该文针对多中继MIMO通信系统多用户传输时的用户间干扰问题,提出了一种可以有效抑制多用户干扰的发射端与中继端迭代预编码的方案。该方案首先在中继端进行多中继联合的迫零预编码,然后将基站与多用户之间等效为一个点到多点的MIMO信道,采用最大化信漏噪比的预编码方法,在发射端进一步消除用户间的干扰,同时避免了噪声放大的影响,进而通过中继端预编码与发射端预编码的多次迭代,更好地保持了多中继并行传输引入空间分集所带来的性能优势,有效地抑制了用户间干扰,获得了更高的系统和容量。
In this paper, an iterative precoding method is proposed, which successively in turn optimizes the precoding matrix at base station or relay station for suppressing the multiuser interference of multiuser multi-relay MIMO system. Firstly, the multi-relay joint zero forcing precoding is adopted at relay station. Secondly, the channel between the base station and multiple users is taken as an equivalent point-to-multipoint MIMO channel, then the signal-to-leakage ratio precoding method at base station is used to further cancel inter-user interference and avoid the Influence of noise amplification. Furthermore, Multiple iterative precoding at relay stations and base station can maintain better space diversity introduced by parallel transmission of multiple relays, also can achieve higher sum capacity of system.