Bandwidth- and power-efficient multicarrier multiple access

Orthogonal frequency-division multiple access (OFDMA) gains increasing attention for broadband, high data rate wireless communications. We develop a novel unitary precoded (UP) OFDMA scheme that is particularly appealing for the uplink, because it offers high bandwidth efficiency, and constant modulus transmissions for each user. Theoretical analysis of UP-OFDMA with channel coding shows the performance improvement introduced by unitary precoding. It provides useful guidelines for practical system designs, and also quantifies the performance of UP-OFDMA relative to the single-user bound. Simulations confirm that UP-OFDMA improves performance considerably relative to conventional OFDMA.