'Institute of Electrical and Electronics Engineers (IEEE)'
Doi
Abstract
In this paper the performance of Carrier Interferometry (CI) and Pseudo-Orthogonal Carrier Interferometry (PO-CI) [1] implementations of Multi-Carrier Code Division Multiple Access (MC-CDMA) are investigated. Comparisons are made with the performance of traditional MCCDMA (incorporating Hadamard-Walsh spreading codes) [2],[3] and Coded Orthogonal Frequency Division Multiplexing (COFDM) [4]. These systems are simulated over a 20MHz bandwidth, wideband, wide-sense stationary, statistically uncorrelated Rayleigh fading channel suffering additive white Gaussian noise (AWGN) and phase noise. The two channel models employed are consistent with the Model B ‘Indoor and Office’ and Model B ‘Outdoor to Indoor and Pedestrian’ test environment specifications proposed by ETSI for UMTS Terrestrial Radio Access (UTRA) [5]. The BPSK CI system was found to outperform both of the equivalent COFDM and MC-CDMA systems, providing 1dB and 1.5dB performance gains respectively at a bit error rate (BER) of 10-3. The BPSK PO-CI system, shown to offer twice the capacity of the equivalent MC-CDMA, COFDM and CI systems, was found to offer the same performance as MC-CDMA. For higher order modulation schemes, the CI system’s performance was found to equal that of the equivalent MCCDMA system, whilst the performance of PO-CI was found to be very poor. In the presence of phase noise, the CI system was found to outperform the MC-CDMA and COFDM systems, suffering a far lower performance loss for a given level of phase noise and providing a softer fail as this level was increased. This soft fail characteristic was also observed in the PO-CI system
