Research On Link Scheduling Algorithm In Millimeter Wave Communication

With the significant growth of mobile data traffic in the coming years,60 GHz millimeter-wave(mm-wave)communication shows great potential in high throughput networks to meet this demand.The directional transmission in 60-GHz radio has motivated studies of spatial sharing(SPSH).In IEEE 802.11 ad,a widely acknowledged protocol of60-GHz system,spatial sharing inside a network is supported.In addition,different networks are recommended to transmit in non-overlapping period to mitigate inter-network interference,which is hard to employ in real system under circumstances such as heavy traffic load.However,there is no specific mechanism for spatial sharing with interference mitigation among networks in IEEE 802.11 ad standard.Therefore,the inter-network spatial sharing strategy in IEEE 802.11 ad Wireless Local Area Networks(WLAN)is researched in this thesis.Firstly,based on the IEEE 802.11 ad standard,this thesis establishes the overall system framework and analyzes the existing spatial multiplexing mechanism from key technologies such as channel access,beamforming,and channel measurement.Considering the cumulative effect of interference,SNR is chosen as the decision condition for link coexistence,an effective link scheduling scheme is adopted to further improve the gain of spatial multiplexing.Secondly,two spatial sharing strategies are simulated and analyzed.One is the spatial sharing strategy for interference mitigation between multiple co-channel PBSS based on the IEEE 802.11 ad standard,the other one is the corresponding time scheduling scheme based on mutual avoidance of interference.The simulation results show that the two link scheduling scheme performs well and achieves high spatial multiplexing gain.Finally,based on the existing limited feedback algorithm using adaptive threshold feedback and amplitude quantization,a finite feedback scheduling algorithm based on Givens transform quantization is proposed.Compared with the existing algorithm,the channel coefficient value is quantized by amplitude.The proposed algorithm converts the equivalent channel vector into polar coordinates,feedback rotation angle and vector modulus,thus reducing the number of feedback bits of the beamforming weight value and amplitude.Finally,the scheduling center schedules channel resources based on heuristics,and finds the optimal solution for link scheduling by finding the maximum feasible set for scheduling problems.Applying this approach can significantly reduce data feedback overhead andimprove performance.