Browsing by Author "Belostotski, L"

Now showing 1 - 4 of 4

item: Conference-Full-text
Delta-sigma noise shaping in 2d spacetime for uniform linear aperture array receivers
(IEEE, 2016-04) Handagala, S; Madanayake, A; Belostotski, L; Bruton, LT; Jayasekara, AGBP; Bandara, HMND; Amarasinghe, YWR
A multi-dimensional noise-shaping method based on delta-sigma modulation has been proposed. This method extends delta-sigma modulation into the two-dimensional (2-D) case (space, time). The proposed noise-shaping method employs lossless discrete integrators for realization in microwave and mmwave array processing systems. The paper shows that 2-D noiseshaping reduces the spectral overlap of a desired array signal with that of noise. By reducing the overlap of the ROSs, 2- D filtering can be used to improve the overall noise figure of the array receiver. A noise figure improvement of 2.6 dB could be simulated for a 4-times spatially over-sampled array with 65 simulated elements for an input signal to noise ratio of 10 dB and LNA noise figure of 5 dB. Simulation results based on wideband signals on 33, 65, 129 and 257 element antenna arrays with 2, 4 and 8 times oversampling show the potential capability of the proposed system in improving overall noise figure. Although mathematical modeling shows potential improvements in receiver noise figure, RF integrated circuit realizations are challenging and have not been attempted yet.
item: Conference-Abstract
Design methodology of an analog 9-beam squint-free wideband IF multi-beamformer for mmW applications
(2017) Ariyarathna, V; Udayanga, N; Madanayake, A; Perera, SM; Belostotski, L; Cintra, RJ
An intermediate frequency (IF) squinting-free multi-beamforming method is proposed for multi-antenna systems. The proposed approach uses a low-complexity factorization of a true-time-delay (TTD) multi-beam matrix, which is proposed to be realized using an analog integrated circuits approach. A TTD realization of multi-beams at intermediate frequency is achieved following amplification and synchronous down-conversion via the proposed Delay Vandermonde Matrix (DVM) in which matrix elements correspond to the compound phase compensation required for squint-free steering of each radio-frequency beam. True-time-delays are proposed to be efficiently realized on-chip by applying a sparse factorization to the DVM, which leads to a low circuit complexity implementation requiring a significantly lower number of TTD blocks and phase compensations compared to an equivalent direct implementation for a given N number of beams. The proposed method, for 9- beams, leads to a 60% reduction of analog integrated circuit based TTD blocks and phase compensators. The TTD blocks can be realized on chip using active-RC based integrated analog all-pass filters. The proposed multi-beam algorithm and circuit structure is simulated within the frequency range 55-65 GHz to demonstrate squinting-free wide-band multi-beams at millimeter wave carrier frequencies for emerging 5G applications.
item: Conference-Abstract
An Overview of multi-dimensional RF signal processing for array receivers
Madanayake, A; Wijenayake, C; Belostotski, L; Bruton, LT
In this review paper, recent advancements in multidimensional (MD) spatio-temporal signal processing for highlydirectional radio frequency (RF) antenna array based receivers are discussed. MD network-resonant beamforming filters having infinite impulse response (IIR) and recursive spatio-temporal signal flow graphs are reviewed. The concept of MD networkresonant pre-filtering is described as a modification to existing phased/timed array beamforming back-ends to achieve improved side-lobe performance in the array pattern, leading to better interference rejection capabilities. Both digital and analog signal processing models are described in terms of their system transfer functions and signal flow graphs. Example MD frequency response and RF antenna array pattern simulations are presented.
item: Conference-Full-text
An Overview of Multi-Dimensional RF Signal Processing for Array Receivers
(2015-08-03) Madanayake, A; Wijenayake, C; Belostotski, L; Bruton, Len T
In this review paper, recent advancements in multidimensional (MD) spatio-temporal signal processing for highlydirectional radio frequency (RF) antenna array based receivers are discussed. MD network-resonant beamforming filters having infinite impulse response (IIR) and recursive spatio-temporal signal flow graphs are reviewed. The concept of MD networkresonant pre-filtering is described as a modification to existing phased/timed array beamforming back-ends to achieve improved side-lobe performance in the array pattern, leading to better interference rejection capabilities. Both digital and analog signal processing models are described in terms of their system transfer functions and signal flow graphs. Example MD frequency response and RF antenna array pattern simulations are presented.