进行线性变换后从三角上信道矩阵生成的二分图，该检测器在位节点之间执行顺序消息更新过程。在该更新过程中，施加候选约束以限制用于计算观测到比特消息的可能候选向量的数量。此外，在获得每个发射符号中比特序列对应的软消息后，执行硬判决IC操作以减小二分图的大小，并间接更新其余符号的消息。因此，与直接使用所有相关消息进行消息更新的传统BP检测器相比，该方案大大降低了复杂度。仿真结果表明，与MIMO系统中的传统BP检测器相比，该检测器能够实现次优的错误性能，收敛速度显著提高，计算复杂度降低。
