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We present a geometric multipath propagation model for a microcell mobile environment. The model provides the statistics for the direction-of-arrival (DOA) of multipath components; also it provides the multipath power delay profiles (PDP), which are used to evaluate the bit error rate (BER) and the signal to interference ratio (SIR) for the direct-sequence(More)
Compressed sensing, viewed as a type of random undersampling, considers the acquisition and reconstruction of sparse or compressible signals at a rate significantly lower than that of Nyquist. Exact reconstruction from incompletely acquired random measurements is, under certain constraints, achievable with high probability. However, randomness may not(More)
In this work we present a comparative study for the transmission of a wavelet-compressed still image using FFT-OFDM over multipath channels with additive white Gaussian noise (AWGN). Rather than using a global threshold for the compression of the wavelet coefficients, we chose to compress the data by transmitting only the low-pass subbands from each(More)
Impulsive noise is one of the major challenges in power line communications and can cause serious problems in OFDM-based PLC systems. In this paper, we propose a combined Time-Domain/Frequency-domain technique for impulsive noise reduction in OFDM-based PLC systems. The performance of the proposed technique is studied against well known time-domain(More)
The clipping and filtering method is analyzed in terms of power savings. The analysis takes account of the gain in the amplifier efficiency due to peak-to-average-power-ratio (PAPR) reduction. Assuming a linear amplifier and a typical digital signal processor, the power savings is shown to be in the order of Watts.
We present a comparative study on Fourier-based OFDM (FFT-OFDM) and wavelet-based OFDM (DWT-OFDM) in DVB-T system (DWT being the discrete wavelet transform).We found that the DWT-OFDM outperforms FFT-OFDM in AWGN and Rayleigh fading channels. For AWGN channel, the gain in term of energy per bit to noise ratio Eb/No was improved by about 5 dB when the system(More)
Sigma-delta modulators are inherently non-linear structures and suffer from many intriguing and unresolved problems. Two approaches are utilized to analyze these structures: analytical and nonlinear approximation techniques. According to the nonlinear approximation analysis, a circle map is proposed to model the dynamics of a third-order sigma-delta(More)
The study investigated the dependance of absorbed mobile phone radiation in terms of specific absorption rate (SAR) values on head size. A dipole and a generic phone model were used to simulate mobile phone at 900/835 MHz, and standard SAM phantom as an adult head model. Three child head models were derived after uniformly scaling down standard head in all(More)
A digital Class-D amplifier based on single-bit processing to be implemented on a field programmable gate array (FPGA) is presented. The main focus of this design is the reduction of noise, a drawback of Class-D amplifiers, by exploring the noise-shaping characteristics of sigma-delta modulation (SDM). The audio signal is retained in the digital single-bit(More)
In this contribution we focus on two principle methods of modelling MIMO radio channel, including the propagation-based and analytical method. In the propagation-based method, we present a space-time geometrical channel model with hyperbolically distributed scatterers for a macrocell mobile environment. On the other hand, popular mathematical models have(More)