Precoding method comprising direct transmission link in multi-user bidirectional MIMO relay system

Abstract

The invention provides a precoding method comprising a direct transmission link in a multi-user bidirectional MIMO relay system, and belongs to the technical field of wireless relay communication. Theinvention provides a precoding design scheme comprising a direct transmission link between an information source and multiple users based on a complete channel in view of a bidirectional relay communication system in a half-duplex mode, and a relay precoding matrix is optimized by QR decomposition; the optimization of a user precoding matrix is based on MSMSE, an optimization objective equation is established, and the optimization problem is converted into a QCQP problem for optimization; the optimization of a client receiving filter matrix is to directly solve optimal expressions of an information source end and the client by using a partial derivative method; and finally, the user precoding matrix and the receiving filter matrix are jointly iterated to convergence to obtain an optimal precoding matrix. In the method, the contribution of the direct transmission link to the system is considered, and the performance of the system can be effectively improved.

Description

technical field [0001] The invention belongs to the technical field of wireless relay communication, and in particular relates to a precoding method including a direct transmission link under a multi-user two-way MIMO relay system. Background technique [0002] Due to the potential high rate and large capacity of the multiple-input multiple-output (MIMO) system, it has attracted widespread attention and has become a key technology for future mobile communication systems. Since the European Union launched the "5G NOW" project, countries around the world have stepped up research on 5G communication technology. my country has also added the research work of 5G communication technology to the "863" plan, the key technology of which is MIMO technology. MIMO technology is a communication technology method that does not need to increase the wireless frequency bandwidth, but can provide the same gain effect as increasing the bandwidth, and the relay communication technology can imp...

AI Technical Summary

Problems solved by technology

[0003] Most of the published literature on point-to-multipoint MIMO relay communication ignores the direct links from the source to all users. However, in practical systems, no matter whether it is uplink or downlink, direct links exists, and its contribution cannot be ignored

Literature Sun Q, Li L. Weighted Sum Rate Maximization for Downlink Multiuser Relay Network with Direct Link [J]. Wireless Personal Communications, 2014, 75(1): 369-384. Researched the joint prediction of unidirectional transmission including direct link coding, but its research is only a simple downlink, and the implementation complexity is high

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