An automatic method for classifying frequency shift keying (FSK), minimum (MSK), phase (PSK), quadrature amplitude modulation (QAM), and orthogonal division multiplexing (OFDM) is proposed by simultaneously using normality test, spectral analysis, geometrical characteristics of in-phase-quadrature (I-Q) constellation diagram. Since the extracted features are unique each modulation, they can be ...

The paper proposes a novel spread quadrature amplitude modulation (S-QAM) technique with high SNR improvement for high-order QAM channels. Simulated and experimental bit error rate (BER) performance analyses of the proposed technique in blind and non-blind equalizers are obtained by using single carrier (SC) WiMAX (IEEE 802.16-2004) radio. Instead of using any one particular type of channel pro...

A low-complexity feed-forward carrier phase estimation (CPE) technique is presented for dual-polarization (DP)-16-QAM transmission systems. By combining QPSK partitioning, maximum likelihood (ML) detection and phase offset estimation between signals in different polarizations, simulation and experimental results for a 200 Gb/s DP-16-QAM system demonstrate similar linewidth tolerance to the best...

12. Considering discrete-time channels, sketch a chart showing the following plots: (a) Continuous-valued AWGN channel capacity (bits/symbol) as a function of SNR (b) Maximal conveyed information as a function of SNR for the following alphabets: 2-PSK, 4-PSK, 16-QAM, 64-QAM The characteristic shapes of the curves and asymptotic behaviors are essential. 13. The capacity per symbol for a continuo...

We investigate the effects of different phase noise processes of SGDBR laser on coherent systems. The SGDBR device operated well with QPSK modulation at 5 Gbaud, while the performance of 16-QAM was significantly degraded due to excess noise. The white FM noise mainly defines the ultimate performance of coherent reception, but the low frequency excess noise can potentially degrade the performanc...

This review work based on the Performance analysis of OAM-OFDM system in AWGN Channel. In Digital communication system with multi carrier modulation technique can play very important role in all phase of designing and engineering. In this work we discuss about the performance analysis of 16QAM-OFDM system. We compare the performance analysis of different technique used in the 16 QAM OFDM and di...

112106-6868 IJVIPNS-IJENS © December 2011 IJENS I J E N S Abstract—Bit dependency of image compression algorithms introduce error extension effects in transmission of compressed images and considerably reduce the received image quality. Channel coding provides protection against these errors but at the cost of increased bandwidth. Asymmetric modulation methods like QAM and QPSK provide alternat...

The performance analysis of free space optical communication (FSO) systems using relays and spatial diversity at the transmitter end is presented in this paper. The impact of atmospheric turbulence and attenuation caused by different weather conditions and geometric losses has also been taken into account. The effect of turbulence is modeled over a log-normal probability density function. We pr...

Wireless Sensor Network (WSN) holds the potential to open domains to distributed data acquisition. Minimizing the consumption of energy in a wireless sensor network application is crucial for effective realization of the intended application in terms of cost, li fetime and functionality. In this paper, we have tried to find out the average lifetime of the batteries calculated for BPSK, QPSK and...

Approximate Symbol error rate (SER) expressions are derived for receive diversity system employing optimum combining, when both the desired and the interfering signals are subjected to Rician fading, for the case of a) equal power uncorrelated interferers b) unequal power interferers c) interferer correlation. The derived expressions are applicable for an arbitrary number of receive antennas an...