Smart random channel access in OFDM systems by joint signal processing and packet scheduling

Wireless LAN and many other wireless communication systems have applied OFDM (Orthogonal frequency division modulation) to mitigate multipath. Considering that the requirement of random access may reduce performance due to contentions, in this paper we show that OFDM techniques can assist random access contention resolution. A method is proposed with both OFDM-based physical layer signal processing and MAC layer packet scheduling. It is based on the separation of collided packets in OFDM, which is assisted by the scheduling protocols in the MAC layer. It provides a new way to improve the performance of random access in OFDM-based systems such as wireless LAN. Contentions can be completely resolved, which improves throughput. QoS may also be supported in random access networks.