We propose an adaptive fractional window increasing algorithm (AFW) to improve the performance of the fractional window increment (FeW) in (Nahm et al., 2005). AFW fully utilizes the bandwidth when the network is idle, and limits the op-erating window when the network is congested. We evaluate AFW and compare the total throughput of AFW with that of FeW in different scenarios over chain, grid, random topologies and with hybrid traffics. Extensive simulation through ns2 shows that AFW obtains 5% higher throughput than FeW, whose throughput is significantly higher than that of TCP-Newreno, with limited modi-fications.
Liang-hui DING Wen-jun ZHANG Xin-bing WANG Liang QIAN You-yun XU
In this paper,a distributed compressive spectrum sensing scheme in wideband cognitive radio networks is investigated.An analog-to-information converters(AIC) RF front-end sampling structure is proposed which use parallel low rate analog to digital conversions(ADCs) and fewer storage units for wideband spectrum signal sampling.The proposed scheme uses multiple low rate congitive radios(CRs) collecting compressed samples through AICs distritbutedly and recover the signal spectrum jointly.A general joint sparsity model is defined in this scenario,along with a universal recovery algorithm based on simultaneous orthogonal matching pursuit(S-OMP).Numerical simulations show this algorithm outperforms current existing algorithms under this model and works competently under other existing models.
