Partner selection and subcarrier allocation of time-frequency coded cooperation MC- CDMA in mine tunnel
Zhang Lin-yua · Meitan xuebao · 2014
In terms of the banded structure of underground mine roadways,a cooperative partner selection protocol was proposed for time-frequency coded cooperation MC- CDMA wireless transmission,which is based on the instantaneous signal to noise ratio(SNR) received by base station(BS) and the location of users,and the cooperative partner selected by BS. Due to the channel relativity for neighboring subcarrier,it may cause reduced transmission quality for some spread branches of mine MC- CDMA to allocate subcarrier contiguously,which will affect the performance of wireless transmission. Therefore,a suboptimal subcarrier allocation scheme called subcarrier rotary allocation was proposed,which allocates discrete subcarrier to spread branches with fixed interval. Since the subcarrier's instantaneous channel condition was not taken into account in the suboptimum scheme,it was much simpler than the optimal protocol which allocates subcarrier according to the instantaneous channel condition of subcarrier. Simulation results show that the channel capacity and bit error rate(BER) performance of users are improved significantly with the proposed cooperative partner selection protocol and the subcarrier allocation scheme for the time-frequency coded cooperation MC-CDMA wireless transmission. In this way,the robustness of channel capacity and the reliability of underground wireless communication are enhanced significantly.