Estimating link quality using a pilot interpolation scheme based on carrier and time fading correlations

摘要

This invention applies to pilot-assisted multi-carrier communications systems. Pilots are transmitted in some but not all of the carrier-time bins. Estimates of a channel quality metric such as a mean square error (MSE) are produced for carrier-time bins which do not have a pilot by applying an interpolative filter (equation 27) to measurements performed on pilot signals in other bins. The interpolative filter exploits carrier fading correlations and time fading correlations. Preferably, filter coefficients are based on measurements of time fading correlations and carrier fading correlations. Such measurements may be carried out at an earlier time. The fading time correlation may be modeled by an exponential decay function with a time "constant" u which is dependent on the velocity of a receiver (equation 1000). In one embodiment a value for this parameter is determined for a receiver at a first speed and the value of the parameter for a receiver at a second speed is predicted by scaling the value of the parameter at the first speed by the ratio of speeds (equation 6000).