分增益多重存取及高密度簽名碼分碼多重存取在 隨機存取通道中的應用

The application of GDMA and HDS-CDMA to Random Access Channel

陳逸樺(Yi-Hua Chen)

指導教授 ： 林茂昭

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2023年)

https://doi.org/10.6342/NTU202302588

摘要

分增益多重存取技術是一種基於增益的非正交多重存取方法。多個用戶可以同時在同一資源中進行傳送，並透過各個用戶獨立的通道係數來達到多重存取的效果。

本篇論文也提到了近年來被廣泛研究的低密度簽名碼分碼多重存取以及近期所提出的高密度簽名碼分碼多重存取。我們探討了將以上幾種多重存取技術與錯誤更正碼,正交分頻多工結合來增加系統可靠度，並比較這些系統的性能表現。

同時我們也探討了其他文獻所提出的基於分群演算法通道估測技術結合以上的系統，並且進一步提供了半盲測通道估測技術來提高系統的性能。

隨機接取是無線通訊中很重要的一部份，我們根據先前文獻所提出一種透過分增益多重存取技術結合ALOHA的系統進行調整，把分增益多重存取技術改成高密度簽名碼分碼多重存取技術，並以不同的調變方式及不同通道估測演算法來比較各個系統的性能。

關鍵字

多重存取 ； 錯誤更正碼 ； 正交分頻多工 ； 通道估測 ； 隨機存取 ； 低密度簽記 ； 盲測演算法

並列摘要

Gain-division multiple access (GDMA) is a gain-based non-orthogonal multiple access (NOMA) technique where multiple users can simultaneously transmit their messages within the same resource. It achieves multiple access by utilizing independent channel coefficients for each user.

This thesis reviews the widely studied Low-Density Signature Code Division Multiple Access (LDS-CDMA) and a recently proposed High-Density Signature Code Division Multiple Access (HDS-CDMA) techniques. We investigate the performances of integrating these multiple access techniques with error correction codes and Orthogonal Frequency Division Multiplexing (OFDM).

We also investigate the incorporation of channel estimation techniques based on clustering algorithms proposed in other literature into our systems. A semi-blind channel estimation technique is then provided so as to improve system performance.

Random access is an essential part in wireless communication. In a recent work, GDMA assisted ALOHA protocol method has been proposed. We replace GDMA system with HDS-CDMA system in the slotted ALOHA system and compare the performance of different systems under different modulation levels and different channel estimation algorithms.

並列關鍵字

Multiple Access ； Error Correcting Code ； Orthogonal Frequency Division Multiplexing ； Channel Estimation ； Random Access ； Low-Density Signature ； Blindly Estimate Algorithm

參考文獻

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