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Channel Estimation and Hybrid Precoding for Millimeter Wave Cellular Systems
TLDR
An adaptive algorithm to estimate the mmWave channel parameters that exploits the poor scattering nature of the channel is developed and a new hybrid analog/digital precoding algorithm is proposed that overcomes the hardware constraints on the analog-only beamforming, and approaches the performance of digital solutions.
Limited Feedback Hybrid Precoding for Multi-User Millimeter Wave Systems
TLDR
Analytical and simulation results show that the proposed techniques offer higher sum rates compared with analog-only beamforming solutions, and approach the performance of the unconstrained digital beamforming with relatively small codebooks.
Pilot-Assisted Time-Varying Channel Estimation for OFDM Systems
TLDR
This paper proposes novel channel estimators to combat both the noise and the out-of-band interference in orthogonal frequency-division multiplexing (OFDM) systems.
Optimal training design for MIMO OFDM systems in mobile wireless channels
TLDR
It is shown that the optimal pilot sequences derived in this paper outperform both the orthogonal and random pilot sequences and that a considerable gain in signal-to-noise ratio (SNR) can be obtained by using the RLS algorithm, especially in slowly time-varying channels.
Spectrum Sensing for Cognitive Radio : State-of-the-Art and Recent Advances
TLDR
Cognitive radio is introduced to exploit underutilized spectral resources by reusing unused spectrum in an opportunistic manner and the idea of using learning and sensing machines to probe the radio spectrum was envisioned several decades earlier.
Orthogonal design of unitary constellations for uncoded and trellis-coded noncoherent space-time systems
TLDR
Based on the sequence pairwise error analysis, two simple parameters are identified to quantify the asymptotic error performance, which enables us to compare among different TCM schemes or uncoded alternatives.
Sparsity-Cognizant Total Least-Squares for Perturbed Compressive Sampling
TLDR
Analysis and simulations demonstrate the practical impact of S-TLS in calibrating the mismatch effects of contemporary grid-based approaches to cognitive radio sensing, and robust direction-of-arrival estimation using antenna arrays, as well as formulating and solving (regularized) TLS optimization problems under sparsity constraints.
Compressive Wideband Power Spectrum Estimation
TLDR
A solution is first presented based on a periodic sampling procedure and a simple least-squares reconstruction method that is able to recover the unknown power spectrum of a wide-sense stationary signal from the obtained sub-Nyquist rate samples and the statistical properties of the estimated power spectrum.
Noncoherent ultra-wideband systems
TLDR
An overview of the state of the art of recent research activities in noncoherent ultra-wideband receiver front ends is provided with a focus on architectures that perform the initial signal processing tasks in the analog domain, such that the receiver does not need to sample the UWB received signals at Nyquist rate.
Simple equalization of time-varying channels for OFDM
TLDR
A block minimum mean-squared error (MMSE) equalizer for orthogonal frequency-division multiplexing (OFDM) systems over time-varying multipath channels is presented and turns out to be smaller than a serial MMSE equalizer characterized by a similar performance.
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