Orthogonal Frequency Division Multiplexing (OFDM) is a key technique for achieving high data rates and spectral efficiency requirements for wireless communication systems. This paper presents a modeling and simulation of OFDM based on WLAN standard (IEEE 802.11a). Performance of OFDM is evaluated for different modulation schemes such as PSK, QAM, DQPSK, and OQPSK. The performance of OFDM is com...

This paper considers the bit error probability analysis of Direct-Sequence Code-Division Multiple Access (DS-CDMA) system. A statistical characterization of the decision variable at transmitter and receiver is obtained. System is simulated with OQPSK modulation scheme which when compared with conventional Binary Phase Shift Keying (BPSK) gives improved performance in terms of Probability of Err...

A nyone who's read the past five months' columns should now have at least a general feel for what it takes to get a network node on the air. It was my intention to get everyone familiar with the process, to gain the courage to try it themselves. I urge you to try it. Don't be intimidated by existing networks, or by those who look down upon 1200-baud links-if there's a need for data transport se...

Quadrature Phase Shift Keying (QPSK) and Offset Quadrature Phase Shift Keying (OQPSK) are two wellaccepted modulation techniques used in Code Division Multiple Access (CDMA) system. The Pulse-Shaping Filters play an important role in digital transmission. The type of Pulse-Shaping Filter used, and its behavior would influence the performance of the communication system. This in turn, would have...

Imbalances from imperfect phase modulators can cause distorted signal constellations and interfering tone signals at the carrier frequency in phase-modulated communication systems. The rendered imperfection in the modulated signal inevitably degrades the receiver’s carrier-tracking performance and, for quadraturephase-shift-keyed (QPSK) systems in particular, causes cross-talk between the inpha...

This paper presents a practical architecture for joint source-channel coding of human visual model based video transmission over satellite channel. Perceptual distortion model justnoticeable-distortion (JND) is applied to improve the subjective quality of compressed videos. 3D wavelet decomposition can remove spatial and temporal redundancy and provide scalability of video quality. In order to ...