Based on novel inverse-type PDF formulae for large-scale shadowing/fluctuations, we derive novel unified probability density functions (PDFs) and moment generating function (MGF) formulae that characterize wide ranging of generalized composite fading distributions in radio frequency and free-space optical wireless communications channels. By specifying four fading parameters according to specific composite fading models, the unified PDF and MGF formulae enable us to unify and characterize wide ranging of existing and numerous novel generalized composite fading distributions. These unified PDF and MGF formulae are applicable for deriving generalized performance metrics that can in turn be further specified and evaluated according to various known and numerous generalized composite fading channel models.

We derive novel unified probability density function (PDF) formulae of the instantaneous envelope, power and signal-to-noise ratio (SNR), for a generalized composite fading process that models the multiplicative effect of small-scale fading and large-scale shadowing/fluctuations in radio frequency and free-space optical wireless communications channels. By specifying four fading parameters according to specific composite fading models, the unified PDF formulae enable us to unify and characterize wide ranging of existing and numerous novel generalized composite fading distributions. We also present unified analysis and derive general closed form formulae for channel capacity in terms of four parameters of the unified PDF. Such generalized performance metrics can then be further specified and evaluated according to various known and numerous novel composite fading channel models.

Novel closed form formulae of iterative optimal power control and allocation, and criterion for optimal subcarrier allocation are derived for downlink of multicarrier non-orthogonal multiple access (MC-NOMA) systems. For the first time, we present closed form water-filling formulae that quantify exactly the following effects of multiple access interference for optimal power allocation of MC-NOMA downlink: (i) Each user should take into account the sum of interference from other stronger users plus the receiver Gaussian noise as an equivalent interference in each subcarrier; (ii) The sum of each user’s interference to other weaker users should be accounted as factors which determine the distinct water levels in each subcarrier of each of the other weaker users. We also propose novel iterative water-filling algorithm and projected conjugate gradient algorithm that facilitate iterative computation of optimal power allocation for MC-NOMA downlink.

Novel closed form formulae of iterative optimal power control and allocation, and a criterion for optimal subcarrier allocation, are derived for uplink of multicarrier non-orthogonal multiple access (MC-NOMA) systems. Our new formulae provide intuitive insights on how to optimally allocate subcarriers and power to MC-NOMA (and as a special case, MC-OMA) users. In particular, the novel water-filling power allocation formulae provide a mean to iteratively compute optimal power allocation for a general NOMA cluster size. Convergence of the iterative algorithm and sum rate performance of MC-NOMA system are presented and compared with MC-OMA system.

In this paper, we propose a novel optimization strategy for energy-efficient day-ahead energy management and economic power reserve capacity allocation for frequency regulation, by jointly utilizing battery energy storage systems (BESSs) and demand-responsive (DR) fans at the distribution level. Specifically, we consider a smart building with renewable energy integration. The building owns a BESS and is willing to take part in frequency regulation service by allocating a proportion of its BESS capacity as power reserve capacity and receiving monetary reservation fee in return. Due to the high cost of BESS, its limited capacity, and significant degradation caused by excessive charging and discharging, we consider DR fans as a viable low-cost capability of the smart building for energy cost saving and frequency regulation. Particularly, we consider modern fans of the heating, ventilation, and air conditioning (HVAC) systems that can vary their speeds (and thus energy consumption), subject to satisfying user comfort constraints. Simulations results based on the real renewable energy and load data show that our proposed joint optimization strategy is effective in reducing the total energy cost of the building and at the same time providing a higher power reserve capacity to the grid.

This paper studies the energy management problem for two self-interested microgrids with integrated renewable energy and energy storage systems, which can exchange energy with each other through the transmission line connecting them. Microgrids are willing to cooperate if and only if both can benefit from the energy cooperation, e.g. achieve lower energy costs as compared to the without energy cooperation case, while sharing limited information due to privacy considerations. We thus propose an iterative algorithm for the partially cooperative energy management problem, which aims to reduce energy costs of both microgrids simultaneously, while sharing limited information. To provide performance benchmark, we also consider the fully cooperative energy management problem, for which we ideally assume that microgrids share all their information to minimize their total energy cost. Last, we evaluate our proposed algorithms for the partially and fully cooperative energy management via simulations based on the Tucson power system data.

