Patent ID: 7676006

Claim:
A method, comprising: evaluating a Doppler spread associated with a transmission channel with a gain represented by a random process, the evaluating including: transmitting, using a transmitter, on said channel a pilot signal having known fields of symbols; receiving, using a receiver, said pilot signal from said channel; estimating, based on said pilot signal, said channel so as to generate a gain signal indicating said gain; detecting a zero-crossing rate of said gain signal during a given time interval; estimating a signal-to-noise ratio associated with said channel in a manner that eliminates bias due to noise inherent in estimation of said Doppler spread; and estimating a bandwidth of said random process as a function of a reference quantity having: a first term representing an estimate of said zero-crossing rate; and a second term that includes said signal-to-noise ratio of the channel, wherein said bandwidth {circumflex over (f)} D of said random process is estimated according to one of the following relations: f ^ D = ( 3 / 4 ⁢ π 2 ) ⁢ I ^ D ( 2 ) f ^ D = ( 2 / 4 ⁢ π 2 ) ⁢ I ^ D ( 2 ) wherein Î D (2) is said reference quantity and {circumflex over (f)} D is said bandwidth.