Performance Evaluation for Medium Voltage MIMO-OFDM Power Line Communication System

Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical network.Most of research works have been done in low voltage(LV)scenario due to the fast development of in-home PLC.The aim of this paper is to evaluate the link-level performance of a medium voltage(MV)MIMO-OFDM communication system based on transmission link under underground power line channel.The MIMO channel is modeled as a modified multipath model in the presence of impulsive noise and background noise.We first perform a measurement on the practical MV MIMO channel parameters for a section of buried cable of 1 km long in Ganzhou city,Jiangxi province,China.Based on the measured channel,we design the frame structure based on an IEEE standard for broadband over power line networks[1]to support MV MIMO-OFDM transmission.According to designed frame structure,we design an encoder and a decoder for a dual binary tail-biting turbo code and optimize some key decoder parameters for low bit error rate performance.Finally,the link-level performance for both spatial multiplexing and spatial diversity are evaluated.Numeral results show that MV MIMO-OFDM is a promising approach to provide both high data rate and link reliability for PLC.

A FAST BIT-LOADING ALGORITHM FOR HIGH SPEED POWER LINE COMMUNICATIONS

Adaptive bit-loading is a key technology in high speed power line communications with the Orthogonal Frequency Division Multiplexing (OFDM) modulation technology. According to the real situation of the transmitting power spectrum limited in high speed power line communications, this paper explored the adaptive bit loading algorithm to maximize transmission bit number when transmitting power spectral density and bit error rate are not exceed upper limit. With the characteristics of the power line channel, first of all, it obtains the optimal bit loading algorithm, and then provides the improved algorithm to reduce the computational complexity. Based on the analysis and simulation, it offers a non-iterative bit allocation algorithm, and finally the simulation shows that this new algorithm can greatly reduce the computational complexity, and the actual bit allocation results close to optimal.

Particle filtering based channel estimation in OFDM power line communication

Particle filtering （PF） algorithm has the powerful potential for coping with difficult non-linear and non-Gaussian problems. Aiming at non-linear, non-Gaussian and time-varying characteristics of power line channel, a time-varying channel estimation scheme combined PF algorithm with decision feedback method is proposed. In the proposed scheme, firstly the indoor power line channel is measured using the pseudo-noise （PN） correlation method, and a first-order dynamic autoregressive （AR） model is set up to describe the measured channel, then, the channel states are estimated dynamically from the received signals by exploiting the proposed scheme. Meanwhile, due to the complex noise distribution of power line channel, the performance of channel estimation based on the proposed scheme under the Middleton class A impulsive noise environment is analyzed. Comparisons are made with the channel estimation scheme respectively based on least square （LS）, Kalman filtering （KF） and the proposed algorithm. Simulation indicates that PF algorithm dealing with this power line channel estimation difficult non-linear and non-Gaussian problems performance is superior to those of LS and KF respectively, so the proposed scheme achieves higher estimation accuracy. Therefore, it is confirmed that PF algorithm has its own unique advantage for power line channel estimation.

An analog front end with a 12-bit 3.2-MS/s SAR ADC for a power line communication system

This paper presents an analog front end for a power line communication system, including a 12-bit 3.2-MS/s energy-efficient successive approximation register analog-to-digital converter, a positive feedback programmable gain amplifier, a 9.8 ppm/℃ bandgap reference and on-chip low-output voltage regulators. A two segment capacitive array structure （6 MSB 5 LSB） composed by split capacitors is designed for the SAR core to save area cost and release reference voltage accuracy requirements. Implemented in the GSMC 0.13 #m 1.5 V/12 V dual-gate 4P6M e-flash process, the analog front end occupies an area of 0.457 mm2 and consumes power of 18.8 mW, in which 1.1 mW cost by the SAR ADC. Measured at 500 kHz input, the spurious-free dynamic range and signal-to-noise plus distortion ratio of the ADC are 71.57 dB and 60.60 dB respectively, achieving a figure of merit of 350 U/conversion-step.

Polar codes based OFDM-PLC systems in the presence of impulsive noise

Power line communication(PLC)has the potential to become the preferred technique for providing broadband communication to homes and offices with advantage of eliminating the need for new wiring infrastructure and reducing the cost.But it suffers from the impulsive noise because it introduces significant time variance into the power line channel.In this paper,a polar codes based orthogonal frequency division multiplexing(OFDM)PLC system is proposed to deal with the impulsive noise and thereby improve the transmission performance.Firstly,the impulsive noise is modelled with a multi-damped sine function by analyzing the time behavior of impulse events.Then the polar codes are used to combat the impulsive noise of PLC channel,and a low complexity bit-flipping decoding method based on CRC-aided successive cancellation list(CA-SCL)decoding algorithm is proposed.Simulations evaluate the proposed decoding algorithm and the results validate the suggested polar codes based OFDM-PLC scheme which can improve the BER performance of PLC with impulsive interference.

Analysis of electromagnetic field emitted from home plug power line used for indoor high-speed broadband communication

High-speed broadband power line communication(BPL)is a novel and practicable technique for NetatHome or home area local area networking(LAN).Because of the characteristics of BPL,the electromagnetic wave emitted from the BPL transmission media will influence the indoor electromagnetic environment,which would also affect the performance of other wireless communications.Based on the analysis of the communication channel characteristic,network impedance and attenuation characteristic of the BPL,this paper proposes a novel model for calculating the BPL radiation and the computer simulation model,which are proved by the coherence of the simulation and the test data.The interferences from the high-speed BPL to indoor wireless communications are analyzed to stipulate the standards of high-speed BPL in the future.

Exploiting the Cellular Infrastructure for Data Transmission in Smart Metering Systems

To implement the access and backhaul networks for Smart Metering (SM) systems various technologies are combined with the existing communications infrastructure. This paper deals with data transmission in SM systems, focusing on how the existing cellular networks infrastructure is employed to implement SM access communication networks. The analysis aims at analyzing the role of the cellular communications infrastructure taking into account the spatial distribution and installation points of the smart meters, the urban and topological characteristics of the SM deployment areas and the common practice so far followed by the utilities. It is demonstrated that cellular communications, either exclusively or combined with power line communications, enable immediate and scalable deployment of SM access communication networks at low installation cost, thus constituting the basic option for the implementation of smart metering.

Distributed and Decentralized Control Architectures for Converter-Interfaced Microgrids

This paper gives a summary on recently available technologies for decentralized and distributed control of microgrids.They can be classified into two general categories:1)power line communication based architectures and 2)multi-agent based architectures.The essential control methods and information sharing algorithms applied in these architectures are reviewed and examined in a hierarchical manner,in order to point out benefits they will bring to future microgrid applications.The paper is concluded with a summary on existing methods and a discussion on future development trends.