级联LDPC编码的协作MIMO系统研究

为满足无线传感器网络应用MIMO技术的需求,构建了基于分簇的协作MIMO系统,并对传输过程进行了分析.针对系统受发射端簇首节点与协作节点之间信道质量影响较大,存在误码传播的问题,设计了级联LDPC编码的协作MIMO系统,详细分析了接收端LDPC分层译码算法的实现过程.仿真了簇首节点与协作节点之间相同信噪比情况下不同天线数目的误码性能,簇首节点与协作节点之间不同信噪比情况下相同天线数目的系统性能和2发1收、2发2收级联LDPC编码的协作MIMO系统性能,可以推广到多发多收系统.仿真表明:级联LDPC编码的协作MIMO系统可以有效地解决协作MIMO系统误码传播的问题,显著的提高协作MIMO系统的性能.并且仿真中接收端采用的LDPC分层译码算法,在相同仿真条件下,与传统的BP译码算法相比,收敛速度更快,纠错性能更好.

The Research of Cooperative MIMO System Concatenated LDPC Coding

To meet the needs of wireless sensor network with MIMO technology, the cooperative MIMO system is built based on cluster and the transmission process is analyzed. To resolve the problem of error propagation caused by the transmission between the head node and the cooperative node in the same cluster, the cooperative MIMO system concatenated LDPC coding is designed and the realization process of layered decoding algorithm is analyzed in detail. The error performance under the same signal-to-noise ratio with different antenna number and the error performance of the different signal-to-noise ratio with same antenna number between the cluster head node and cooperative nodes are simulated. Besides, the performances of the cooperative MIMO system concatenated LDPC coding with two transmitters and one receiver, and with two transmitters and two receivers are simulated, which can be extended to system with multiple transmitters and multiple receivers. The simulation results show that the cascaded LDPC coding cooperative MIMO system can effectively solve the problem of error propagation in cooperative MIMO system. Meanwhile the LDPC layered decoding algorithm is used at the receiving end, compared with conventional BP decoding, in the same simulation conditions, convergence is faster and error correction performance is better.