Improving performance of multi-user OFDM systems using bit-wise interleaver

A new bit-wise interleaver is introduced for multi-user orthogonal frequency division multiplexing systems using frequency hopping. In addition to placing adjacent bits (belonging to one complex I/Q symbol) onto different subcarriers, they can be placed at different timeslots or different blocks. Furthermore, the interleaver can be adjusted adaptively based on the corresponding hopping pattern. The performance gain is investigated by simulations