User-Identification Position-Sensing Asynchronous CDMA Communication System Using Finite-Length PN-Sequences

在自组织网络或传感器网络中，期望一种识别信号发送者并同时感测发送者的位置的技术。本计画旨在发展一个使用有限长度PN序列的异步码分多址通讯与位置感测系统。本研究取得的主要成果如下。(1)实值有限长序列的研究针对该系统，开发了一种能带来高传输效率的序列集。为了满足用户选择性组网的需要，本文还研究了其他具有脉冲相关性的序列对，使其传输效率略有降低。(2)多路复用通信系统的开发由长度为65的实值序列分配的用于4个用户的通信系统已经被开发为从多速率数据发送二值调制信号，并且通过相关处理对数据进行解调，其中干扰、噪声和幅度失真被抑制。该系统具有频率利用率高，对幅度失真的容忍度比OFDM系统（如用于地面电视系统）更强。(3)位置感测系统已被开发为通过将从放置在三角形的顶点上的发射天线和三个欺骗天线之间的距离差导出的双曲线相交来计算位置。检测位置的精度取决于天线之间的距离和系统时钟的时间间隔。开发的系统用于检测拥有代码的人或物体并与每个人进行通信。未来的课题是研究和开发实用的改进。

In the ad hoc network or sensor network, a technique to identify a signal sender and simultaneously to sense the position of the sender is desired. This project aimed to develop an asynchronous CDMA communication and position-sensing system using finite-length PN sequences. The achievements of the research are as the followings.(1) Research on real-valued finite-length sequences For this system, a sequence set to bring high transmission efficiency has been developed. For user's selective formation of wireless network, other sequence pairs with impulsive correlation are investigated, to bring a little lower transmission efficiency.(2) Development of multiplexing communication system The communication system for 4 users allotted by real-valued sequences of length 65 has been developed to transmit two-valued modulated signal from multi-rate data and to demodulate the data with interference, noise and amplitude distortion suppressed through correlation processing. This system has high efficiency of frequency usage and the stronger tolerance with amplitude distortion than the OFDM system (as adopted to terrestrial TV system).(3) The position sensing system has been developed to calculate the position by intersecting the hyperbolas derived from distance differences between a transmitting antenna and three Deceiving antennas placed on the apex of a triangle. The accuracy of detected position depends on the distances between the antennas and on the time interval of system clock.The developed system for detecting the person or object possessing a code and communicating with each is a proposal. The future subject is the research and development of improvements for practical use.