Cognitive jammers are able to deploy advanced strategies that degrade the performance of cognitive radio user communications. In this paper, we study the problem of power allocation in cognitive radio user and jammer games, over parallel Gaussian channels. We model the interaction between a communicator (a transmitter-receiver pair) and a jammer using zero-sum games with continuous action sets;...

This paper presents a software defined radio using Ofdm for high data rate transmission. to demonstrate the concepts of SDR we use a low power fixed-point digital signal processor. for reducing the complexity we use only two operational modes BPSK and QPSK .the adoptability nature using these two modes of OFDM system is discussed. Here we use a straight line method for getting fewer clock signa...

An “RF sensor” network can monitor RSS values on links in the network and perform device-free localization, i.e., locating a person or object moving in the area in which the network is deployed. This paper provides a statistical model for the RSS variance as a function of the person’s position w.r.t. the transmitter (TX) and receiver (RX). We show that the ensemble mean of the RSS variance has ...

In this paper, a cooperative transmission protocol for cognitive radio systems is proposed. In this protocol, the primary system comprises a transmitter (PT), a receiver (PR), and a decode-and-forward relay (Relay), while the secondary system comprises a transmitter (ST) and a receiver (SR). Both the ST and the Relay assist the transmissions of the primary users together. The outage probabiliti...

I. OVERVIEW Target of the work is the evaluation of the potential of impulse radio (IR) communication systems with respect to commercial usage. Therefore a reconfigurable ultra-wideband (UWB) software defined radio (SDR) transmitter has been developed and the concept is presented in this application note. Besides common SDR concepts the developed IR transceiver employs first order bandpass (BP)...

Ultra-wideband is a technology that can be use at very low energy levels for short-range high bandwidth communications by using a large portion of the radio spectrum. In this paper we is specifically focused on the performance of software radio transceiver design for impulse-based UWB with the ability to transmit a raw data rate of 100 Mbps yet encompasses the adaptability of a reconfigurable d...

The problem faced by wireless systems is to find the suitable spectrum bands for the fulfilment of future demands. All of radio spectrum has been allocated different services, user and applications; still it is shown in the observations that the spectrum usage is quite low. Therefore concept of cognitive radio has been used to overcome this problem with the utilisation of spectrum. Cognitive Ra...

This paper describes and analyzes a distributed algorithm for assigning codes in a dynamic, multihop wireless radio network. The algorithm does not require any form of synchronization and is completely distributed. The algorithm can be used for both the transmitter oriented and receiver oriented code assignment. The algorithm is proven to be correct and its complexity is analyzed. The implement...

The paper deals to proposed a cooperative communications to exploit spatial diversity gains inherent in multi-user wireless systems without the need of multiple antennas at each node. Transmit diversity generally requires more than one antenna at the transmitter. However, many wireless devices are limited by size or hardware complexity to one antenna. Which communication channels are in use and...

Secondary receivers in Multiple-Input Multiple-Output (MIMO) Cognitive Radio (CR) networks combat interference from primary transmitters while equipped with whitening filters. However, when the MIMO secondary users are employing Radio Frequency (RF) beam-forming networks at the transmitter/ receiver front ends to improve the MIMO transmission performance, the whitening filters cannot perform in...