Patent ID: 7639731

Claim:
A system for carrier frequency estimation for a spread-spectrum signal receiver via symbol rate estimation in presence of carrier frequency error caused by Doppler shift comprising: a signal acquisition block for acquiring a transmitted spread-spectrum signal, said signal acquisition block having a signal acquisition function to detect presence of the spread-spectrum signal, said signal acquisition block determining an estimate of a symbol rate error caused by Doppler shift; a carrier frequency error estimation block for determining an initial carrier frequency error, said carrier frequency error estimation block accepting as input the symbol rate error estimate from said signal acquisition block, wherein the system for carrier frequency estimation uses the symbol rate error to determine carrier frequency error, the transmitted spread-spectrum signal having a known nominal carrier frequency and a known nominal symbol rate, and wherein said carrier frequency error estimation block multiplying said symbol rate error estimate by a ratio between the nominal carrier frequency of the transmitted spread-spectrum signal and the nominal symbol rate of the transmitted spread-spectrum signal to determine the initial carrier frequency error, and outputting the initial carrier frequency error as an initial carrier frequency error signal.