Abstract：A new technique of joint estimation of Carrier Frequency Offsets (CFOs) is proposed based on maximum-likelihood estimation using two distributed receive antennas helping for each other for flat-fading Rayleigh channels. By utilizing the prior information of the carrier frequency, the oscillators’ accuracy of transceiver antennas and the maximum speed of mobile station, the range of the difference of two CFOs is determined. Taking advantage of this result, when joint searching correlation outputs from two distributed receive antennas, the frequency searching range can be reduced compared with existing methods. Simulation results show that when the Signal-to-Noise Ratio (SNR) is 5 dB, the Mean-Square Error (MSE) performance of joint CFOs estimation outweighs existing algorithms by more than one order of magnitude on condition that the carrier frequency is 2 GHz, the oscillator’s accuracy of transmit antenna is 10 ppm, the oscillators’ accuracy of distributed receive antennas is 1 ppm and the maximum mobile speed is 120 km/h.
2011, Vol. 33 
