多用户MIMO网络的OFDM放大转发双向中继策略

OFDM Amplify-and-Forward Two-Way Relaying for Multiuser MIMO Networks

在多用户MIMO通信网络中,该文提出一种新的放大转发双向中继策略,在第1时隙的多址传输中采用OFDMA,在第2时隙的广播传输中采用OFDM/SDMA,通过利用频率分集和空间分集提高了系统性能。针对双向中继传输的特点,采用两种方法在每个子载波上设计了中继波束形成矩阵,即信漏噪比(SLNR)准则和块对角化迫零(BDZF)准则。利用割集理论推导了该双向中继网络的容量域上界。仿真结论表明,所提出的双向中继策略在系统和速率性能上优于其他3种中继策略,并能逼近所推导的容量域上界。

In multiuser MIMO communication networks,a new amplify-and-forward two-way relaying scheme is proposed employing OFDMA for the multiple access transmission in the first time slot and OFDM/SDMA for the broadcast transmission in the second time slot to improve the performance of the system through utilizing frequency diversity and spatial diversity.Considering the characteristic of two-way relaying,the relay beamforming matrixes are designed according to two methods respectively,i.e.,signal to leakage and noise ratio （SLNR） and block diagonalization based zero-forcing （BDZF）,on per subcarrier basis.The upper bound on the capacity region of this two-way relay network is also derived by using cut-set theory.Simulation results show that the proposed scheme outperforms three other two-way relaying schemes in terms of sum rate and can approach the upper bound of capacity region.