近年來，人們對於快速、高效率通訊服務的需求逐漸增加，高速數據傳輸在未來通訊技術發展中佔有非常重要的地位。如何在遙遠的兩地間實現快速交換訊息並確保其正確性是下一代通訊技術的設計必須慎重考慮的。正交分頻多工(OFDM)由於具備較高的頻譜效率和抵抗多路徑干擾的能力成為目前解決高速數據傳輸的主流技術之一，然而OFDM系統具有峰值平均功率比(PAPR)過高的問題，過高的PAPR會導致非線性失真，增加功率放大器的設計難度。因此本論文採用同樣具備上述優勢但PAPR相對較低的單載波系統來進行錯誤率和複雜度的分析。首先我們會介紹單載波系統的調變解調流程和梯度搜尋演算法的理論基礎，接著會探討結合梯度搜尋演算法後對單載波系統錯誤率和複雜度的影響。最後透過模擬結果佐證梯度搜尋演算法能有效改善單載波區塊傳輸偵測的錯誤率。

In recent years, the demand for fast and efficient communication services has been steadily increasing. High-speed data transmission plays an important role in the develop-ment of future communication technologies. Ensuring rapid information exchange over long distances while maintaining accuracy is a critical consideration in the design of next-generation communication systems.
Orthogonal Frequency Division Multiplexing (OFDM) has become one of the main-stream technologies for high-speed data transmission due to its high spectral efficiency and robustness against multipath interference. However, OFDM systems suffer from a high Peak-to-Average Power Ratio (PAPR), which can cause nonlinear distortion and increase the complexity of power amplifier design.
Therefore, this thesis adopts a single-carrier system, which offers the same advantages while maintaining a relatively lower PAPR, to analyze error rates and system complexity. We first introduce the modulation and demodulation processes of single-carrier systems along with the theoretical foundation of the gradient search algorithm. We then examine the impact of integrating the gradient search algorithm on the error rate and complexity of single-carrier systems. Finally, simulation results are provided to demonstrate that the gra-dient search algorithm can effectively improve the error rate performance in single-carrier block transmission detection.

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