多用户空间复用OFDM系统中的子载波分配

Adaptive subcarrier allocation for spatial multiplexing-based multiuser OFDM-systems

以系统瞬时容量最大化为目标,提出了两类基于空间复用的下行多用户OFDM系统中的自适应子载波分配准则:a.将每个OFDM子载波分配给一个用户的“独占准则”;b.允许多个用户共享同一个子载波的“共享准则”.分析和仿真表明,两类分配准则都能有效获取系统中的“多用户分集”,明显提高MIMO-OFDM系统的容量.此外,通过实验比较还发现,相对于“共享”分配,“独占”的分配方式能够更好地达到容量提升、反馈开销和复杂度等方面的折衷,是一种实际可行的方案.

In consideration of maximizing the instantaneous capacity, two categories criteria for subcartier assignment downline spatial multiplexing based OFDM systems was proposed. They were the exclusive criteria and the shared one. The previous one allocated each subcarrier to a single user and the later one allowed multiple users to occupy a subcarrier. Simulation demonstrated that both the criteria were capable of utilizing the multiuser diversity to enhance the capacity of MIMO-OFDM systems. In comparison with shared allocation, the exclusive allocation can reach tradeoff in capacity enhancement, overhead and complexity. It was a feasible scheme for wireless communication system.