30 research outputs found
Low computational complexity for optimizing energy efficiency in mm-wave hybrid precoding system for 5G
Millimeter-wave (mm-wave) communication is the spectral frontier to meet the anticipated
significant volume of high data traffic processing in next-generation systems. The primary challenges in
mm-wave can be overcome by reducing complexity and power consumption by large antenna arrays for
massive multiple-input multiple-output (mMIMO) systems. However, the circuit power consumption is
expected to increase rapidly. The precoding in mm-wave mMIMO systems cannot be successfully achieved
at baseband using digital precoders, owing to the high cost and power consumption of signal mixers and
analog-to-digital converters. Nevertheless, hybrid analog–digital precoders are considered a cost-effective
solution. In this work, we introduce a novel method for optimizing energy efficiency (EE) in the upper-bound
multiuser (MU) - mMIMO system and the cost efficiency of quantized hybrid precoding (HP) design.
We propose effective alternating minimization algorithms based on the zero gradient method to establish
fully-connected structures (FCSs) and partially-connected structures (PCSs). In the alternating minimization
algorithms, low complexity is proposed by enforcing an orthogonal constraint on the digital precoders
to realize the joint optimization of computational complexity and communication power. Therefore, the
alternating minimization algorithm enhances HP by improving the performance of the FCS through
advanced phase extraction, which involves high complexity. Meanwhile, the alternating minimization
algorithm develops a PCS to achieve low complexity using HP. The simulation results demonstrate that the
proposed algorithm for MU - mMIMO systems improves EE. The power-saving ratio is also enhanced for
PCS and FCS by 48.3% and 17.12%, respectively
Mobile optical wireless system using fast beam Angle, delay and power adaptation with angle diversity receivers
Low computational complexity for optimizing energy efficiency in Mm-wave hybrid precoding system for 5G
Millimeter-wave (mm-wave) communication is the spectral frontier to meet the anticipated
significant volume of high data traffic processing in next-generation systems. The primary challenges in
mm-wave can be overcome by reducing complexity and power consumption by large antenna arrays for
massive multiple-input multiple-output (mMIMO) systems. However, the circuit power consumption is
expected to increase rapidly. The precoding in mm-wave mMIMO systems cannot be successfully achieved
at baseband using digital precoders, owing to the high cost and power consumption of signal mixers and
analog-to-digital converters. Nevertheless, hybrid analog–digital precoders are considered a cost-effective
solution. In this work, we introduce a novel method for optimizing energy efficiency (EE) in the upper-bound
multiuser (MU) - mMIMO system and the cost efficiency of quantized hybrid precoding (HP) design.
We propose effective alternating minimization algorithms based on the zero gradient method to establish
fully-connected structures (FCSs) and partially-connected structures (PCSs). In the alternating minimization
algorithms, low complexity is proposed by enforcing an orthogonal constraint on the digital precoders
to realize the joint optimization of computational complexity and communication power. Therefore, the
alternating minimization algorithm enhances HP by improving the performance of the FCS through
advanced phase extraction, which involves high complexity. Meanwhile, the alternating minimization
algorithm develops a PCS to achieve low complexity using HP. The simulation results demonstrate that the
proposed algorithm for MU - mMIMO systems improves EE. The power-saving ratio is also enhanced for
PCS and FCS by 48.3% and 17.12%, respectively.ye
Long-baseline, sub-decimeter kinematic GPS positioning of moving object, with potential application to monitor ocean surface wave
Precise relative kinematic positioning of moving platforms using GPS carrier phase
observables has numerous applications. One prominent application is utilization of highly
stabilized GPS technology mounted on the buoy, which is specially designed for detecting
tsunami wave at open sea. The essential point of this research is to investigate a potential use of a
GPS tsunami buoy for the purpose of tsunami early warning system with long-baseline kinematic
GPS processing method.
