Patent ID: 7706458

Claim:
An apparatus for synchronizing a communication system, the apparatus comprising: a number (Q) of Orthogonal Frequency Division Multiplexing (OFDM) modulators, each OFDM modulator producing a frame having at least one inserted symbol, a plurality of data symbols, and cyclic prefixes; Q transmitting antennas, each transmitting antenna connected to a respective OFDM modulator, the transmitting antennas configured to transmit a respective frame over a channel; a number (L) of receiving antennas for receiving the transmitted frames; and L OFDM demodulators, each OFDM demodulator corresponding to a respective receiving antenna, the L OFDM demodulators including a synchronization circuit that processes the received frame in order to synchronize the received frame in both time domain and frequency domain, wherein each of the L OFDM demodulators comprises: a pre-amplifier; a local oscillator; a mixer having a first input and a second input, the first input connected to an output of the pre-amplifier, the second input connected to an output of the local oscillator; an analog-to-digital converter (ADC) connected to an output of the mixer; the synchronization circuit having one input connected to an output of the ADC; a cyclic-prefix remover connected to an output of the synchronization circuit; a serial-to-parallel converter connected to an output of the cyclic prefix remover; and a discrete Fournier transform (DFT) stage connected to an output of the serial-to-parallel converter, an output of the DFT stage connected to another input to the synchronization circuit.