MIMO通信系统中基于星座扩展的脏纸预编码方法

预编码技术是提高多输入多输出(muhiple-input multiple-output,MIMO)无线系统容量的有效措施,提出了一种基于星座扩展的脏纸编码(dirty paper coding,DPC)方法,通过结合网格编码方法中的分集思想,在编码过程中加入星座扩展,利用大星座图冗余编码比特,能够在不消耗额外系统带宽的基础上实现系统容量提升.在发射信号相对应的扩展星座子集中寻找与归一化噪声最接近的星座点,将该星座点与归一化噪声的差值作为编码信号.该方法可以避免THP(Tomlinson-Harashima precoding)在对称取模过程中带来的性能损失,尤其是在低信噪比环境中.通过链路仿真,验证了基于星座扩展的DPC方法具有实现复杂度低、能够和相移键控调制技术相结合、提升系统容量的优点.

DPC approach based on constellation extension for MIMO wireless communication systems

Precoding technology is to improve the capacity of multiple input multiple output (MIMO) wireless systems of effective measures. This paper proposes a dirty paper coding (DPC) based on the constellation extension method, by combining grid coding method of diversity of ideas, to join the constellation extension in the encoding process,using big star redundancy coding bits,so that they need not consume extra bandwidth capacity improvement based on the implementation system.In this paper,the corresponding extend constellation subset and normalized noise for the closest constellation points is adopted, then the constellation points and normalized difference are found as a coded signal noise. This kind of treatment method can avoid THP in symmetric modulus in the process of the performance loss. Especially in low SNR environment, symmetrical modulus magnified greatly influenced by the noise of the system, the joint constellation extension DPC can avoid this. Verified by link simulation, this paper proposes constellation extension of the DPC has low implementation complexity, with the method of phase shift keying modulation technology, and promotes the combination of the advantages of the system capacity.