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Using a well-known wiretap model, for the first time in this paper, closed-form solutions are achieved for wireless secrecy under dual correlated Rician fading. A novel wireless secrecy and end-to-end (e2e) system analysis employing decode-and-forward (DF) opportunistic relays and an adaptive encoder with on/off transmission are reported. A signal-to-noise ratio (SNR) distribution of dual correlated Rician fading is first obtained as a function of four nested infinite summations, which (i) converges for a finite number of terms, and (ii) is employed to compute secrecy outage probability for a passive wiretapper. Using two-dimensional Laplace transform of the SNR distribution of dual correlated Rician fading, an e2e system analysis is then given by deriving compact expressions for e2e SNR distributions, and e2e ergodic capacity. Relationships between important parameters are elaborated and explained. An asymptotic analysis and proof for infinite summation convergence are also given. It is shown that there is a trade-off between transmission quality and security via line-of-sight power. Simulation results are shown to match theoretical prediction, which validates this work. [ABSTRACT FROM AUTHOR]

Maximal ratio combiner output distributions of multivariate equal-correlated Nakagami- $m$ fading in their single-integral form are derived in this paper. The new distributions provide better alternatives to those obtained under selection combing (SC) diversity. Cross verification is mathematically performed to validate the proposed findings, which exactly reduce to existing results under SC deployment when the diversity order is neutralized. To show the effectiveness of the new findings, ergodic channel capacity is derived. Monte Carlo simulation is shown to match theoretical predictions. The new results diversify theoretical developments under equal-correlated Nakagami- $m$ fading, and initiate new directions for further progress. [ABSTRACT FROM AUTHOR]

Distributions of colluding decode-and-forward (DF) opportunistic relays (ORs) employing maximal ratio combining under outdated channel state information (CSI) and independent and identically distributed (i.i.d.) generalized-Rician fading, including line-of-sight (LoS) fading, are fundamentally reported in this paper for the first time. DF-OR collusion can be initiated by employing a broadcast protocol at the destination. The new findings: 1) generalize existing findings under i.i.d. Rayleigh fading employing selection combining and 2) advance theoretical developments for wireless DF-OR networks. Mathematical expressions for: 1) average bit-error-rate of common modulation schemes and 2) ergodic channel capacity inner bounds are given in the compact infinite-summation form, which can be employed to assess the effectiveness of system coherence, a transmit signal-to-noise ratio, the number of DF ORs, degrees of freedom, and LoS power. Because of the LoS component under generalized-Rician fading, infinite summations must be mathematically employed, which are shown to fast converge for a finite number of terms, effectively realizing their practicality. Monte Carlo simulation results are also given under symbols, which match the proposed theoretical predictions. [ABSTRACT FROM AUTHOR]

Exact secrecy and end-to-end (e2e) system analyses for cooperative wireless networks employing a best-relay-selection method with imperfect or outdated channel state information, an infinite relay buffer size, and a wire-tap channel under dualcorrelatedRayleigh fading are given. The new findings, which are valid for any value of the combined signal-to-noise ratio, generalize existing findings in the literature. Closed-form expressions for probability density function, cumulative distribution function, moment generating function, outage probability under secrecy, and e2e system performance are given using one- and two-dimensional Laplace transform. Secrecy outage probability employing an adaptive encoder is also derived, which coherently links secrecy performance and e2e system performance under dualcorrelatedRayleigh fading for the first time. Effects of amount of fading on secrecy are discussed. Simulation results are shown to match theoretical predictions. Detailed discussions and insight are also given. [ABSTRACT FROM AUTHOR]

Using a well-known wire-tap model, novel wireless secrecy analyses under dual correlated Nakagami- $m$ fading with a real fading parameter $m$ are reported. Infinite summations for incomplete gamma functions are employed to derive compact expressions for secrecy capacity and secrecy outage probability (SOP) under noninteger $m$. Independently, using finite summations, corresponding closed-form findings for integer $m$ are also derived. In the current literature, finite summations for the incomplete gamma functions, whose first arguments and hence $m$ must be an integer, are employed to obtain closed-form expressions for, first, the SOP (with an unknown passive wire-tapper's channel state information), and second, ergodic secrecy capacity (with partially known active wire-tapper's channel state information under slow fading). The new secrecy results for noninteger $m$ generalize the proposed findings for integer $m$ , and existing findings under dual correlated Rayleigh fading for $m=1$. The new findings can thus be comprehensively employed for wireless secrecy computation under dual correlated Nakagami- $m$ fading for real $m$. Infinite-summation convergence and cross verification are also obtained for a finite number of terms, which shows the practicality and consistency of the new findings. For the first time, secrecy analyses employing an adaptive encoder with on/off transmission are performed under dual correlated Nakagami- $m$ fading for real $m$ to not only improve wireless secrecy, but also achieve the eventual successful transmission from a source to a destination. The new SOP results for real $m$ can be employed as lower bounds and complete theoretical secrecy analyses, for SOP under dual correlated Nakagami- $m$ fading with integer $m$. Simulation results are employed to show matching between the proposed findings and existing findings. [ABSTRACT FROM AUTHOR]

Under even degrees of freedom, new single-integral and infinite-summation selection combiner output signal-to-noise ratio and signal-to-interference-and-noise ratio distributions of multivariate equally-correlated generalised-Rayleigh fading for multiuser-multiple-input-multiple-output (MU-MIMO) systems are obtained. The proposed findings can be employed to approximate intractable distributions of multivariate exponentially-correlated Rician fading. An average bit error rate of the differential binary phase-shift keying scheme for MIMO networks is derived using the new distributions, showing their efficiency for network assessment. [ABSTRACT FROM AUTHOR]

Single-integral expressions for cumulative distribution functions of multivariate correlated Rayleigh and Rician fading are studied. Mathematical mistakes in the literature are identified and corrected. Corrections are cross-verified against well-known findings in the literature, which can be employed to advance further theoretical developments for correlated fading. [ABSTRACT FROM AUTHOR]

An estimate of the lower-bound on signal-to-noise ratio (SNR) of the nth-order hyperbolic time–frequency kernel is given. The effects of kernel parameters such as β, τ, n and a on the SNR are discussed. In particular, the direct relationship between the SNR and auto-term slope a is studied in detail. Conditions under which the lower-bound on SNR is obtained are derived. Preliminary observations on a transfer function model with the auto-term slope a and β as inputs, and lower-bound on SNR as output are given. Possible further work is outlined. [Copyright &y& Elsevier]

In this paper, we evaluate two-way relay communication systems in cognitive radio environments. The proposed model includes two subsystems: a primary system and a secondary system. The primary system consists of a primary transmitter and a primary receiver while the secondary includes two terminals exchanging their data via an intermediate relay node. Each network node is equipped with a single antenna and operates under a half-duplex mode. The channel state information (CSI) interference from the secondary node to the primary receiver is assumed imperfect. Using analytical methods, this paper derives the interference probability from the secondary system to the primary receiver and an optimal back-off control power coefficient for the secondary transmitter. To evaluate the secondary system quality, an explicit expression for the system outage probability (OP) and its closed form in the high signal-to-noise region (SNR) is presented. Theoretical results are verified using Monte-Carlo simulation. [ABSTRACT FROM AUTHOR]