Synchro Controller of Radar on FPGA

This paper mainly represents the realization of synchro controller based on the programmable logic devices FPGA by request of HF ground wave radar synchro controller under the instance of making the best of the virtues of FPGA. This design introduces the data communication between PC and synchro controller by PC Bus, which can carry the synchronous signals parameters to RAM of synchro controller, then according to the theory that the result of comparing counter value with signals parameters is the needed wave, we produce all waves HF ground wave radar needs, moreover all waves are produced time-sharing in order to save resources.

High-speed phosphorescent white LED visible light communications without utilizing a blue filter

We experimentally demonstrate a high-speed phosphorescent white light emitting diode （LED） visible light communication （VLC） system without utilizing an optical blue filter. Here, the white light response is equalized by using the proposed analog equalizers. The 3 dB bandwidth of the VLC link could be extended from 3 to 132 MHz, which allows 330 Mbit/s non-return-to-zero on-off keying （NRZ-OOK） data transmission with a bit error ratio （BER） of 7,2 × 10^-10 and 672 Mbit/s 64-quadrature amplitude modulation （64-QAM） data transmission with a BER of 3.2 × 10^-3. These resultant BERs are less than the forward error correction （FEC） limit of 3.8× 10^-3. The VLC link distance is 1 m using a single 1 W LED. The transmitter and receiver modules are integrated to a compact size. Furthermore, the relationships between the signal performance and illumination level or optical power are investigated and analyzed.

Communication Analysis and Granularity Assessment for a Transputer-Based System

This paper exposes the concurrent characteristic in the communication between processors in a transputer based system, and proposes an approximate formula for assessing the granularity of distributing the parallel processes among processors. The really measured results for a pipeline sorting program running on the T-rack confirm these deduced results.

200 Mb/s visible optical wireless transmission based on NRZ–OOK modulation of phosphorescent white LED and a pre-emphasis circuit

We present a high-speed visible light communication （VLC） link that uses a commercially available phos- phorescent white light-emitting diode （LED）. Such devices have few megahertz bandwidth due to the slow response of phosphorescent component, which severely limit the transmission data rate of VLC system. We propose a simple pre-emphasis circuit. With blue-filtering and the pre-emphasis circuit, the bandwidth of VLC system can be enhanced from 3 to 77.6 MHz, which allows non-return-to-zero on-off-keying （NRZ- OOK） data transmission up to 200 Mb/s with the bit error ratio of 5.3 × 10-7 which is below 10-6. The VLC link operates at the room illumination level of -1000 lx at 1.1 m range using a single 1 W white LED.

Combination of light-emitting diode positioning identification and time-division multiplexing scheme for indoor location-based service

A combination of light-emitting diode（LED） identification and a time-division multiplexing scheme is proposed in this Letter for indoor location-based service. With the scheme, the arrangement of white LED lamps and the structure of a data frame are designed to realize high-accuracy indoor positioning and location-based payload data transmission simultaneously. The results of the experiment demonstrate that the indoor positioning accuracy is 10 cm and 2 Mb/s data transmission with high signal quality is realized.

A new family of two-dimensional triple-codeweight asymmetric optical orthogonal code for OCDMA networks

A new generation algorithm of two-dimensional triple-codeweight asymmetric optical orthogonal codes for optical code division multiple access （OCDMA） networks is proposed. The code cardinality is obtained and the error-probability performance for corresponding OCDMA system is analyzed. The codes with two constraints （i.e., auto- and cross-correlation properties） being unequal are taken into account. On the premise of fixed system resources, the code of the error-probability performance, it is shown cardinality can be significantly improved. By analysis that the codes with different parameters have different performances. Therefore, this type of codes can be applied to support diverse quality of service （QoS） and satisfy the quality requirement of different multimedia or distinct users, and simultaneously make the better use of bandwidth resources in oDtical networks.

Optimal Partitioning and Granularity of Uniform Task Graphs

Task partitioning is an important technique in parallel processing.In this paper,we investigate the optimal partitioning strategies and granularities of tasks with communications based on several models of parallel computer systems.Different from the usual approach,we study the optimal partitioning strate- gies and granularities from the viewpoint of minimizing T as well as minimizing NT^2,where N is the number of processors used and T is the program execution time using N processors.Our results show that the optimal partitioning strategies for all cases discussed in this paper are the same——either to as- sign all tasks to one processor or to distribute them among the processors as equally as possible de- pending only on the functions of ratio of running time to communication time R/C.