Two-tier overlay networks that consist of a conventional macrocell network and femtocell hotspots offer an economical solution for high capacity and extended coverage. However, wireless interference across tiers significantly degrades network performance by restricting spectrum reuse. In this paper, we explore schemes to mitigate cross-tier interference using beamforming in overlay networks. In...

In order to improve the efficiency of spectrum resource usage and the capacity of wireless networks, cooperative relay techniques which utilize the vacant spectrum of primary users for secondary users’ data transmission have been applied in cognitive radio networks. Considering the dynamic time-varying vacant spectrum resources and achievable rate on different channels at relay nodes (RN), the ...

In this paper, we determine the watermark domain that maximizes data hiding capacity. We focus on the situation in which the watermarked signal undergoes lossy compression involving quantization in a specified compression domain. A novel linear model for the process of quantization is proposed which leads to analytical results estimating the data hiding capacity for various watermarking domains...

Objective(s) Comparison of prooxidant-antioxidant balance (PAB) assay with crocin assay. Materials and Methods Twenty eight serum samples were chosen, PAB and the total antioxidant capacity were measured by PAB assay and crocin, respectively, and the correlation of both assays, along with their correlation with other clinical and biochemical parameters, were determined. Results A significa...