OFDMA, Orthogonal Frequency Division Multiple Access is a broad band communication method. Here channel estimation is more crucial. Based on the FFT size used for OFDM transmission method that many number of channel co-efficients are to be estimated

光纤射频传输系统中相干正交频分复用的研究，介绍了系统的结构和性能,是一份很不错的学习材料。-Coherent optical fiber radio transmission system using orthogonal frequency division multiplexing, introduces the system structure and performance, is a very good learning materials.