A differential successive multiuser ranging detection for OFDMA systems

Ranging is a technology for the uplink synchronization. The objective is to adjust the timing and power of mobile stations (MSs). Due to the channel effect and multiple access interference (MAI), the ranging user detection is challenged. Higher estimation accuracy usually is accompanied with higher complexity or higher resources. In view of this, we propose a feasible and practical method to achieve high performance by the differential ranging detection. At the same time, we combine the multiuser detection to overcome the MAI and the multipath effect. The most important is that the complexity of the proposed method is less than the conventional method when less ranging users transmit signals on the ranging slot.