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This paper presents an iterative interference suppression technique to cancel power amplifier (PA) distortion at the receiver. The focus is mainly on single carrier frequency division multiple access systems, and on removing the distortion created by adjacent users' power amplifier. It is assumed that the receiver has perfect knowledge of all the users' transmitter power amplifier nonlinearities....
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...
The average channel capacity for 3GPP LTE downlink multiuser Multiple Input Multiple Output (MIMO) systems is analyzed in this paper. A packet scheduler is used to exploit the available multiuser diversity in all the three physical domains (i.e., space, time and frequency). A mathematical model is established to derive the channel capacity of multiuser MIMO systems with the frequency domain packet...
In this paper, we propose a novel interference alignment (IA) scheme via convex optimization based on minimum mean square error criterion subject to individual transmit power constraints for the MIMO interference channel system. We show that transceiver under such criterion can be realized through an efficient iterative algorithm. The convergence of the proposed algorithm is discussed. Simulation...
In this paper, joint transmitter receiver filter optimization for channel equalization is investigated for a multiuser multiple input multiple output frequency selective slowly varying channel. Minimum mean square error criterion is used in the equalization under a total transmit power constraint. Because of the simplicity of the optimization of multiple access channel, channel duality is used for...
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...
We describe a channel sounding system designed for small outdoor cell (~400 meter radius) wireless channel characterization. We report on a program of path loss measurements using a 2×2 MIMO configuration and data reduction in the frequency range of 5.7-5.75 GHz. The results are based on over 10,000 independent complex frequency responses collected in residential neighborhoods in northern New Jersey...
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...
Global Navigation Satellite Systems (GNSS) can be used for navigation purposes in vehicular environments. However, the limited accuracy of GNSS makes it unsuitable for applications such as vehicle collision avoidance. Improving the positioning accuracy in vehicular networks, Cooperative Positioning (CP) algorithms have emerged. CP algorithms are based on data communication among vehicles and estimation...
A joint channel impulse response (CIR) and noise-variance estimation scheme is proposed for multi-user Multiple-Input-Multiple-Output (MIMO) Orthogonal Frequency-Division Multiplexing/Space Division Multiple Access (OFDM/SDMA) systems, which is based on the Expectation Maximization (EM) algorithm. Multiple users communicating over time-invariant and/or time-variant channels are considered in this...
In this paper we consider SC-FDE schemes (Single-Carrier with Frequency-Domain Equalization) employing multi-resolution hierarchical constellations and we consider the design of turbo receivers, implemented in the frequency-domain, for systems where we have different error protections. We present a versatile method to design the receiver that is suitable to any constellation.
This paper examines radio wave propagation in underground and subway environments from the perspective of providing digital radio with multimedia and video enhanced services (DAB/DMB) as a continuity of the same services offered above ground. To this end, a preliminary simulation framework of a DAB/DMB transmission system inside a rectangular subway tunnel is proposed. First, the received power and...
In this paper, the variational expectation-maximization (VEM) algorithm is used to provide channel estimates in a space-time decoder. The proposed estimator works for many types of space-time codes (STC), including full-rate full-diversity (FRFD) codes, Bell Laboratories layered space-time architecture (BLAST) and orthogonal STC's. The principle idea is to treat the channel coefficients as the unknown...
Almost all modern cars can be controlled remotely using a personal communicator (keyfob). However, the degree of interaction between currently available personal communicators and cars is very limited. The communication link is unidirectional and the communication range is limited to a few dozen meters. However, there are many interesting applications that could be supported if a keyfob would be able...
This paper presents a multiple-access MIMO wireless transceiver combining space- and frequency-domain spreadings with a frequency-domain block-coding strategy. Spreading across space (transmit antennas) and frequency (subcarriers) adds resilience against deep channel fades while providing space and frequency diversities, and block-coding enables multiple-access transmission. The merits of the proposed...
Re-farming of 900 MHz band into HSPA has been started and is likely to happen later with LTE. Typically operators have less than 10 MHz block of 900 MHz spectrum and therefore co-existence of two systems in that band is causing challenges. One of the major issues is the high GSM voice traffic that will remain in the GSM network. How to cope the same traffic with significantly less bandwidth for GSM?...
In this paper, we investigate the effect of imperfect channel estimation on the performance of inter-vehicular communication systems. In particular, we derive the bit error rate (BER) expression in the presence of channel estimation errors for a space-time block coded (STBC) inter-vehicular communication system based on cascaded Rayleigh fading. Our diversity analysis reveals that the underlying scheme...
Recently, multichannel protocols have been proposed and shown to significantly improve the aggregate throughput compared to single channel protocols. However, some existing proposals still suffer from low channel utilization or unfair bandwidth allocation between different flows in a multihop wireless network. In this paper, we design an asynchronous multichannel MAC called the cooperative multichannel...
In this paper, we propose a new multi-user receiver processing for PUCCH LTE that counteracts the ICI in a non-cooperative multi-cell architecture. Using the fact that the received signal in PUCCH signaling follows a constrained tensor model, a multi-user receiver based on an iterative joint channel/code estimation and symbol detection is proposed. The interest in such a challenging setting relies...
We consider the estimation of the direction of arrival (DoA) in the presence of hardware impairments that include the RF carrier frequency offsets, the phase offsets generated by an uncalibrated array, and the DC offset. The impairments model has been derived from the analysis of a hardware multiple antenna test-bed that uses direct down-conversion RF front-ends. The performance of the proposed algorithm...
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