Ayse Kortun

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In this paper, we study the eigenvalue-based spectrum sensing techniques for multiple-antenna cognitive radio networks. First, we study the extreme eigenvalue distributions of a complex Wishart matrix and then, in contrast to the asymptotic analysis reported in the literature, we derive the exact distribution of the test statistics of (i) maximum eigenvalue(More)
—In this paper, we study the tradeoff between sensing time and achievable throughput of the secondary user that employs robust eigenvalue-based spectrum sensing techniques in the presence of noise uncertainty. First, we study exact distributions of the test statistics for two types of robust eigenvalue-based sensing techniques, namely, the blind generalized(More)
In direct-sequence code-division multiple-access systems, impulsive noise leads to increased bit error rates and hence limits the performance. The main novel contribution of this paper is the improvement achieved on the decorrelating detector by the addition of a nonlinear clipper in order to eliminate impulsive components. The system is studied under(More)
Accurate power control is an essential requirement in the design of cellular dırect sequence code-division multiple-access (DS-CDMA) systems. Effective power control will heavily impact the system capacity. Power control should be able to adjust the power levels of each transmitted signal so that all users will maintain the desired signal-to-noise ratio. In(More)
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