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Recently, we proposed a joint iterative transmit/receive (Tx/Rx) minimum mean square error (MMSE) frequency-domain equalization (FDE) & inter-symbol interference (ISI) cancellation (ISIC) for single-carrier (SC) block transmissions. In this paper, we extend the previously proposed joint iterative Tx/Rx MMSE-FDE & ISIC to the SC hybrid automatic repeat request (HARQ) packet access to exploit...
In this paper, a single-carrier frequency domain adaptive antenna array (FDAAA) is proposed for the uplink transmission in cellular systems. The FDAAA algorithm will deal with co-channel interference and exploit the frequency selectivity of the channel fading jointly by using adaptive antenna array in the frequency domain. The receiver of the base station (BS) needs to adjust the AAA weight to optimize...
This article proposes a hardware triply selective Rayleigh fading channel emulator which is implemented by incorporating spatial and inter-tap correlation matrices into uncorrelated frequency-flat Rayleigh fading waveforms with a Kronecker product method. The Kronecker product of square roots of three correlation matrices are computed in real time via serial, parallel, or mixed serial-parallel computational...
In this paper, we propose and study a cooperative transmission scheme for amplify-and-forward (AF) relaying system with adaptive modulation. Unlike the conventional incremental relaying with adaptive modulation (IR-AM) scheme, which improves the spectral efficiency with the minimum usage of relaying, our proposed scheme adaptively utilizes cooperative relaying to maximize the system spectral efficiency...
Recently, substantial attention has been paid to increase the achievable rates of wireless networks using different kinds of limited channel state information (CSI) feedback. This paper aims to investigate the effect of limited CSI feedback on the achievable rates of power-limited block fading channels constrained to have limited outage probability. Considering different power allocation strategies...
Multiuser diversity is achieved by maximum C/I scheduler in both fast and slow fading scenarios. However, fairness among multiple users is not guaranteed in slow fading channel because time and frequency resource are always occupied by the user with largest signal to interference and noise ratio(SINR). Opportunistic beamforming using dumb antennas is a multiple antennas transmit technique to increase...
Robust adaptive multiuser detection schemes are developed for direct-sequence code-division multiple-access (DS-CDMA) multipath frequency-selective fading channels. Multiple access interference (MAI) and intersymbol interference (ISI) are presented in identical format in the expanded signal subspace, which provides convenience for symbol-by-symbol multiuser detection. The proposed multiuse detectors...
The performance of multihop links is studied in this contribution by both analysis and simulations, when communicating over Generalized-K (KG) fading channels. The performance metrics considered include symbol error rate (SER), outage probability, level crossing rate (LCR) and average outage duration (AOD). First, the expressions for both the SER and outage probability are derived by approximating...
This paper addresses the power allocation and relay positioning problems in Amplify-and-forward cooperative networks over Weibull fading channels. We study adaptive power allocation (PA) with fixed relay location, optimal relay location with fixed power allocation, and joint optimization of the PA and relay location under total transmit power constraint, in order to minimize the outage probability...
In this paper, we study retransmission strategies for the symmetric relaying scenario when the number of retransmissions for a data packet is limited. We propose a retransmission scheme based on superposition modulation and give the exact packet drop probability expression for it when only one retransmission is allowed. We compare the performance of the proposed retransmission scheme with retransmission...
In this paper, we consider a static cluster of base stations where joint processing is allowed in the downlink. The partial joint processing scheme is a user-centric approach where subclusters or active sets of base stations are dynamically defined for each user in the cluster. In frequency selective channels, the definition of the subclusters or active set thresholding of base stations can be frequency...
In this paper, we consider cooperative ad hoc networks and develop an analytical model to study the performance of reliable relaying schemes. In particular, we develop expressions for throughput rate and spectral efficiency for cooperating radios in a fading environment. The numerical results indicate a performance conflict between throughput rate and spectral efficiency, which depends on the underlying...
In this paper, outage probability caused by multiple interferers in Nakagami-m fading channels is studied. A novel method is proposed to derive the exact and closed form expressions of outage probability in the presence of multiple Nakagami independent cochannel interference. Unlike some previous conclusions, the method proposed in this paper is not only usable with various integer Nakagami fading...
In this paper we investigate the end-to-end performance of dual-hop fixed gain relaying systems under asymmetric fading conditions. In such conditions, the links associated with the relay network undergo different fading phenomena. In our analysis, the source-relay and the relay-destination links are subject to fading-only or composite multi-path/shadowing environments. An outage analysis of the considered...
In broadband wireless communication systems, single-carrier transmission with frequency domain equalization (SC-FDE) is regarded as an alternative modulation technique to the orthogonal frequency division multiplexing (OFDM). Compared with OFDM systems, SC-FDE has similar implementation complexity and performance. However, SC-FDE with linear equalizer will suffer from serious performance deterioration...
The pressure of the energy bill from operators and the request of the environmental protection from the governments and publics results in more urgent requirement on the energy consumption and CO2 emission. Traditionally, adaptive modulation has been proven to be an efficient solution to improve the system performance over the radio fading channels. To obtain the design insights for energy efficient...
In this paper, shadow fading (SF) in an indoor multipath environment is measured and the spatial correlation of SF is modeled statistically. To effectively extract SF from the measured field strength, we use frequency averaging (FA) method instead of spatial averaging (SA) method which has generally been used. SF is modeled as a random variable with a log-normal distribution. The spatial correlation...
In this paper, a novel method called offset modulation (OM-OFDM) is proposed, to control the peak-to-average power ratio of an OFDM signal. The theoretical bandwidth occupancy of the proposed offset modulated signal is derived. Using this bandwidth occupancy a closed form theoretical bit error rate (BER) expression for an offset modulated transmission is further derived, validated and compared to...
In this paper, we propose user grouping algorithms to provide power minimization in grouped MC-CDMA systems. Depending on the channel fading conditions, power control is utilized to minimize the total transmitted power under a bit error rate (BER) constraint. When the allocation is performed without a fair data rate requirement, we provide the optimal solution to the minimization problem. However...
This paper derives a simple general closed form expression of the bit error probability for differentially detected signals with post-detection equal gain combining in additive white Gaussian noise and slow frequency nonselective fading channels. The derived expression is then used to study the performance of Gaussian minimum shift keying (GMSK) and quadrature Differential phase sift keying (QDPSK)...
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