Ying-hua Lu

Design and implementation of high-speed real-time data acquisition system based on FPGA

Abstract The electromagnetic radiation will result in information leakage being recovered when computers work. This article presents a high-speed real-time data acquisition system based on peripheral component interconnect (PCI) bus and field programmable gate array (FPGA) for sampling electromagnetic radiation caused by video signal. The hardware design and controlling flow of each module are introduced in detail. The sampling rate can reach 64 Msps and system transfers speed can be up to 128 Mb/s by using time interleaving, which increases the overall sampling speed of a system by operating two data converters in parallel.

Implementation of compressive sensing in ECG and EEG signal processing

Abstract The purpose of this paper is to exploit compressive sensing (CS) method in dealing with electrocardiography (ECG) and electroencephalography (EEG) signals at a high compression ratio. In order to get sparse data of ECG and EEG signals before being compressed, a combined scheme was presented by using wavelet transform and iterative threshold method; then, compressive sensing is executed to make the data compressed. After doing compressive sensing, Bayesian compressive sensing (BCS) is used to reconstruct the original signals. The simulation results show that compressive sensing is an effective method to make data compressed for ECG and EEG signals with high compression ratio and good quality of reconstruction. Furthermore, it shows that the proposed scheme has good denoising effects.

SAW chirp Fourier transform for MB-OFDM UWB receiver

Abstract In the conventional multiband orthogonal frequency division multiplexing ultra wideband (MB-OFDM UWB) receiver, the fast Fourier transform (FFT) algorithm is realized by the expensive and power-consuming digital signal processor (DSP) chips. In this article, the lower power, lower cost, and lower complexity real-time analog surface acoustic wave (SAW) chirp Fourier transform devices were used to replace the DSP part. A MB-OFDM UWB receiver based on the M-C-M SAW chirp Fourier transform was presented, and the step of signal transformation from input signals was also depicted. The simulation results show that the proposed receiver provides similar bit error performance compared to the fully digital receiver when used in the channel environments proposed by the IEEE 802.15SG3a.

Eavesdropping the display image from conducted emission on network cable of a PC

Abstract The display image of a PC can be reconstructed by using the conducted emission on the PCs network cable. The relevant signals which be used to reconstruct the original image are coupling from the radiation of the switching of red, green, blue (RGB) signals in PC. These pertinent signals are partly contained in the frequency region higher than 30 MHz in the conducted emission. From these findings, the near-field coupling principle from PC to the network cable is analyzed firstly. And then, a multi-conductor transmission model for the RGB signals which transmit in the network cable is proposed. In addition, the maximum safe distance is estimated by using this model. In order to check the validity of the estimating distance, the eavesdropping experiment is carried out to reconstruct the original display image. The results demonstrate that the blurred display image can be retrieved at the place of 29.5 m.

Coexistence of broadband power line communication systems

Abstract Recent progress in home networks enhances the application of broadband power line communication (BPL) since it does not require any installation of new communication lines or outlets. However, high-density distribution of BPL devices may bring down the access quality. Besides, the electromagnetic field radiating from the power line may cause interference with other radio systems. Thus, the objective of this study is to investigate the impact of cumulative interference in BPL systems, especially focused on indoor environment. A 2-D model describing the BPL transmission activity is proposed. Based on transmission characteristics of the main networks, it takes into account the coexistence effect of the BPL devices. The maximum acceptable density of BPL devices and the radiation field are finally determined.

UWB multi-pulse position modulation for high data-rate wireless application

A new ultra-wide band (UWB) modulation scheme called L-ary ultra-wide band time hopping multi-pulse position modulation (UWB-TH-MPPM) is proposed for high data-rate wireless application, which can provide better communication performance. The constant weight code is introduced to construct the MPPM signal and the comparison between MPPM and single pulse position modulation (SPPM) is done in three aspects, namely, power efficiency, bandwidth efficiency, and probability of symbol error, respectively. The theoretical analysis and the numerical results show that when the constant weight code is appropriately chosen, MPPM can achieve lower probability of symbol error and higher power efficiency than SPPM at the cost of more bandwidth under the same condition. The proposed MPPM can be a good candidate in UWB system design.

Simulation analysis on co-site interference of vehicular digital communication system based on IM prediction method by BER

Abstract The co-site interference exists in kinds of communication systems, especially in digital communication systems, also is one of the biggest threats in electromagnetic compatibility (EMC) designation of the systems. Analyzing the co-site interference is an important process in achieving EMC performance of the system. Under the situation, the co-site interference simulation analysis of a vehicular digital communication system based on interference margin (IM) prediction method by bit error ratio (BER) was proposed in the paper. In the simulation analysis, some physical models of the vehicular communication system were established on SIMULINK environment, the upper limit of BER level for audio signals was defined as the IM, three different types of co-site interference was analyzed respectively, and the simulation results were obtained in the form of system interference bandwidth. From these results, the EMC performance evaluation of the vehicular communication system was predicted based on the IM prediction method. By comparing with the actual test results, the correctness of the simulation results was validated and the simulation analysis method can be used for reference by other communication systems was indicated.

The influence of different measurement antennas on the radiated emission measurement

The radiated emission(RE) measurement is the one of test items in the electromagnetic compatibility(EMC) test. The different standards specify the different measurement antennas for the radiated emission measurement in the frequency range of 200MHz to 1000MHz. In this paper, we investigate the influence of the different measurement antennas on the radiated emissions measurement. The measurement results show that the different measurement antennas will introduce the great measurement uncertainty in the radiated emissions measurement.

Direct computation of multiconductor transmission line capacitance and charge distribution

The per-unit-length capacitance parameter of multiconductor transmission line (MTL) is commonly extracted with indirect matrix transform method, which is complex and time-consuming. To solve the problem, an improved method to directly compute the MTL capacitance is proposed, which can be applied in the transmission line structure with arbitrary shaped cross-section and arbitrary separate distance. This method imports voltage conversions and matrix operations to simplify the complexity, improves computational efficiency by about 600% with results as accurate as previous method. The novel method presents a clear charge distribution map of MTL, whereas precious method will experience a tortuous process to get charge distribution.

Specification, Validation and Implementation of ATM UNI Signaling Protocols in SDL

We are involved in an industry project to build an ATM network access system. During the first phase of our project, we used conventional way of writing C code manually. We were able to implement ATM access signaling protocols. However, the code is not reliable, a lot of efforts were spent on testing the codes and fixing the bugs during the integration phase. During the second phase, we switched to formal design technique SDL (Specification and Description Language)[ 7 ] and we used the ObjectGEODE [ 5 ] CASE tool. We formally specified the protocols in SDL, we validated their logical correctness and we automatically generated the C code, and targeted the code on hardware. We reached a significant improvement on software quality, reliability and time to market. In this paper, we present our approach in the use of the formal SDL methodology in real life protocol developing which have general industrial application value, and our experience to implement the ATM UNI signaling protocols. Several key aspects including interpreting system configurations, modeling UNI signaling protocols in SDL, validating, implementing and testing the protocols are addressed respectively.