即時基頻正交分頻多工解調

Abstract

由於抗時間延遲跟多路徑免疫,抵抗頻率選擇性衰減以及有效的頻寬 使用率等特性,正交分頻多工(OFDM)技術在近年來受到廣泛的重視,然而 大多數的這方面研究依然停留在離線(offline)訊號處理,這種處理方式 不僅無法做長時間的系統效能驗證亦不考慮實際硬體上的限制,因此,對 於驗證正交分頻多工(OFDM)技術在實際實現(implementation)的可行性 上,發展即時的正交分頻多工(OFDM)演算法是必要的。 在本論文中,我們實現了一個 157.5M bit/s data rate 即時正交分 頻多工存取解調系統,這個系統有90 MHz 的throughput,經過硬體的協同 仿真,我們證明我們的正交分頻多工存取解調系統在實際硬體上是可行的。 此外,我們亦成功地利用FPGA 對我們採用的ADC(ADC083000)作配置並使它 正確地工作。

Due to immunity to delay spread and multipath, resistance to frequency select fading and efficient bandwidth usage, OFDM (Orthogonal Frequency Division Multiplexing) techniques are taken seriously in recent years. However, most of these researches are demonstrated by offline processing which doesn’t allow long-term performance verification and also doesn't consider the limitation of practical hardware. Therefore, evaluating real-time OFDM algorithm is necessary for validating its feasibility in practical. implementation. In this work, we have realized a 157.5M bit/s data rate real time OFDM demodulation system with 90MHz throughput. After hardware co-simulation, we confirm that our OFDM demodulation system is feasible in practical implementation. In addition, we also have successfully configured ADC083000 which we adopted ADC through FPGA and make it work correctly.