Comparison of orthogonal CDMA and slow frequency hopping (SFH)/TDMA for picocell communications on the basis of spectral efficiency and robustness

In this analysis, the effects of co-channel interference, unintentional interference and fading on an orthogonal (O)CDMA and a slow frequency hopping (SFH)/TDMA are investigated. Both OCDMA and SFH/TDMA are small cell, low mobility systems without low-rate speech coding and other complex baseband signal processing. Further, time division duplexing (TDD) rather than frequency division duplexing (FDD) is used. Both systems have the same number of channels, system bandwidth, cell layout and voice activity detection. Following the investigations, we have found that OCDMA and SFH/TDMA are very much the same on the basis of capacity. However, SFH/TDMA is more robust to unintentional interference than OCDMA in an unlicensed environment because of easier channel switching and stronger signal-to-noise ratio under stronger jammers.