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—We propose a new spectrum-sensing technique based on the sample autocorrelation of the received signal. We assume that the received signal is oversampled and allow for frequency offset between the local oscillator and the carrier of the primary signal. We evaluate the performance of this algorithm for both additive white Gaussian noise (AWGN) and(More)
—Traditional design rules for cellular networks are not directly applicable to code division multiple access (CDMA) networks where intercell interference is not mitigated by cell placement and careful frequency planning. For transmission quality requirements , a minimum signal-to-interference ratio (SIR) must be achieved. The base-station location, its(More)
The optimal subcarrier, bit and power allocation problem for multiuser OFDM systems has been investigated. To achieve a numerically efficient solution the problem is divided into two separate optimization problems: one for subcarrier allocation and one for bit and power allocation. A novel and computationally efficient algorithm is presented for the bit and(More)
A new MAC protocol which supports peer-to-peer direct communication is introduced for a packet switched wireless network. Terminals that are located within range of each other and are sufficiently isolated from the base station can communicate with their peers directly without the use of the base station as a relay. Slotted Aloha is used as the access(More)
Wireless sensor networks are prone to node misbehavior arising from tampering by an adversary (Byzantine attack), or due to other factors such as node failure resulting from hardware or software degradation. In this paper, we consider the problem of decentralized detection in wireless sensor networks in the presence of one or more classes of misbehaving(More)
The problem of binary hypothesis testing is considered in a bandwidth-constrained densely populated low-power wireless sensor network operating over insecure links. Observations of the sensors are quantized and encrypted before transmission. The encryption method maps the output of the quantizer to one of the possible quantizer output levels randomly(More)
—We consider the problem of spectrum sensing in cognitive radios when the receiver of the secondary user (SU) is equipped with a multi-antenna system. Using an estimate of the cross-correlation among the signals received at different antenna elements, we propose a blind detection method which assumes no prior knowledge of the signaling scheme used by the(More)
—This paper presents a novel approach for designing a call-admission control (CAC) algorithm for code-division multiple access (CDMA) networks with arbitrary call-arrival rates. The design of the CAC algorithm uses global information; it incorporates the call-arrival rates and the user mobilities across the network and guarantees the users' quality of(More)