利用中繼站做差分式時空碼傳輸

Abstract

本論文的目的是探討如何在無線中繼式網路使用解調時不需要通道估測的差分式時空碼傳輸。MIMO（Multi-Input Multi-Output）系統中我們可以利用時空碼在傳送端與接收端藉由多根天線傳送資訊來增加傳輸容量以及可靠度，但在傳送時空碼時必須作通道估測才能在接收端正確的解碼，而無線中繼式網路傳送資訊時因為進行兩階端傳輸，比起在MIMO系統中使用時空碼時需要更大量的通道估測才能在接收端解碼。為了減少通道估測量我們將不需要通道估測就能解調的差分式時空碼應用在無線中繼式網路上，並利用雙層編碼的設計讓各個中繼端皆使用單一天線合作傳送一組差分式時空碼，同時讓接收端在無通道估測的情形下藉由前後時間點收到的訊息解出傳送資訊。最後我們將探討在不同的中繼式通訊規則下產生的各種差分式時空碼傳輸，並比較各種模式在傳輸錯誤率上的表現。

This thesis is focused on how to use differential space time code transmission on wireless relay network and decode data with no channel estimation. In MIMO（Multi-Input Multi-Output）system, we can transmit space time code to improve transmission capacity and reliability with multiple antennas at transmitter and receiver, and we need channel estimation for correct decoding at receiver. Because of two-phase transmission on wireless relay network, it will need more channel estimation results than MIMO system. For decreasing the amount of channel estimation, we implement differential space time code on wireless relay network and use the design of double-coding to cooperatively transmit differential space time code at all relays which uses one antenna. The receiver will decode transmitted data by the received signal and past received signal with no channel estimation. Finally, we will discuss all differential transmissions through different relaying protocol and compare the performance of all differential transmission models by bit error rate.