UPLINK INTER-CARRIER INTERFERENCE CANCELLATION FOR OFDMA SYSTEMS

摘要

Inter-carrier interference (ICI) cancellation in an OFDMA receiving signals from two transmitters is performed by identifying the transmitted sub-carriers that cause the largest ICI to sub-carriers received from other transmitters, and removing the ICI contribution from these sub- carriers. This may be accomplished by calculating the ICI terms only based on the interfering sub-carrier and the frequency offset. Alternatively, the transmissions causing the ICI are demodulated, the ICI on other signals is then determined and subtracted, and other signals are then demodulated. Which transmissions cause the largest ICI on others depends on the relative strength of the corresponding sub-carriers and how much orthogonality is lost. The latter might be due to frequency error, Doppler spread, or a combination of both.