Near-far problem in noise-based frequency-offset modulation

A multiple-access noise-based frequency offset modulation (N-FOM) system is studied in the context of near-far problem. A closed-form expression for the signal-to-noise ratio is derived and the bit error rate (BER) is evaluated. The result shows that the near-far problem compromises the performance of the multiple-access N-FOM system. Performance comparison with a standard spread-spectrum system indicates that the near-far problem has an inherently different effect on the N-FOM communication. The error rate of a node in the N-FOM system increases at a much higher rate as the number of simultaneous communication links increases. However for small number of simultaneous links, an adaptive power control scheme can help minimize the threat of the near-far problem.