Patent ID: 7397758
Filing Date: 2008-07-08
Classification: H04L

Abstract:
1. In an OFDM receiver to wirelessly receive a packet of information that includes a known transmitted part, the receiver including a signal-to-tone transformer to determine the modulated subcarriers of a received signal corresponding to the received packet, an apparatus comprising: a channel storage unit coupled to the signal-to-tone transformer including: a channel corrector coupled to the channel storage unit and to the signal-to-tone transformer to channel correct the modulated subcarriers of the received signal, the correcting using the latest updates from the contents of the memory subsystem; the channel corrector to form channel corrected constellation values for the received signal; a decision and channel drift circuit coupled to the channel corrector to make decisions to form post-decision values corresponding to the channel corrected constellation values and to form a measure of the channel drift using the formed post decision constellation values and the constellation values prior to the post-decision values being formed; and a weighting and summing circuit coupled to the channel storage unit to update the memory subsystem with a weighted sum of the pre-update function in the memory subsystem and a quantity determined from the pre-update function and the measure of the channel drift between symbols, such that the memory subsystem contents track channel drift from symbol to symbol, the tracking according to the relative weightings of the weighted sum.