The rule of thumb GPS positioning concept, GPS position results are affected by. baseline
length mostly due to de-correlation of atmospheric errors. As baseline lengths increase, position
results degrade due to the difficulty to correctly fix the cariier phase ambiguity to its integer
value. carrier phase fixed ambiguity solutions are more accurate that float arnbiguify solutions. It
is generally accepted that carrier phase can be successfUlly fixed for baselines of up to 10 km.
After that, fixing ambiguities becomes more difficult and risky. It would be certainty more
advantageous to have a reliable float solution rather than an unreliable fixed solution.
In this study, we have developed a new quasi-real time long-baseline kinematic analysis
method using dual-frequency carrier phase with floated ambiguities, implemented in the Bernese
GPS Software Version 5.0. We demonstrate that early detection of a damaging tsunami can be
achieved by tracking the anomalous changes in sea surface height. The movements of a GPS
buoy relative to a base station with baseline length of 500 km have been monitored in quasi-real
time mode, and the tsunami waves caused by the 5th September 2004 Off Kii Peninsula
earthquake, Japan, have been successful detected as they went by, even though these were only 15 cm high. The filtered record of the solution closely resembles that of short baseline, with
RMS of 3.4 cm over 2.5 hours.
To test the robustness of our Iong-baseline kinematic GPS method under various
meteorological, we conducted the GPS tsunami buoy data analysis continuously for 8 days to
monitor the motion of the buoy. The average scatterings of GPS buoy heights by the low-pass
filtered 1 -Hz positioning result after tidal correction are about 3.4 cm and 1.2 cm under both
typhoon and calm weather conditions. This accuracy is precise enough to be applicable to a
tsunami early warning system. Since our long-baseline kinematic GPS analysis is effective to a
long baseline up to 500 km, we can place a GPS buoy far offshore, which ensures an adequate
evacuation time even, for people living on the coast
Digit-Serial DA-Based Fixed-Point RNNs: A Unified Approach for Enhancing Architectural Efficiency
The next crucial step in artificial intelligence involves integrating neural network models into embedded and mobile systems. This requires designing compact and energy-efficient neural network models in silicon for optimized performance. This article introduces a unified approach for enhancing the architectural efficiency of long short-term memory (LSTM) recurrent neural networks (RNNs). Precisely, two new structures (I and II) based on the two’s complement (TC) digit-serial distributed arithmetic (DSDA) technique are presented. The block-circulant matrix–vector multiplications (MVMs) and element-wise multiplications (EWMs) are formulated using TC DSDA. In addition, a fixed-point (FxP) training procedure for quantized LSTM RNNs is considered and validated for speech recognition tasks. Both structures leverage the circular rotation of weights and generate partial products with input digit slices. A new partial-product generator (PPG) and partial-product selector (PPS) designed to work with both unsigned and signed digits is introduced. In Structure I, a nonpipelined MVM is realized with a few PPGs and PPSs, followed by a shift-accumulate unit (SAU). Conversely, in Structure II, a suitably chosen depth-pipelined MVM is achieved with multiple PPGs and PPSs, followed by a shift-to-add tree (SAT). A critical path delay (CPD) analysis for both the proposed structures is also presented. Compared with previous works, post-synthesis results on 28 -nm fully depleted silicon-on-insulator (FDSOI) technology reveal that for a model size of 128 × 128 , Structures I and II provide 39.87% , 95.63% , and 30.95% , 91.18% more area and energy efficiencies, respectively
An Efficient Scheme for Acoustic Echo Canceller Implementation Using Offset Binary Coding
This article presents an efficient design and implementation scheme for a low-area and low-power acoustic echo canceller. The design employs the block least mean square algorithm-based adaptive filter (ADF) using offset binary coding. The proposed approach first formulates the ADF by splitting the matrix–vector multiplication into smaller ones. Each of them is then realized with lookup tables and shift accumulate units with offset terms. An efficient scheme is suggested to update the offset terms from the corresponding lookup tables. In addition, a novel optimization scheme is proposed based on the grouping of partial products (PPs) and moving windows. The PPs are generated in two parallel styles using adders, multiplexers, and registers. The optimized architecture is shared to compute both the filter output and coefficient increment terms in every iteration. The fixed-point quantization model for the architecture is also discussed. Accuracy measure is defined to characterize the proposed design and compare it with the Cramer–Rao lower bound. Simulations are carried out to evaluate the performance of the proposed design. Field-programmable gate array implementation results and application-specific integrated circuit synthesis show that the proposed design outperforms the state-of-the-art architectures
