Simultaneous RTS and Sequential CTS Considering Multiple Cooperative Relays

Abstract

We propose a distributed scheduling algorithm for wireless ad hoc systems that use cooperative transmission in which multiple cooperative relays can transmit at the same time by using an amplify-and-forward (AF) scheme or a decode-and-forward (DF) scheme. Our proposed scheme is a carrier-sense-multiple-access-like (CSMA-like) scheduling algorithm, which uses simultaneous request-to-send (RTS) and sequential clear-to-send (CTS) (SRSC) transmission in which multiple transmitters broadcast RTS at the same time, and the power of CTS transmission changes dynamically according to the relaying scheme used and the number of cooperative relays. Therefore, each cooperative transmission set can recognize efficiently whether its transmission will interfere with neighboring ongoing transmissions. Through performance evaluation by simulation, we show that the proposed scheme can enhance the performance of wireless ad hoc systems that use cooperative transmission.