Cognitive radio is a novel technology that can potentially improve the utilization efficiency of the radio spectrum. Spectrum sensing is the key component of cognitive radio technology. However, detection is compromised when a user experiences shadowing or fading effects. In such cases, user cannot distinguish between an unused band and a deep fade. Thus, cooperative spectrum sensing is propose...

In this paper, we analyze the Bit Error Rate (BER) performance of Golden coded Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system over Rician multipath fading channel. We also compare the performance of the MIMO-OFDM system using Golden code in Rayleigh and Rician multipath fading channels. We discuss the effects of the presence of line-of-sight (LoS) c...

In this paper, the performance analysis of an energy detector is exploited over composite multipath/shadowing fading channels, which is modeled by Rayleigh-lognormal (RL) distribution. Based on an approximate channel model which was recently proposed by the author, the RL envelope probability density function (pdf) is approximated by a finite sum of weighted Rayleigh pdfs. Relying on this inter...

Land mobile satellite communication systems at Ka/K band (30/20 GHz) are attracting more and more attention to researchers because of its frequency band availability and the possibility of using small earth stations and satellite antennas for the systems. However, the Ka/K-band communications also give significant challenges in the system design due to severe channel impairments expected from t...

In this paper, a detailed theoretical analysis of fading margin in an asynchronous code division multiple access (A-CDMA) system is discussed. Rayleigh and Rician frequency-selective slowly fading channels are considered. Probability distribution and density functions of the probability of error are derived for Rayleigh and Rician fading channels. The fluctuations in the channel capacity are pr...

We calculate the capacity of a multiple-antenna wireless link with M -transmit and N -receive antennas in a Rician fading channel. We consider the standard Rician fading channel where the channel coefficients are modeled as independent circular Gaussian random variables with non-zero means (non-zero specular component). The channel coefficients of this model are constant over a block of T symbo...

Radio Frequency Identification (RFID) is currently the hottest technology in wireless communication, in which data transmission with extreme low power or even without power in tag. Software-Defined Radio (SDR) plays an important role for a wireless communications syste m where all the signal processing is implemented in software. In this paper, we first build up a wireless communication simulat...

Introduction: In this paper, we study the design of space–time codes for frequency selective quasi-static fading channels with nonnegligible ISI. It has been shown by Tarokh et al. [1] that the achievable diversity of a space– time code designed for flat fading channel is not reduced if it is used in a frequency selective fading channel. However, a full diversity space-time code designed for fl...

In the present scenario, there is a rising demand of high capacity, high performance and low Bit Error Rate (BER) in Wireless Communication systems. The Orthogonal Frequency Division Multiplexing (OFDM) is an attractive multi carrier modulation technique for wireless transmission systems. In this paper, we discuss the effect of Doppler frequency in Fast Fourier Transform (FFT) based OFDM system...

In this paper we have studied channel models (flat fading and frequency selective fading channels) estimation, adaptive equalization, and demodulation. The technique involves the optimization of the overall impulse response of the transmit and receive filters and effectively reduces the channel to one which is flat fading. This example showed the relative performance of linear and decision feed...