To solve the issues of the low detection performance and high computational complexity of the available initial ranging algorithms for Orthogonal Frequency Division Multiple Access (OFDMA) systems, a low- complexity initial ranging algorithm with iterative interference cancellation is presented. By using the Parallel Interference Cancellation (PIC) scheme in an iterative fashion, the proposed algorithm detects parallelly the valid paths of active users by means of the strongest power criterion at the receiver, and mitigates the channel estimation interference by employing the parameters estimation of the valid paths. Then it rebuilds and cancels parallelly the detected multiusers signals. Simulation results show that when there are 8 initial ranging users in one ranging time slot and the signal noise ratio is 9 dB, the computational complexity of the proposed algorithm is approximately 25% of that of the Successive MultiUser Detection (SMUD) with interference cancellation algorithm, and the detection performance is improved by 5% compared with SMUD.
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