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.
WANG Ye-qiuLU Ying-huaZHANG Hong-xinHE Peng-feiZHANG Li-kun
The electromagnetic radiation will result in informa- tion 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.
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.
HE Peng-fei LUE Ying-hua ZHANG Hong-xin WANG Ye-qiu XU Yong
