COMMUNICATION SYSTEM USING OFDM

摘要

A wireless OFDM communications data packet network wherein, each transmitter includes a transmit modulator to append a repeated pseudo random binary sequence pilot symbol to the start of each data packet, a serial/parallel multiplexer, a frequency to time domain inverse FFT converter, a greater than the nominal rate up-sampler, a LPF, a D/A converter, and an RF modulator. Each receiver includes an RF de-modulator, a greater than the nominal rate A/D converter, a LPF, a down-sampler to reduce the sampling rate to the nominal rate, a significant pilot symbols frame detector that makes initial estimates of at least one parameter, a PLL removes estimated frequency and phase offsets, a time to frequency domain FFT converter, a linear phase corrector to remove estimated sub-sample timing errors, a decision block to decide to which allowable data point each bit is assigned to produce noise free data, and a parallel/serial de-multiplexer.