WRHT: Efficient All-reduce for Distributed DNN Training in Optical Interconnect System

Communication efficiency plays an important role in accelerating the distributed training of Deep Neural Networks (DNN). All-reduce is the key communication primitive to reduce model parameters in distributed DNN training. Most existing all-reduce algorithms are designed for traditional electrical interconnect systems, which cannot meet the communication requirements for distributed training of large DNNs. One of the promising alternatives for electrical interconnect is optical interconnect, which can provide high bandwidth, low transmission delay, and low power cost. We propose an efficient scheme called WRHT (Wavelength Reused Hierarchical Tree) for implementing all-reduce operation in optical interconnect system, which can take advantage of WDM (Wavelength Division Multiplexing) to reduce the communication time of distributed data-parallel DNN training. We further derive the minimum number of communication steps and communication time to realize the all-reduce using WRHT. Simulation results show that the communication time of WRHT is reduced by 75.59%, 49.25%, and 70.1% respectively compared with three traditional all-reduce algorithms simulated in optical interconnect system. Simulation results also show that WRHT can reduce the communication time for all-reduce operation by 86.69% and 84.71% in comparison with two existing all-reduce algorithms in electrical interconnect system.Comment: This paper is under the submission of GLOBECOM 202

Sustainable economic development : concept, principles and management from Islamic perspective

The basic concern of development in Islamic economic system is on human welfare. This is in line with the very basic objective of Islamic jurisprudence (Shari’ah ) which puts important to the welfare of the people and their relief from hardship. Economic development should be consistent with this central objective of shari`ah. The center for development process in Islam relies on man as an economic agent. It is man to be educated on the entire development process by integrating sosial development, economic development and environmental conservation and protection. This paper attempts to explain the concept, principles and management of sustainable economic development from Islamic perspective. The paper would start by defining the concept of sustainable economic development and development goals. Next, the Islamic principles for sustainable economic development would be discussed, followed by the discussion on the management of sustainable economic development from Islamic perspective. In conclusion, the paper strongly suggests the economic development process to fully adhere to the Islamic principles as the key for sustainable development which covers both the material and non-material aspects of life. Keywords: Sustainable development, Economic development, management, Islamic economics, economic syste

Cooperative Symbol-Based Signaling for Networks with Multiple Relays

Wireless channels suffer from severe inherent impairments and hence reliable and high data rate wireless transmission is particularly challenging to achieve. Fortunately, using multiple antennae improves performance in wireless transmission by providing space diversity, spatial multiplexing, and power gains. However, in wireless ad-hoc networks multiple antennae may not be acceptable due to limitations in size, cost, and hardware complexity. As a result, cooperative relaying strategies have attracted considerable attention because of their abilities to take advantage of multi-antenna by using multiple single-antenna relays. This study is to explore cooperative signaling for different relay networks, such as multi-hop relay networks formed by multiple single-antenna relays and multi-stage relay networks formed by multiple relaying stages with each stage holding several single-antenna relays. The main contribution of this study is the development of a new relaying scheme for networks using symbol-level modulation, such as binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK). We also analyze effects of this newly developed scheme when it is used with space-time coding in a multi-stage relay network. Simulation results demonstrate that the new scheme outperforms previously proposed schemes: amplify-and-forward (AF) scheme and decode-and-forward (DF) scheme

Development of a dc-ac power conditioner for wind generator by using neural network

This project present of development single phase DC-AC converter for wind generator application. The mathematical model of the wind generator and Artificial Neural Network control for DC-AC converter is derived. The controller is designed to stabilize the output voltage of DC-AC converter. To verify the effectiveness of the proposal controller, both simulation and experimental are developed. The simulation and experimental result show that the amplitude of output voltage of the DC-AC converter can be controlled

Joint Hybrid Precoder and Combiner Design for mmWave Spatial Multiplexing Transmission

Millimeter-wave (mmWave) communications have been considered as a key technology for future 5G wireless networks because of the orders-of-magnitude wider bandwidth than current cellular bands. In this paper, we consider the problem of codebook-based joint analog-digital hybrid precoder and combiner design for spatial multiplexing transmission in a mmWave multiple-input multiple-output (MIMO) system. We propose to jointly select analog precoder and combiner pair for each data stream successively aiming at maximizing the channel gain while suppressing the interference between different data streams. After all analog precoder/combiner pairs have been determined, we can obtain the effective baseband channel. Then, the digital precoder and combiner are computed based on the obtained effective baseband channel to further mitigate the interference and maximize the sum-rate. Simulation results demonstrate that our proposed algorithm exhibits prominent advantages in combating interference between different data streams and offer satisfactory performance improvement compared to the existing codebook-based hybrid beamforming schemes

Full duplex 60 GHz millimeter wave transmission over multi-mode fiber

Copyright @ 2010 IEEENew wireless subscribers are signing up at an increasing demand of more capacity for ultra-high data rate transfers at speeds more than 1 Gbps, while the radio spectrum is limited. Millimeter wave communication system offers a unique way to resolve these problems. In this paper, the performance of a full duplex transportation system is reported for 1.5 Km of multi-mode fiber length for a sample 10 Gbit/s pseudo random sequence data, with quadrature amplitude modulation mapping and orthogonal frequency division multiplexing modulation with 60 GHz RF and coherent 1550 nm optical carrier. The analysis and simulation results show that the system's quality of service depends on nonlinearity of electro optical modulator, dispersion and signal attenuation impairment of the multi-mode fiber cable