OFDM Systems for Wireless Communications (Paperback)

Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in the standards for digital audio/video broadcasting, WiFi and WiMax. Being a frequency-domain approach to communications, OFDM has important advantages in dealing with the frequency-selective nature of high data rate wireless communication channels. As the needs for operating with higher data rates become more pressing, OFDM systems have emerged as an effective physical-layer solution. This short monograph is intended as a tutorial which highlights the deleterious aspects of the wireless channel and presents why OFDM is a good choice as a modulation that can transmit at high data rates. The system-level approach we shall pursue will also point out the disadvantages of OFDM systems especially in the context of peak to average ratio, and carrier frequency synchronization. Finally, simulation of OFDM systems will be given due prominence. Simple MATLAB programs are provided for bit error rate simulation using a discrete-time OFDM representation. Software is also provided to simulate the effects of inter-block-interference, inter-carrier-interference and signal clipping on the error rate performance. Different components of the OFDM system are described, and detailed implementation notes are provided for the programs. The program can be downloaded here. Table of Contents: Introduction / Modeling Wireless Channels / Baseband OFDM System / Carrier Frequency Offset / Peak to Average Power Ratio / Simulation of the Performance of OFDM Systems / Conclusions

正交分頻多工（Orthogonal Frequency Division Multiplexing，OFDM）系統廣泛應用於數字音頻/視頻廣播、WiFi和WiMax標準中。作為一種頻域通信方法，OFDM在處理高數據速率無線通信通道的頻率選擇性特性方面具有重要優勢。隨著對更高數據速率操作需求的增加，OFDM系統已成為一種有效的物理層解決方案。

本短篇專著旨在作為一個教程，突出無線通道的不利因素，並解釋為什麼OFDM是一個能夠以高數據速率傳輸的調變方式的良好選擇。我們將採用系統級方法，同時指出OFDM系統的缺點，特別是在峰值與平均功率比和載波頻率同步方面。最後，將重點介紹OFDM系統的模擬。提供了使用離散時間OFDM表示進行位錯誤率模擬的簡單MATLAB程序。還提供了用於模擬區塊間干擾、載波間干擾和信號剪切對錯誤率性能的影響的軟件。描述了OFDM系統的不同組件，並提供了程序的詳細實施注意事項。可以在此處下載該程序。

目錄：引言/建模無線通道/基帶OFDM系統/載波頻率偏移/峰值與平均功率比/OFDM系統性能模擬/結論