| 摘要 |
Processing a signal received over a wireless channel involving an apparatus 104 comprising: a channel searcher 110 configured to determine a profile of the channel in the form of energy values for a plurality of rays at respective channel positions, and an equaliser 106, 114 for equalising the signal based on a variable window length of the equaliser. The channel searcher is configured to estimate dispersion of the channel by determining 120 a measure of variance of ray distance from a reference position within the channel profile weighted by ray energy. The equaliser is coupled to the channel searcher and arranged, under control of a controller 116, to vary the window length in dependence on the measure of energy-weighted ray distance variance. The reference position may be the mid-point energy centroid of the channel profile. The equalizer may adapt the window based on an approximated model that the energy of the channel follows a probability distribution, such as a Gaussian distribution. The adaption may be dynamic so as to adapt repeatedly for changing channel conditions or varying multi-path interference. Outlying rays may be discarded from the profile before measuring the energy-weighted ray-distance variance or energy centroid. The channel profile may be determined 118 based on a convolution of the received signal with a pilot signal. |
