Patent ID: 7643588
Filing Date: 2010-01-05
Classification: H04L

Abstract:
1. A method for estimating fading coefficients, in a receiver of a wireless communications system, of at least two transmission channels of at least a sequence of symbols to be transmitted in time intervals of duration equal to a symbol interval, the method comprising: at a transmitter of the wireless communications system, for each symbol of the at least one sequence, generating a respective Amplitude Modulated-Phase Shift Keyed (AM-PSK) signal to be transmitted by multiplying the value of a symbol by a PSK modulated signal with a phase corresponding to the symbol to be transmitted; at the transmitter, transmitting a first AM-PSK signal corresponding to a first symbol on a first channel, and transmitting at least a second AM-PSK signal corresponding to a second symbol on a second channel; at the receiver, receiving a combination signal which is a combination of the first and second AM-PSK signals; in an extraction path of the receiver, extracting a first DC component from the received combination signal by coherent demodulation locked to a first estimated phase of the first symbol; in another extraction path of the receiver, extracting a second DC component from the received combination signal by coherent demodulation locked to a second estimated phase of the second symbol; in a digital unit of the receiver, estimating fading coefficients of the two transmission channels based upon the first and second DC components, estimations of the first and second symbols and mutual outphasing between the corresponding first and second AM-PSK transmitted signals, and generating the estimated first and second phases corresponding to the estimations of the first and second symbols.