This paper describes a design of signal generator based on direct digital synthesis technique (DDS). According to the basic principles of DDS using Matlab/DSP Builder establish DDS model, then compiling by the SignalCompiler tools and generating VHDL code. Finally download the relevant documents to the field programmable gate array (FPGA) chip EP2C5Q208C8N. EP2C5Q208C8N and digital-analog chip ...

In this paper, a precise method for calculating the bit-error rate (BER) of a discrete cosine transform (DCT)-based orthogonal frequency-division multiplexing (OFDM) system on additive white Gaussian noise (AWGN) channels for a Multicarrier-CDMA (MCCDMA) is derived and its BER performance will be compared with the FFT based MC-CDMA. These accurate results are used to examine and compare the BER...

This paper studies the performance of selected chaos-based systems which share their frequency bands with conventional spread-spectrum systems. Such a scenario may occur in normal practice when chaos-based systems are introduced while the conventional systems are still in operation. The particular chaos-based systems under study are the coherent chaosshift-keying (CSK) system and the non-cohere...

Orthogonal Frequency Division Multiplexing is one of the most arising technologies for digital communication. An OFDM signal is the addition of many individual signals modulated over a group of orthogonal subcarriers with same bandwidth. Because of its high robustness against interference, this technology becomes fundamental for modern wireless standards. In the proposed paper, OFDM is implemen...

In this paper, we discuss the performance of the orthogonal frequency division multiplexing (OFDM) wireless communication systems using the binary phase shift keying (BPSK) modulation over Rayleigh fading channel implementing the generalized receiver (GR) constructed in accordance with the generalized approach to signal processing in noise. We compare OFDM-BPSK wireless communication systems ba...

Low-density parity-check (LDPC) coded optical orthogonal frequency division multiplexing (OFDM) is shown to significantly outperform LDPC coded on-off keying (OOK) over the atmospheric turbulence channel in terms of both coding gain and spectral efficiency. In the regime of strong turbulence at a bit-error rate of 10(-5), the coding gain improvement of the LDPC coded single-side band unclipped-...