Downlink Multicarrier DS/SFH-CDMA

Abstract

In this chapter, we introduce the slow frequency hopping (SFH) technique to the multicarrier (MC) CDMA systems for downlink overlay situations. Using lower chip rate, which results in a narrower spectrum for each carrier and hopping the signal in frequency, the MC DS/SFH system achieves better performance than the MC DS CDMA system in most cases, especially when the bandwidth of the narrowband interference is narrower than one subchannel. It also exhibits a stable performance against the variations of the narrowband interference location and bandwidth. When there is no narrowband interference, the two systems perform approximately the same. The evaluation is performed over a frequency selective Rayleigh fading channel, with both Gaussian approximation and Monte Carlo simulation.