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Fading is a significant part of any wireless communication system. Rayleigh, Rice and Nakagami-m are traditional fading channels but in some specific cases these fading distributions do not properly fit the experimental measured data, which demands the use of more general fading distributions. The Kappa-Mu distribution is general distribution that includes the Rice, the Nakagami-m, the Rayleigh, and...
This paper presents the simulation and performance analysis of WiMAX (Worldwide Interoperability for Microwave Access) system along with efficient wireless channels using real time image and speech transmission. WiMAX is the commercialization of the IEEE 802.16 standard, an evolving standard initiated at the National Institute of Standards and Technologies in 1998 before being transferred to the IEEE...
In this paper, the BER performance of OFDM-BPSK 16--QAM and 64--QAM system over various multhipath fading channel has been reported. Orthogonal Frequency Division Multiplexing (OFDM) is a key technique for achieving high data rates and spectral efficiency requirements for wireless communication systems. However in fading environments the bit error rate (BER) increases. The performance can be improved...
We investigate the outage probability and the average bit error rate (BER) of a dual-hop fixed gain relaying system in the presence of co-channel interference and thermal noise at the relay and the destination. Our analysis assumes Rayleigh fading for the source-relay and relay-destination channels and Rician fading for the interfering channels. We present new closed-form/series expressions for the...
The work is related to the use of error correction coding and adaptive equalization as an aid to Maximal Ratio Combining (MRC) in order to improve bit error rate(BER)s of received signals in wireless channels with fading characteristics. Several modulation schemes are used in the transmission in Gaussian, multipath Rayleigh and Rician fading channels. The work adopts a few error correction codes and...
In many wireless communication systems, the phase of the received signal can not be tracked accurately due to the random time-varying nature of the channel. Apart from the degradations caused by multipath fading and additive white Gaussian noise (AWGN), the imperfect phase estimation results in additional bit errors at receiver. In this paper, a simple semi-analytical method is presented for evaluating...
Spectrum sensing is the key component of cognitive radio technology. However, detection is compromised when a user experiences shadowing or fading effects. Thus, cooperative spectrum sensing is proposed to optimize the sensing performance. We focus on cooperative spectrum sensing in Rayleigh, Ricean and Nakagami fading channels. Centralized detection approaches, different data fusion rules and closed...
The effectiveness of different diversity combining techniques in improving the bit error rate (BER) performance of a direct-sequence code-division multiple-access (DS-CDMA) system is presented in this paper. The overall performance of a DS-CDMA system is degraded by multipath fading and additive white Gaussian noise (AWGN). To evaluate the degradation, the expression for the conditional BER, conditioned...
The effects of multipath fading and additive white Gaussian noise (AWGN) on the bit error rate (BER) performance of direct-sequence code-division multiple-access (DS-CDMA) systems is studied in this paper. The expression for the conditional BER, conditioned on a given level of fading is derived and then the unconditional BER is evaluated. The BER performance results of the system are evaluated in...
Sensing of orthogonal frequency division multiplexing (OFDM) signals at low signal-to-noise ratio (SNR) is of great importance for cognitive radio (CR) communications due to the wide applications of OFDM in many existing and evolving broadband wireless communications. In-band pilots, multiplexed with the data-carrying subcarriers, provides one distinct feature of OFDM signals. The objective of this...
In this paper, the average bit error rate (BER) performance of square M-level quadrature-amplitude modulation (M-QAM) with imperfect channel estimation via LMMSE under Gaussian-error model is addressed with maximal-ratio combining (MRC) and equal-gain combining (EGC) schemes. The channels are modelled as frequency-flat Ricean fading corrupted by additive white Gaussian noise (AWGN). Average output...
We present bit error rate (BER) expressions of pi/4 shifted differential quadrature phase shift keying (pi/4-DQPSK) with single and multi-channel reception over generalized fading channels in presence of additive white Gaussian noise (AWGN). Slow flat small scale statistical fading models, namely Rayleigh, Rician, Nakagami-m and Hoyt fading has been assumed. Moreover, to improve the link quality receiver...
Analytical solutions for the average symbol error rate of coherent M-ary frequency shift keying (MFSK) modulation schemes operating over frequency non-selective slow fading channels corrupted by additive white Gaussian noise (AWGN) are derived. Starting from the alternate expressions for integer powers (n < 5) of Gaussian Q function, the symbol error probabilities (SEP) are obtained using probability...
The modeling of wireless channels vary greatly in different propagation environments. For example, the line-of-sight (LoS) radio links and non-line-of-sight (NLoS) are two basic channel models in wireless communications, but they are totally different from each other. For a LoS channel, if the signals propagate in an additive white Gaussian noise (AWGN) environment, it is referred to as an AWGN channel...
In this paper, we present an analytical model aimed to evaluate effects of very slow Nakagami/Ricean fading, shadowing and additive Gaussian noise on the mutual interdependence between successive errors in NCMFSK, MCPSK and MCQAM systems. We present the closed form solutions for transition probabilities and show that strong amplitude correlation within several successive signaling intervals, due to...
The low-SNR capacity of M-ary PSK transmission over both the additive white Gaussian noise (AWGN) and fading channels is analyzed when hard-decision detection is employed at the receiver. Closed-form expressions for the first and second derivatives of the capacity at zero SNR are obtained. The spectral-efficiency/bit-energy tradeoff in the low-SNR regime is analyzed by finding the wideband slope and...
The ergodic capacity of single input multiple output (SIMO) wireless communication systems over Nakagami-m fading channels is available in the literature for the case of identically independent distributed (i.i.d.) subchannels. However, the non- identically independent Nakagami-m case is more practical and has not been considered in the literature. In this paper, we derive an analytical expression...
Due to the increasing interest in mobile/wireless communication, there has been a continuous research in antenna diversity to combat fading. And the model of correlated and unbalanced diversity branches reflects the real-world scenario. The diagonalizer is introduced here before the diversity branches are combined, which can transform the correlated and balanced branches to the uncorrelated and unbalanced...
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