In this work, we focus on a cognitive radio (CR) femtocell network that operates in an orthogonal frequency-division multiple access (OFDMA)-based primary user (PU) network. Due to the lack of centralized planning, the home eNode B (HeNB) or base stations of femtocells are installed in an ad-hoc manner by increasing number of home subscribers. Therefore, femtocell network requires proper interference management, preferably in a distributed way, to achieve maximum total spectral efficiency. In this work, we present optimal solutions for subcarrier and power allocation in OFDMA-based femtocell radio uplink. The new results provide us a simple and yet intuitive interpretation on how to optimally allocate the subcarriers to different cognitive radio users. We also explain how the newly derived solutions can be implemented distributively, and present a distributed joint subcarrier and power allocation scheme for the uplink of OFDMA-based cognitive femtocell users. Simulation results are presented to highlight the convergence of the proposed scheme to achieve maximum throughput performance.

TV White Space (TVWS) promises to deliver better spectrum utilization by allowing secondary TVWS devices to access the channels allocated to primary users when these channels are unused. However, the current spectrum access control via geo-location database (GLDB) approach does not provide quality of service (QoS) differentiation for TVWS devices which is one of the greatest concerns for devices utilizing shared spectrums. In this paper, we proposed a new scheme called GLDB-Q where this new scheme is able to provide certain level of QoS differentiations for TVWS devices and service classes. We present three criteria for high priority access and four mechanisms for spectrum allocations. Analysis and numerical results are presented to show that the proposed schemes are useful to guarantee the QoS requirements of TVWS devices when the system load is high. This new GLDB-Q scheme allows better regulatory control over the spectrum allocation so as to better utilize the shared spectrum while allowing QoS differentiation. This new capability is important as it will allow even better acceptance of TVWS for more critical services.

We study power and rate adaptation for cognitive radios in fading channels, with the objective to maximize the average spectral efficiency of the secondary user (SU) transmitter. The average transmit power and bit error rate (BER) constraints of the SU is considered, together with either the short-term or the long-term outage constraint over the channel state of the primary user (PU). In each case, the optimal power and rate solutions are derived. Unlike previous works on power and rate adaptation for cognitive radios, in this work the cochannel interferences between the SU and PU are explicitly modeled and related to their respective average BER and outage requirements, as well as their respective power and rate variables. Numerical results are presented to provide insights into the dynamics of the power and rate solutions.

Evolutionary algorithms like genetic algorithms and ACO are potential candidates for solving any NP-hard problem, because of their ability to obtain acceptable suboptimum (or sometimes could be the optimum) solutions. This paper proposes an Ant Colony Optimization (ACO) based algorithm to solve the centralized resource allocation problem of a multicell multiuser OFDMA network. The proposed ACO is assisted by a water filling algorithm for power allocation. Two metrics used in ACO algorithms: the visibility and the trail intensity are defined so that they are suitable to evaluate the solution. Visibility is used to select subcarriers and power which increase the total transmitted bit of the cell while trail intensity gives solutions which decrease the inter-cell interference. Simulation results show that with these definitions, the proposed algorithm is working successfully and increases the total network transmitted bits without increasing the maximum transmit power level.

Two adaptive joint power and bandwidth control schemes are proposed for multiple secondary user (SU) transmitters to optimize the spectral efficiency in cognitive radio transmission through spectrum sharing. By exploiting agile bandwidth transmission strategy for cognitive radio users, we present a unified solution to two problems of joint power/rate control and joint power/bandwidth control in dynamic spectrum allocation. Our main objective is to maximize the average spectral efficiency of the commonly in-used portion of the frequency band, subject to the tolerable interference limit at the primary user (PU) that is present. The proposed schemes are applicable to many scenarios, for examples, where two or more SUs are accessing the same frequency band with equal right, or where two or more SUs are accessing the frequency spectrum used by a PU who has a higher priority. Simulations results are presented to show that the proposed suboptimal algorithm also achieves near optimal spectral efficiency.

We study and propose joint power control and cell-site selection schemes for cognitive cellular radios in fading channels. New analytical result on the cognitive radio cell coverage is presented in terms of the outage probability requirement of the primary cellular radio user. A new interference model for the secondary user (SU) is proposed, which includes the transmit powers from all the primary radio (PR) system co-channel base stations, as well as the transmit powers from multiple secondary transmitters. Joint power control and cell-site selection schemes are presented to maximize the total throughput of the SUs, and to guarantee the quality-of-service (QoS) of the primary cellular radio user in terms of outage probability.

