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In this paper, a low complexity blind synchronization algorithm is proposed for ultra wideband (UWB) communication systems in the multipath environment. Using the first order statistics of the received signal, the proposed algorithm is carried out without aided data. The synchronization parameter and nuisance ones are separated from each other on account of the structure of the Vandermonde matrix,...
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 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...
In this paper, we propose a decoupled root-MUSIC algorithm adapted to the multidimensional harmonic model, which is widely used in MIMO channel sounding. The optimization criterion of the proposed algorithm is based on multidimensional orthogonal condition testings between a tensor steering manifold parameterized by the parameters of interest and a set of orthogonal projectors associated with each...
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 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...
We propose a new simple and accurate approach to estimate the Doppler spread which is a key parameter in the context of wireless communication systems. This new approach stems from the well known fact that the crosscorrelation of the channel is a weighted summation of monochromatic plane waves (or inverse Fourier transform of its power spectral density). In the case of Doppler spread, these plane...
In this paper, we propose a robust novel approach with closed-form estimator for object tracking based on a non-linear measurement model over time from a single sensor with arbitrary noise degradation. Relying on the widely-used dynamic motion model for arbitrary moving targets, tracking of moving objects can be formulated using received signal strength (RSS) measurements. We provide a closed-form...
An iterative joint decoding algorithm for data gathering wireless sensor networks is proposed in where the correlation between sensorspsila data is considered as a global code and iterative decoding is performed by concatenating the global decoder with the decoder of error correcting code applied to encode sensors observations. We apply this algorithm for sensor networks with binary CEO model where...
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...
This paper analyzes the connectivity of wireless ad hoc networks in both a non-cooperative scheme and a cooperative scheme. Assuming that nodes are randomly distributed with a Poisson process, the probability of full connectivity in a system can be raised by increasing the number of connectional trials at each node. Even though an infinite number of trials guarantee full connectivity in a system,...
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,...
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...
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...
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 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...
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...
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...
This paper presents an enhanced permeable layer mechanism useful for reliable packetized multimedia transmission. Packet header recovery at various protocol layers using MAP estimation is the cornerstone of the proposed solution. The available intra-layer and inter-layer header correlation is used to define a reduced set of header configurations for further processing. The best candidate is then obtained...
The performance of the carrier sense multiple access/collision avoidance (CSMA/CA) protocol under the presence of carrier sensing errors is analyzed. Two types of carrier sensing errors, false alarm and miss detection, are considered, and their impact on system performance is analyzed using a new CSMA/CA model based on a Markov chain capturing the sensing errors at the physical layer. The throughput...
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