提出了一种有限反馈下多用户MIMO下行链路中用户调度和预编码的联合设计方法。在该方法中,每个用户向基站反馈自己希望的预编码向量序号,以及量化误差和自己信道的最大奇异值这两个标量。基站根据估计的信干噪比,选取信干噪比最大的一个用户,利用该用户反馈的预编码向量来生成一个预编码矩阵。基站继续逐个地选择其他用户,选择的准则是用户的信道能更好地匹配这个生成的预编码矩阵中的向量。该方法同时解决了多用户MIMO系统中,用户调度和预编码向量的设计这两个问题,属于一种跨层设计。仿真结果验证了所提方法的有效性。
A joint user pairing and precoding scheme in MU-MIMO broadcast channel with limited feedback is proposed.In the proposed scheme,each user feeds back its preferable precoding vector index and two scalars denoting quantization error and the largest singular value of channel matrix respectively.Base Station(BS) selects the first user who has highest estimated SINR,and generates a unitary precoding matrix based on the first user's preferred precoding vector.BS selects users whose channel can match the precoding vector in the generated matrix well.Numerical results verify the effectiveness of the proposed cross-layer design.