Hybrid Resource Request Protocol over Multiple Receive Antennas in Wireless Communication Systems

In this paper, we present an efficient random access-based resource request protocol that operates over multiple receive antennas. It is a hybrid form of resource request composed of four-way and two-way handshakes. In many of today´s wireless systems, a resource request basically requires a four-way handshake between a mobile station (MS) and its base station (BS) because the MS can send a resource request message only after the BS allocates resources for the transmission of the message. In the multiple receive antenna environment, however, it is possible to employ a two-way handshake as well by transmitting a preamble piggybacked by a resource request message: When multiple MSs request resources, the BS first obtains the channel information out of the preambles in the received signals and then separates out the multiple resource request messages by applying multi-user receiver. If they are recovered successfully, the resource request process can be completed by a two-way handshake and, otherwise, it can be completed by a four-way handshake as in the existing resource request schemes. Completing resource request by two-way handshake contributes to decreasing the mean delay. The performance of the proposed schemes is analyzed by adopting a Markov chain model. Numerical results confirm the validity of the mathematical modeling and reveal a notable performance gain of the proposed resource request protocol.