We study and propose power control schemes for cognitive radios in Nakagami fading channels. A general model is adopted, which includes the effects of transmit power control from the primary user (PU) transmitter, as well as the transmit power control from multiple secondary user (SU) transmitters, to the PU and each SU. We found that for high signal-to-interference-ratio (SIR) case in Nakagami and Rayleigh fading channels, the outage probability constraint can be upper bounded by an equivalent interference constraint, and the problem for maximizing the total SU spectrum utility can be written as a convex optimization problem which can be solved efficiently. An iterative power control scheme is also presented to maximize the total spectrum utility of the SUs, and to guarantee the quality of service (QoS) of the PU in terms of outage probability.

We study the optimal power and rate adaptation for cognitive radio (CR) transmission, which maximizes the average spectral efficiency of the secondary user transmitter (ST) subject to average BER constraint for secondary user receiver (SR) and average BER or interference constraint at primary user receivers (PR). Adaptive power and rate adaptation is adopted by the ST to guarantee the performances of both PR and SR, while constant power and fixed modulation is used by the PT. It is shown that in addition to the channel gains of the secondary user (SU), the ST also needs to know the primary user (PU) channel gains, the BER and SINR at the PR. Numerical results on the spectral efficiency of the SU are presented as function of various PU and SU channel gains.

We study joint power control and adaptive modulation for cognitive radios in an interference channel with multiple primary users (PUs) and multiple secondary users (SUs). By exploiting the PU channel (in terms of signal-to-interference-plus-noise-ratio (SINR)) and the PU interference to SUs, two iterative power control algorithms are proposed to optimize the total throughput performance of CR systems, subject to the tolerable interference limits at the PUs. In the proposed Algorithm 1, we show that for optimal throughput performance, in addition to the channel gains from the SU transmitters to the PU and SU receivers (as commonly assumed in the literature), the SU transmitters also need to know the PU interference to the SU receivers, as well as the SINRs at the PU receivers. In the proposed Algorithm 2, the SU transmitters need to know only the PU interference to the SU receivers, in addition to the channel gains from the SU transmitters to the PU and SU receivers, but not require to know the PU channels.

This paper studies the wirelesstwo-wayrelaychannel(TWRC), where two source nodes, S1 and S2, exchange information through an assisting relay node, R. It is assumed that R receives the sum signal from S1 and S2 in one time-slot, and then amplifies and forwards the received signal to both S1 and S2 in the next time-slot. By applying the principle ofanaloguenetworkcoding(ANC), each of S1 and S2 cancels the so-called "self-interference" in the received signal from R and then decodes the desired message. Assuming that S1 and S2 are each equipped with a single antenna and R with multi-antennas, this paper analyzes thecapacityregionof an ANC-based TWRC with linear processing (beamforming) at R. The capacity region contains all the achievable bidirectional rate-pairs of S1 and S2 under the given transmit power constraints at S1, S2, and R. We present the optimal relay beamforming structure as well as an efficient algorithm to compute the optimal beamforming matrix based on convex optimization techniques.

This paper studies the wireless two-way relay channel (TWRC), where two source nodes, S1 and S2, exchange information through an assisting relay node, R. It is assumed that R receives the sum signal from S1 and S2 in one timeslot, and then amplifies and forwards the received signal to both S1 and S2 in the next time-slot. By applying the principle of analogue network coding (ANC), each of S1 and S2 cancels the so-called "self-interference" in the received signal from R and then decodes the desired message. Assuming that S1 and S2 are each equipped with a single antenna and R with multi-antennas, this paper analyzes the capacity region of the ANC-based TWRC with linear processing (beamforming) at R. The capacity region contains all the achievable bidirectional rate-pairs of S1 and S2 under the given transmit power constraints at S1, S2, and R. We present the optimal relay beamforming structure as well as an efficient algorithm to compute the optimal beamforming matrix based on convex optimization techniques. Low-complexity suboptimal relay beamforming schemes are also presented, and their achievable rates are compared against the capacity with the optimal scheme.

We propose a broadcasting relay scheme in which the source-to-relay link is a multiple input multiple output (MIMO) channel and the relay-to-destination link is a broadcast channel. The operation for relay station consists of receive beamforming, amplifying and transmit beamforming (R-A-T). We study joint MIMO beamforming and power adaptation to transmit parallel data streams to multiple users with different quality-of-service (QoS) constraints. We derive the optimal solution for the beamforming weights and power adaptation at the base station and the relay station transmitters for the R-A-T scheme, and propose iterative algorithms for joint beamforming weights and power adaption. Simulation results are presented to show that the proposed iterative algorithms achieve the respective target signal-to-interference-plus-noise ratio (SINR) of mobile receivers.

