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To combine the high power efficiency of Continuous Phase Modulation (CPM) with either high spectral efficiency or enhanced performance in low signal to noise conditions, some authors have proposed to introduce CPM in a MIMO frame, by using Space Time Codes (STC). In this paper, we address the code design problem of Space Time Block Codes combined with CPM and introduce a new design criterion based...
We study the problem of joint transmit and receive filters optimization in a frequency selective, multiple-input multiple-output setup. The information about the channel at the transmitter is imperfect and belongs to a specified uncertainty set, defined by bounding the norm of the error transfer function. The framework for a robust optimization of the system, with mean-square-error (MSE) as the performance...
This article introduces a 3D space-time-space block code for future terrestrial digital TV in single frequency networks. The proposed 3D code is based on a double layer structure designed for inter-cell and intra-cell space time coded transmissions. We show that this new structure is particularly efficient for SFN environments regardless of the location of the receiver. It is then suitable for fixed,...
Reduced-rank code division multiple access (CDMA) multi-user detection has received a lot of attention recently. The output SINR provided by a reduced-rank receiver depends on the filter rank and is confined between the SINRs of the single user matched filter (SUMF) and the minimum mean squared error (MMSE) receiver. In packet CDMA data networks like HSDPA, the measure of performance is the throughput...
We consider a new source coding problem motivated by the following distributed estimation task in a clustered sensor network. Suppose there are multiple uncorrelated signal sources in the field that we are interested in, however, these sources cannot be directly observed by the sensors. Sensors within each cluster communicate directly with their corresponding cluster-head (CH) to report their observations,...
Energy efficient transmission is of vital importance in the design of wireless sensor networks (WSN).Minimizing the sum of energy consumption of all sensor nodes in the network may lead to some nodes with non-rechargeable batteries running out of energy quickly. In this paper, we consider to maximize the time until the first node fails in the network, namely, the network lifetime. Transmission schemes...
In this paper, we consider a multiple antenna broadcast scenario with multiple non-cooperative users under the assumption of imperfect channel state information. Under an instantaneous transmit power constraint, vector perturbation precoding requires that the users be continuously informed about the adaptive power scaling factor used at the transmit side. To overcome this limitation, we propose a...
Transmission techniques for the wireless multi-antenna broadcast channel often require that the receivers feed back their channel state information (CSI) to the transmitter. In this paper, we propose a limited feedback method to approximate zero-forcing beamforming. Each user feeds back quantized information about channel direction and a deterministic lower bound on its signal-to-interference-plus-noise...
We present a general framework for the minimization of a function which is parametrized by a set of covariance matrices over a constraint set. Since all covariance matrices have to obey the property of being positive semidefinite, this characteristic has to be reflected in the constraint set. In addition, the sum of all traces of the covariance matrices shall be upper bounded. Using a preconditioned...
Traditional information-theoretic approaches to study channel feedback assume that the information is sent from the receiver to the transmitter via an ideal (instantaneous high-rate and error-free) feedback link. This paper investigates the problem of reliable communication over non-ergodic memoryless (stationary) channels using non-errorfree feedback links. We first provide a coding theorem showing...
Time and frequency offsets can cause severe degradation in the performance of any OFDM-based System. Therefore synchronization procedures are necessary for the proper function of a receiver. In OFDMA, where different users share the available subcarriers, synchronization becomes an arduous task. Synchronization errors as far as the uplink transmission is concerned may cause intolerable Multiple Access...
Recently, distributed space-time coding over half duplex wireless relay networks has been proposed to achieve higher diversity at the receiver. The use of orthogonal and quasi-orthogonal designs in such relay networks has the advantage of providing maximum diversity at a low decoding complexity. However, similar to their originating space-time codes, these designs are restricted in terms of rate and...
This paper presents a low-complexity reduced-rank approach to adaptive linearly constrained minimum variance (LCMV) beamforming. The proposed reduced-rank scheme is based on a constrained joint iterative optimization of adaptive filters according to the minimum variance criterion. The constrained joint iterative optimization procedure adjusts the parameters of a bank of full-rank adaptive filters...
The design of channel quantization codebooks for correlated broadcast channels with limited feedback is addressed. A design criterion that effectively exploits the cell statistics is proposed, based on minimizing the average sum-rate distortion in a system with joint linear beamforming and multiuser scheduling. The proposed average distortion function is optimized by generating a set of quantization...
This paper provides a performance comparison of multiple-input multiple-output (MIMO) demodulators for bit-interleaved coded modulation (BICM) systems with non-iterative demodulation and decoding. We propose to use the capacity of an equivalent ldquomodulationrdquo channel as a performance measure that has the advantage of not depending on the outer error correcting code. Based on this approach, we...
Spatial multiplexing is a common technique for multiple-input multiple-output (MIMO) communications that independent information streams are sent over different antennas. The precoder design based on the channel state information (CSI) can process the transmitting symbol before transmission. However, the spatial multiplexing is still sensitive to the ill-conditioning of the channel matrix. The conventional...
In this work several methods for the location of legacy GSM handsets are compared. These methods use data available in the mobile station measurement report - communication channel server identity, received power levels from the serving and neighbor cells, received signal quality - and time alignment with the server. It is discussed how these parameters can be used for mobile station positioning....
In this paper, we present a new algorithm of blind frame synchronization and phase offset estimation that can be applied to any digital transmission scheme using a channel coding with a binary phase shift keying (BPSK) modulation. The estimator is based on the calculation of the syndrome elements of a received codeword obtained using the parity check matrix of the code. After presenting the proposed...
We consider carrier frequency offset (CFO) estimation for single-carrier and single-user transmission over a frequency-selective channel. When training is solely devoted to frequency synchronization, it is important to design the training to optimize CFO estimation performance. In this paper we exhibit the training sequence that minimizes the Cramer-Rao bound associated with the carrier frequency...
In certain OFDM-based communication systems for which data demodulation is not the final goal, it is often of interest to estimate the signal-to-noise power ratio (SNR) from observed samples that are taken asynchronously. Examples include link quality monitoring in broadcast repeaters and spectrum sensing in cognitive radio systems. We examine the structure of the Maximum Likelihood estimate for this...
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