101 research outputs found
Two Rapid Power Iterative DOA Estimators for UAV Emitter Using Massive/Ultra-massive Receive Array
To provide rapid direction finding (DF) for unmanned aerial vehicle (UAV)
emitter in future wireless networks, a low-complexity direction of arrival
(DOA) estimation architecture for massive multiple input multiple output (MIMO)
receiver arrays is constructed. In this paper, we propose two strategies to
address the extremely high complexity caused by eigenvalue decomposition of the
received signal covariance matrix. Firstly, a rapid power-iterative rotational
invariance (RPI-RI) method is proposed, which adopts the signal subspace
generated by power iteration to gets the final direction estimation through
rotational invariance between subarrays. RPI-RI makes a significant complexity
reduction at the cost of a substantial performance loss. In order to further
reduce the complexity and provide a good directional measurement result, a
rapid power-iterative Polynomial rooting (RPI-PR) method is proposed, which
utilizes the noise subspace combined with polynomial solution method to get the
optimal direction estimation. In addition, the influence of initial vector
selection on convergence in the power iteration is analyzed, especially when
the initial vector is orthogonal to the incident wave. Simulation results show
that the two proposed methods outperform the conventional DOA estimation
methods in terms of computational complexity. In particular, the RPIPR method
achieves more than two orders of magnitude lower complexity than conventional
methods and achieves performance close to CRLB. Moreover, it is verified that
the initial vector and the relative error have a significant impact on the
performance of the computational complexity
A New Heterogeneous Hybrid MIMO Receive Structure of Rapidly Eliminating DOA Ambiguity
Massive multiple input multiple output(MIMO)-based fully-digital receive
antenna arrays eventuate a huge amount of circuit costs and complexity to
direction of arrival(DOA) estimation, which is hard to satisfy the needs of
high precision and low cost in future green wireless communication. To address
this challenge, a novel heterogeneous hybrid MIMO receiver is proposed in this
paper and a high performance DOA estimator called heterogeneous cross-minimum
distance (HCMD) is developed based on the structure. The antenna arrays are
first divided into multiple groups, and each group adopts a different hybrid
structure. The virtual antenna arrays of these groups are then used for DOA
estimation to generate multiple candidate angle sets, where each set contains a
unique true solution and multiple pseudo-solutions. Finally, the cross-distance
minimization method is applied to the multiple candidate angle sets to select
the corresponding true solution for each group, and the final DOA estimation is
given by combining the multiple true solutions. Simulation results show that as
the number of antennas tends to large-scale, the proposed method can rapidly
find the true solution for each group and achieve excellent estimation
performance
DOA Estimation for Hybrid Massive MIMO Systems using Mixed-ADCs: Performance Loss and Energy Efficiency
Due to the power consumption and high circuit cost in antenna arrays, the
practical application of massive multipleinput multiple-output (MIMO) in the
sixth generation (6G) and future wireless networks is still challenging.
Employing lowresolution analog-to-digital converters (ADCs) and hybrid analog
and digital (HAD) structure is two low-cost choice with acceptable performance
loss. In this paper, the combination of the mixedADC architecture and HAD
structure employed at receiver is proposed for direction of arrival (DOA)
estimation, which will be applied to the beamforming tracking and alignment in
6G. By adopting the additive quantization noise model, the exact closedform
expression of the Cramer-Rao lower bound (CRLB) for the HAD architecture with
mixed-ADCs is derived. Moreover, the closed-form expression of the performance
loss factor is derived as a benchmark. In addition, to take power consumption
into account, energy efficiency is also investigated in our paper. The
numerical results reveal that the HAD structure with mixedADCs can
significantly reduce the power consumption and hardware cost. Furthermore, that
architecture is able to achieve a better trade-off between the performance loss
and the power consumption. Finally, adopting 2-4 bits of resolution may be a
good choice in practical massive MIMO systems.Comment: 11 pages, 7 figure
Three more Decades in Array Signal Processing Research: An Optimization and Structure Exploitation Perspective
The signal processing community currently witnesses the emergence of sensor
array processing and Direction-of-Arrival (DoA) estimation in various modern
applications, such as automotive radar, mobile user and millimeter wave indoor
localization, drone surveillance, as well as in new paradigms, such as joint
sensing and communication in future wireless systems. This trend is further
enhanced by technology leaps and availability of powerful and affordable
multi-antenna hardware platforms. The history of advances in super resolution
DoA estimation techniques is long, starting from the early parametric
multi-source methods such as the computationally expensive maximum likelihood
(ML) techniques to the early subspace-based techniques such as Pisarenko and
MUSIC. Inspired by the seminal review paper Two Decades of Array Signal
Processing Research: The Parametric Approach by Krim and Viberg published in
the IEEE Signal Processing Magazine, we are looking back at another three
decades in Array Signal Processing Research under the classical narrowband
array processing model based on second order statistics. We revisit major
trends in the field and retell the story of array signal processing from a
modern optimization and structure exploitation perspective. In our overview,
through prominent examples, we illustrate how different DoA estimation methods
can be cast as optimization problems with side constraints originating from
prior knowledge regarding the structure of the measurement system. Due to space
limitations, our review of the DoA estimation research in the past three
decades is by no means complete. For didactic reasons, we mainly focus on
developments in the field that easily relate the traditional multi-source
estimation criteria and choose simple illustrative examples.Comment: 16 pages, 8 figures. This work has been submitted to the IEEE for
possible publication. Copyright may be transferred without notice, after
which this version may no longer be accessibl
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