A novel high data rate (HDR) Prerake DS UWB multiple access system is proposed, in which the number of taps in the Prerake filter is set to a large value while keeping the number of taps in a chip sufficiently small. Thus high data rate can be achieved via superposition of the chip waveforms, where the inter-chip interference introduced is small due to signal energy focusing. We derive the higher order moments of Multiple Access Interference (MAI) and fit the distribution of MAI using a generalized Gaussian distribution. Numerical results show that the generalized Gaussian distribution is a more appropriate statistical model for the distribution of MAI than the Gaussian distribution. Using the characteristic function (CF) method, an accurate BER formula is derived and validated by numerical results. The effect of imperfect channel estimation is discussed in detail. We highlight that under imperfect channel estimation, there is a tradeoff between the signal energy captured and the channel estimation noise introduced.

A novel high data rate (HDR) prerake DS UWB multiple access system is proposed, in which the number of taps in the prerake filter is set to a large value while keeping the number of taps in a chip sufficiently small. Hence high data rate is achieved without sacrificing signal energy captured. We derive the higher order moments of multiple access interference (MAI) and fit the distribution of MAI using a generalized Gaussian distribution. Numerical results are provided to show that generalized Gaussian distribution is a more appropriate model for the distribution of MAI. Next, accurate BER formula is derived using the characteristic function (CF) method. Numerical results show that the HDR Prerake DS UWB system outperforms the conventional partial-prerake DS UWB system.

We present a new probability density function (PDF) based on the generalized Laguerre expansion that, for the first time, completely characterize the widest range of small scale fading distributions in wireless communications. This unified PDF formula characterizes the most general case of small scale fading consisting of an arbitrary number of specular waves plus diffused power. The same formula covers all existing distributions for small scale fading, which include the Nakagami, Rician, and Rayleigh fadings, as special cases.

In this paper, the performance of Prerake DS UWB multiple access system under imperfect channel estimation is studied. The signal model of the system is derived in matrix form, which clearly shows the components of inter-chip interference, inter-symbol interference and multiple access interference. The BER formula is derived based on this signal model and validated by simulations. We highlight that the BER performance does not monotonically decrease with the growth of data rate under imperfect channel estimation. The effect of imperfect channel estimation in different cases is also discussed.

We derive exact BER formula for DS PPM UWB multiple access (MA) systems using the Characteristic Function (CF) method. All previous exact BER analysis were carried out in AWGN channels. Here we adopt the lognormal multipath fading channel model, which is more practical for real UWB applications. We derive the exact probability distribution function (PDF) of total noise using characteristic function instead of making any approximations on the PDF of interference. Numerical results clearly show that the BER obtained by CF method is more accurate than the GA method in large SNR range. We also plot the characteristic functions of the statistic decision variables to provide more insight into the numerical results.

A pre-RAKE system is proposed for the direct sequence (DS) UWB communications to capture the energy effectively in multipath channels. Based on the pre-RAKE technique, the equivalent performance of RAKE with MRC can be achieved using a receiver with only one finger. Compared to the previous research on Pre-RAKE UWB, we consider continuous chip transmission and study the effect of inter-chip interference under lognormal multipath fading channels. Numerical results are provided for cases with and without inter-chip interference to show the tradeoff between the data rate and the BER performance.

We derive exact BER formula for DS PAM UWB multiple access (MA) system using the characteristic function (CF) method. Exact BER analysis has been reported in some earlier works only for AWGN channels. In contrast to previous study, we adopt lognormal multipath fading channel model, which is more practical for real UWB applications. We use the CF method to deal with the exact probability distribution function (PDF) of total noise without making any approximations on the PDF of interference. In applications where the number of interference sources is small, we show that BER obtained by the GA method is less accurate than the CF method in large SNR range. Discussions about the BER results based on the characteristic functions are also provided.

We extend the throughput optimization technique of Qiu and Chawla (1999) for adaptive modulation, to combine power and rate adaptation in wireless cellular systems. We develop new combined power and rate control algorithms for wireless multimedia systems, in which the transmitted powers and rates of different media users are adapted based on the signal-to-interference power ratio. Using simulations, we show that with appropriately chosen power and rate limits, our proposed combined power and rate control algorithms can achieve a higher throughput when compared to previously proposed algorithms with power control only.