An Efficient Scheme for Acoustic Echo Canceller Implementation Using Offset Binary Coding
Detecting DDoS Threats Using Supervised Machine Learning for Traffic Classification in Software Defined Networking
Software-Defined Networking (SDN) is a promising solution for large-scale network management that offers extensive opportunities for optimization. However, the centralized control inherent in SDN also exposes networks to security threats, notably Distributed Denial of Service (DDoS) attacks. To address these challenges, machine learning (ML) techniques have emerged as potent tools for anomaly detection and mitigation. This paper proposes a novel approach for traffic classification within SDN environments that distinguishes between benign and malicious traffic using supervised ML techniques. This study introduces a unique dataset tailored for DDoS attack detection, overcoming the limitations of existing datasets, such as unrealistic topologies and lack of public availability. Benchmarking against the CICDDoS2019 dataset validated the efficacy and relevance of the custom dataset. This research has significant implications for real-world applications, offering improved capabilities for detecting and mitigating DDoS attacks in SDN infrastructure. Experimental results demonstrated the effectiveness of the proposed random forest model, achieving a remarkable accuracy of 98.97% and a minimal False Alarm Rate (FAR) of 0.023. These findings underscore the potential of ML-based approaches in enhancing network security and resilience against DDoS attacks in SDN environments, paving the way for future advancements in network-defense strategies
Two Distributed Arithmetic Based High Throughput Architectures of Non-Pipelined LMS Adaptive Filters
Distributed arithmetic (DA) is an efficient look-up table (LUT) based approach. The throughput of DA based implementation is limited by the LUT size. This paper presents two high-throughput architectures (Type I and II) of non-pipelined DA based least-mean-square (LMS) adaptive filters (ADFs) using twos complement (TC) and offset-binary coding (OBC) respectively. We formulate the LMS algorithm using the steepest descent approach with possible extension to its power-normalized LMS version and followed by its convergence properties. The coefficient update equation of LMS algorithm is then transformed via TC DA and OBC DA to design and develop non-pipelined architectures of ADFs. The proposed structures employ the LUT pre-decomposition technique to increase the throughput performance. It enables the same mapping scheme for concurrent update of the decomposed LUTs. An efficient fixed-point quantization model for the evaluation of proposed structures from a realistic point-of-view is also presented. It is found that Type II structure provides higher throughput than Type I structure at the expense of slow convergence rate with almost the same steady-state mean square error. Unlike existing non-pipelined LMS ADFs, the proposed structures offer very high throughput performance, especially with large order DA base units. Furthermore, they are capable of performing less number of additions in every filter cycle. Based on the simulation results, it is found that 256th order filter with 8th order DA base unit using Type I structure provides 9 :41 x higher throughput while Type II structure provides 16 :68 x higher throughput as compared to the best existing design. Synthesis results show that 32nd order filter with 8th order DA base unit using Type I structure achieves 38 :76% less minimum sampling period (MSP), occupies 28 :62% more area, consumes 67 :18% more power, utilizes 49 :06% more slice LUTs and 3 :31% more flip-flops (FFs), whereas Type II structure achieves 51 :25% less MSP, occupies 21 :42% more area, consumes 47 :84% more power, utilizes 29 :10% more slice LUTs and 1 :47% fewer FFs as compared to the best existing design.Funding Agencies|Umm Al-Qura University [22UQU4350362DSR01]; University of Tabuk [S-1442-0151]</p
