統計特性及有限回饋位元配置在具相關性多輸入多輸出正交分頻多工系統之效能分析

Abstract

In this thesis, we evaluate two bit loading schemes for a MIMO-OFDM system over a channel that is correlated in time and space. For the first scheme, we assume there is a reverse link of low transmission rate so that the receiver can feedback quantized bit loading to the transmitter. We call this BAfb (feedback of bit loading) scheme. In the second scheme, a statistical bit loading is computed based on statistics of the channel. No feedback is necessary in this case. We call this BAstat (statistical bit loading) scheme. The simulation results show that, in general, BAfb scheme performs better than BAstat when the channels are highly correlated in time. When the channel is not so highly correlated in time, BAstat scheme performs better. Furthermore, performances of BAstat does not vary with the time and it is very useful for MIMO transmission with no feedback.

In this thesis, we evaluate two bit loading schemes for a MIMO-OFDM system over a channel that is correlated in time and space. For the first scheme, we assume there is a reverse link of low transmission rate so that the receiver can feedback quantized bit loading to the transmitter. We call this BAfb (feedback of bit loading) scheme. In the second scheme, a statistical bit loading is computed based on statistics of the channel. No feedback is necessary in this case. We call this BAstat (statistical bit loading) scheme. The simulation results show that, in general, BAfb scheme performs better than BAstat when the channels are highly correlated in time. When the channel is not so highly correlated in time, BAstat scheme performs better. Furthermore, performances of BAstat does not vary with the time and it is very useful for MIMO transmission with no feedback.