Closed-form Expression For Channel Capacity Research Articles

Product of Squared SR Random Variables: Application to Satellite Communication

We investigate the problem associated with the statistics of the product of two squared Shadowed Rician (SR) random variables (RVs). Both SR RVs are independent and nonidentically distributed. The distribution of the product of two squared SR RVs is very important from the satellite communication perspective. We derive approximate expressions of the probability density function (p.d.f.), the moment generating function (m.g.f.), and the cumulative distribution function (c.d.f.) in terms of Meijer-G functions. Furthermore, exact closed-form expressions for higher order moments, channel quality estimation index, and amount of fading are derived. The outage probability is also discussed by utilizing the expression of the c.d.f. An approximate closed-form expression of channel capacity is also derived with the help of the p.d.f. expression. Furthermore, the performance of satellite communication system is discussed in terms of the approximate symbol error rate by using the derived results. Specifically, the derived expression of the p.d.f. is used to develop an approximate closed-form expression of the m.g.f. for an amplify-and-forward-based satellite communication system.

A New Closed-Form Expressions of Channel Capacity with MRC, EGC and SC Over Lognormal Fading Channel

In this work, we derive the closed-form expressions of channel capacity with maximal ratio combining, equal gain combining and selection combining schemes under different transmission policies such as optimal power and rate adaptation, optimal rate adaptation, channel inversion with fixed rate (CIFR) and truncated CIFR. Various approximations to the intractable integrals have been proposed using methods such as Holtzman and Gauss–Hermite approximations and simpler expressions are suggested. Moreover, as an application, the channel capacity of lognormally distributed fading channel in the interference-limited environment is discussed. The obtained closed-form expressions have been validated with the exact numerical results.

A new closed-form of ASEP and channel capacity with MRC and selection combining over Inverse Gaussian shadowing

This paper analyse and investigate the performance of communication system with maximal ratio combining (MRC) and selection combining (SC) over Inverse Gaussian (IG) fading distribution. All formats of coherent and non-coherent modulation schemes are considered and novel analytical expressions of average symbol error probability (ASEP) with diversity are derived. Gamma and IG fading distributions are popularly used as a mathematically less complex solution to lognormal in the open literature. Hence, we provide a comparative analysis between IG and gamma fading with the aim to provide a quantitative measure of the difference between the two distributions in the context of ASEP. Moreover, the novel closed-form expressions of channel capacity under transmission schemes such as optimal rate adaptation (ORA) and channel inversion fixed rate (CIFR) are derived and analysed with MRC and SC diversity over IG fading. The analytical results have been validated with the Monte Carlo simulations and the exact numerical results.

Channel capacity of TAS/MRC system with adaptive transmission and channel estimation errors

This correspondence presents the impact of channel estimation error (CEE) on the channel capacity analysis of multiple-input multiple-output (MIMO) system employing transmit antenna selection and maximal ratio combining (TAS/MRC) under adaptive transmission (ADT) techniques over frequency-flat Rayleigh fading channels. In this paper, we evaluated exact closed-form expressions of channel capacity for TAS/MRC system with CEE under different variable power and variable rate adaptation techniques: (i) optimal power and rate adaptation (opra) (ii) constant power with rate adaptation (cpra) (iii) channel inversion with fixed rate (cifr). The channel state information (CSI) consisting of the signal-to-noise ratio (SNR) level is estimated by the decoder and fed back to the transmitter. Further, the ADT schemes can be operated frame by frame, hence permitting for distinct compromises among the attainable capacity and the corresponding implementation complexity. Numerical outcomes illustrate the impact of CEE on the link capacity and outline the performance characteristics among the distinctive adaptation techniques.

Channel capacity of distributed antenna systems downlink over composite Nakagami fading channel

In this paper, the downlink capacity performance of distributed antenna systems (DAS) with antenna selection are investigated in composite Nakagami channel which take path loss, shadow fading and Nakagami fading into account. According to the performance analysis and using numerical integrations, the probability density function (PDF) and cumulative distribution function (CDF) of the effective output SNR of DAS are derived, respectively. Based on these results, tightly-approximate closed-form expressions of channel capacity and outage probability of DAS in composite Nakagami channel are further derived. These expressions include the ones under composite Rayleigh channel as special cases. Conditioned on the outage probability, a practical iterative algorithm based on Newton's method for finding the outage capacity is proposed. To avoid iterative calculation, another approximate closed-form expression of outage capacity is also derived by utilizing the Gaussian distribution approximation. Simulation results show that the derived expressions have more accuracy than the existing ones, and can match the corresponding simulation well. Thus, the capacity performance of DAS in composite Nakagami channel can be evaluated effectively.

Performance Analysis of the M2M Network over Keyhole Nakagami Fading Channels

The performance of the mobile-to-mobile (M2M) network over keyhole Nakagami fading channels is investigated in this paper. Using the method of the probability density function (PDF) of the signal-to-noise ratio (SNR), the exact and approximate closed-form average symbol error probability (ASEP) expressions are derived for pulse-amplitude modulation (PAM), phase shift keying (PSK),and frequency shift keying modulation (FSK). The exact closed-form expressions for channel capacity are also presented. Then the ASEP and channel capacity performance under different conditions is evaluated through numerical simulations to verify the analysis. The simulation results showed that the performance of the M2M network is improved with the transmitting/receiving antennas and the fading coefficient increased.

Adaptive-Transmission Channel Capacity of Maximal-Ratio Combining with Antenna Selection in Nakagami-m Fading channels

This correspondence presents the channel capacity analysis of maximal-ratio combining with transmit antenna selection (TAS/MRC) in frequency-flat Nakagami-m fading channel with variable power and rate allocation techniques. In this paper, we evaluated exact closed-form expressions of channel capacity for TAS/MRC under different adaptive transmission techniques (1) optimal simultaneous power and rate allocation (opra) (2) optimal rate allocation with constant transmit power (ora) (3) channel inversion with fixed rate (cifr) and (4) truncated version of (cifr). An exact closed-form expression for channel capacity has been derived in uncorrelated Nakagami-m fading channels with single infinite series of tabulated function while the fading index is a real value. Numerical results illustrate the impact of fading severity on the channel capacity and outline the performance characteristics between the distinctive allocation schemes.