时变非整数非均匀码书

A Time-Varying Nonintegral Codebook with Nonuniform Quantization

针对空间相关信道下的预编码码书设计问题,提出了接近工程实现的时变非整数非均匀码书,并提出了码书周期的概念,提供了等效码书大小和预编码性能之间的多种折中方案,统一了自适应非均匀码书和固定均匀码书.在码书周期较短时,即使空间相关系数估计不正确,选中的码书仍包括当前最优的预编码矩阵,时变码书近似等效为一个较大的固定码书.当信道的空间相关特征变化较快时,可使用较小的码书周期以保证时变码书的跟踪特性.

The precoding codebook design with the spatial-correlated channel is investigated.Termed as time-varying nonintegral codebook,a codebook scheme is presented for practical implementation.The concept of codebook period is also proposed.The time-varying nonintegral codebook supports various trade-off options between the codebook size and the system capacity performance.It also includes the traditional fixed uniform codebook as a special mode.If the codebook period is small,the estimation of the spatial correlation coefficient seems not accurate enough.However,the chosen codebook includes the best precoding matrix,i.e.the time-varying nonintegral codebook performs similarly as a traditional fixed codebook with larger size.If the spatial correlation coefficient changes fast,the codebook period will be decreased to guarantee that the codebook can trace the varying channel.