建構一個編碼率二之差分空時碼

Abstract

本篇論文提出了一個編碼率二之差分空時碼，並且可應用於四根與八根傳送端天線數。除此之外，我們也推導出成對錯誤機率(pairwise error probability，簡稱PEP) 的上界，它提供了一個針對差分空時碼可達到之多樣性增益的理論驗證方法。我們的數學結果顯示出差分空時碼可得到的多樣性增益等同於距離矩陣的秩數與接收端天線個數M的乘積。透過使用成對錯誤機率，我們提出一個用來設計在這篇論文所提出之編碼率二，分別使用四根以及八根傳送端天線之差分空時碼之秩準則。從實驗模擬也顯示出我們所提出編碼率二之架構與透過成對錯誤機率所推導出來的分析結果符合，並且這些分別使用四根與八根傳送端天線之編碼率二之差分空時碼皆可得到多樣性增益四。

A rate-two differential space-time code (DSTC) is proposed in this work and is applicable to four and eight transmit antennas. Moreover, the upper bound of the pairwise error probability (PEP) is also investigated herein, providing a theoretical justification for the achievable diversity order of the proposed DSTC scheme. With the assumption of a full rank data matrix, the derivation results show that the diversity order equals to the rank of the distance matrix multiplied by the number of receive antennas M. Based on this PEP expression, we provide a rank criterion on the design of the rate-two DSTC. The simulation results match the analysis obtained from the PEP, and achieve the diversity order of four for four and eight transmit antennas respectively.