A comparison of multiple access techniques in the presence of narrowband interference

This paper presents a comparison of several multiple access techniques in the presence of narrow-band interference. The analysis covers time-division multiple access (TDMA), code-division multiple access (CDMA), and orthogonal frequency-division multiple access (OFDMA). The results indicate that contrary to a common belief, CDMA with pseudo-noise spreading sequences is more sensitive to narrowband interference than is TDMA. Another finding is that orthogonal CDMA behaves similarly to OFDMA in the sense that the degradation is not the same for all users. Finally, the results confirm the superiority of OFDMA to all other multiple access techniques in this environment.