In this paper, we propose a multiuser detector (MUD) that is based on iterative interference cancellation (IIC), for a multiple-access multi-carrier M-ary frequency-shift-keying (MC-MFSK) system. We evaluate the error probability performance of this MC-MFSK system over Rayleigh fading channels, through both theoretical analyses and computer simulations. We show that the IIC-based MUD algorithm can be easily implemented and can improve system performance considerably.

A power control scheme with outage probability specifications is derived and studied for interference-limited wireless cellular systems in Rician/Rician fading channels. We first define a performance index, so-called signal-to-interference power ratio margin (SIRM) for each desired communication link in Rician fading channels. We also explain and discuss the relationship between the outage probability of a desired link and its SIRM. A power control scheme is then proposed to balance the outage probabilities of all the desired links and we show that applying the well-known Perron-Frobenius theory can solve such a problem. Simulation results verify the effectiveness of the proposed power control scheme. As expected, our scheme is shown to cover a previous scheme for Rayleigh fading channels as a special case.

We propose a multi-user detection (MUD) based on iterative interference cancellation (UC) for a multiple-access multi-carrier M-ary frequency-shift-keying (MC-MFSK) system. The MC-MFSK is a new multiple-access technique with the desirable properties of frequency diversity and near-far resistance. The error performance of MC-MFSK system with the IIC-based MUD algorithm is studied over noise-free and Rayleigh fading channels. Both analytical and simulation results are presented, and it will be shown that the IIC-based MUD algorithm can be easily implemented and improve system performance considerably.

This paper presents a complete analysis on the envelope probability density functions (PDF) for a new analytical model of small-scale, local area fading experienced by narrowband receivers in wireless communications. A closed-form formula of the envelope PDF is derived in terms of a series of Laguerre polynomials by using the orthogonal expansion. As shown in numerical results, this closed-form formula can be easily computed for either analytical study or computer simulation.

A new multipath interference cancellation (MIC) scheme is proposed and studied for multicode CDMA systems. The proposed MIC scheme can be divided into two sections: firstly, successive multipath interference cancellation for obtaining initial data estimation, and secondly, parallel multipath interference cancellation to further enhance the accuracy of data estimation. BER performance of the proposed MIC scheme is evaluated and compared with the parallel interference cancellation (PIC) scheme in J Chen et al. (2002) using simulation. New simulation results show that the MIC scheme achieves improvement in BER performance than the PIC scheme in J Chen et al. (2002).

We study the performance of adaptive M-ary quadrature amplitude modulation (MQAM) in wireless cellular system with Nakagami fading and log-normal shadowing. An interference-limited system is assumed and the statistic of co-channel interference is analyzed. Our analysis shows that the instantaneous signal-to-interference ratio (SIR) in cellular system with Nakagami fading and log-normal shadowing can be approximated as having the log-normal distribution. We derive the probability density function (PDF) of the instantaneous SIR and use it to evaluate the spectrum efficiency of MQAM in cellular systems. The impacts of Nakagami fading, shadowing and the target bit error rate (BER) on average throughput and average outage probability are presented and discussed.

This paper investigates capacity of CDMA system employing adaptive transmission technique under multipath fading channel. Three power control schemes with rate adaptive capability are proposed to exploit the time variation of channel fading. In all the three schemes, adaptive transmission employing BPSK is realized through adapting the processing gain (PG) to the channel conditions. A minimum PG constraint is made to ensure multiple access capability. When PG is at this minimum value, the system can have an option to adjust the transmission rate through using higher constellation QAM. For scheme 1, system capacity rather than the lower bound reported in [Kim, S.W., 1999] is obtained. System capacities for scheme 2 and 3 are analyzed and computed using numerical calculations. Our numerical results show that the proposed power control schemes 2 and 3 can obtain higher system capacities than that of ideal constant received power at the base station, for a given constant average transmission power per user.

We present analysis on the system performance of multiple-access multicarrier M-ary frequency-shift-keying (MC-MFSK) systems over Rician fading channels. A novel approach is used to exploit the fact that in multiple-access MC-MFSK system, the line-of-sight (LOS) carriers of the multiple signals can be combined into a single LOS carrier, and the multiple components of the multiple signals can combined with other Gaussian process. We derive a new probability density function (pdf) for the output of the envelope detector in MC-MFSK systems, which can be applied to compute the system performance and capacity. We also propose a chi-square approximation to the new pf for a large number of signals, which can be efficiently evaluated, and show that this approximation is very close to the exact results. Furthermore, we provide physical explanations on the effect of the number of multiple sub-carriers on the system performance.

