Patent ID: 8498346
Filing Date: 2013-07-30
Classification: H04L

Abstract:
1. A method of decoding signals simultaneously received from a plurality of mobile stations at a base station having a plurality of receive antennas, each associated with a receive-signal path, the method comprising: transmitting signals to the mobile stations by the base station, the signals comprising a plurality of orthogonal frequency subcarriers in accordance with an orthogonal frequency division multiple access (OFDMA) technique; for each receive-signal path, separately demodulating training signals received from each of the mobile stations; generating channel estimates for each of a plurality of spatial channels between the mobile stations and the base station based on the separately demodulated training signals; generating a carrier-frequency offset (CFO) for each of the mobile stations by performing an iterative decoding process that includes removal of portions of the received training signals transmitted by mobile stations other than a current mobile station to generate the CFO for the current mobile station; concurrently receiving non-orthogonal data signals from the mobile stations over the spatial channels; and applying the channel estimates and the multiple CFOs to the data signals on a station-by-station basis to generate a separate data stream associated with each mobile station, wherein the data signals comprise voice-over-IP (VoIP) corresponding to the separate data streams associated with each mobile station.