Make random access contentions transparent by orthogonal complementary codes in wireless communications

Transparent contention means that receivers and/or transmitters know the random access contention before data packet transmissions. With transparent contention, channel access can be scheduled to avoid packet collisions. More important, packet priority and QoS can be conveniently managed. This paper proposes new methods which make contention transparent in random access wireless networks. Packet collisions can be completely resolved with the help of orthogonal complementary codes. System throughput approaches the offered load up to near unity. A joint layer design approach is proposed for both the physical layer signal detection algorithm and the MAC layer random access protocol. Theoretical analysis and simulations demonstrate its superior performance.