We derive exact expressions of the symbol error rate (SER) performance of orthogonal, frequency-hopped, noncoherent M-ary frequency-shift-keying (FH/MFSK) receivers in the presence of independent multitone jamming (MTJ), as well as thermal and other wideband Gaussian noises. Both the signal tones and the multiple jamming tones are affected independently by Rician fading. Both the slow-hopping and fast-hopping systems are considered. In our derivation, we exploit the fact that the multipath components of the signal and jamming tones can be combined with the other Gaussian noises to form a single Gaussian process. Using this technique, we are able to obtain compact exact SER expressions which can be computed efficiently. From the computation results we provide physical explanations on the effects of several system parameters, such as jamming fraction, fading conditions and number of hops per symbol, on the SER performance of slow and fast FH/MFSK systems under independent MTJ.

We study generalized selection combining (GSC) schemes in independent Nakagami fading channels, where N diversity branches with the largest instantaneous signal-to-noise ratios (SNRs) are selected from the total of L (N/spl les/L) branches and then coherently or noncoherently combined. We propose two different techniques to derive the moment generating function (MGF) expressions for the GSC output SNR in generalized Nakagami fading channels, where there are distinct and noninteger fading severity parameters, as well as different average SNRs in different diversity branches. For arbitrary fading severity parameter m/sub k/, k=1, /spl middot//spl middot//spl middot/L, the MGF expression is given in a summation of N-dimensional definite integrals with the limits independent of SNR or channel parameters, and therefore can be evaluated very efficiently with numerical methods. Furthermore, for integer m/sub k/ closed-form MGF expressions are derived. Specializations of our results to Rayleigh channels and independent identically distributed (i.i.d.) Nakagami channels are presented, which are either new or equivalent to previously published results. Using the newly derived MGF expression, we provide a unified error probability analysis for many coherent and noncoherent modulation/detection schemes.

A new bit error rate (BER) expression for a noncoherent frequency-hopped binary-frequency-shift-keying (FH/BFSK) receiver in Rician channels, subjected to independent multitone and wideband noise interference, is derived. Unlike previously published analyzes, we combine the signal and jammer multipath components, the additive white Gaussian noise (AWGN), and other wideband interference as a single Gaussian process. This method leads to a BER expression which consists of only a single rather than a triple integral requiring numerical computation. We also present a new derivation of the probability density function (PDF) of the ratio of two Rician random variables, used in a previously published approximate BER analysis.

New expressions for the average level crossing rate (LCR) and average time fade duration (AFD) of the signal envelope in microcellular mobile radio channels, characterized by Nakagami (1960) fading and lognormal shadowing, so called Nakagami-lognormal (NLN) channels, are derived. New LCR and AFD are computed, and the effects of the Nakagami m factor and shadowing spread /spl sigma//sub s/ on these fade statistics are discussed. The generality of the NLN model is demonstrated by matching some LCR curves with previously reported measurement for the land mobile satellite channel, commonly described as the Rice-lognormal channels.

New expressions for the average level crossing rate (LCR) and time fade duration (TFD) of the signal envelope in microcellular mobile radio channels, characterized by Rician fading and lognormal shadowing, the so-called Rice-lognormal (RLN) channel, and by Nakagami fading and lognormal shadowing, so-called Nakagami-lognormal (RLN) channel, are presented. New LCR and TFD curves as functions of the Rice K factor, the Nakagami m factor and shadowing spread /spl sigma//sub s/ are presented and discussed. The LCR and TFD expressions for the RLN channel reduce to the published formulae for the Rayleigh-lognormal (Suzuki, 1982) channel as a special case, and for very large Rice K factor, approach those formulae obtained by Loo (1985).

New exact expressions involving hypergeometric functions are derived for the symbol-error rate (SER) of M-ary quadrature amplitude modulation (MQAM) for L branch diversity reception in Rayleigh fading and additive white Gaussian noise (AWGN). The diversity combining techniques considered are maximum ratio combining (MRC) and selection combining (SC). MRC with identical channels and dissimilar channels are analyzed.