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公开(公告)号：US4930139A
公开(公告)日：1990-05-29
申请号：US359206
申请日：1989-05-31
IPC分类号： H04B1/707 , H04B1/7093 , H04J13/00
CPC分类号： H04B1/7093 , H04B1/707 , H04J13/00
摘要： The spread spectrum digital communication system includes data input devices for generating digital information signals to be transmitted using radio signals. A chip stream generator converts the data bits into chip streams that are either complemented or not complemented via an exclusive-OR gate, depending on the data bits. A scrambler further randomizes the chip stream for transmission. The receiver includes a descrambler and a correlator or digital matched filter for detecting the data signal. A modified receiver includes a sampler for sampling the scrambled signal at a rate which is the multiple of the chip rate thereby eliminating any need for recovering the chip clock. Another modified version includes a receiver having means for generating multi-level signals indicating the quality of the probable detection.
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公开(公告)号：US5142534A
公开(公告)日：1992-08-25
申请号：US599673
申请日：1999-10-17
CPC分类号： H04W72/0446 , H04B7/2643 , H04L1/0057 , H04L1/0065 , H04L1/06 , H04B1/715
摘要： A digital voice-data communication system having a base network control unit coupled to a plurality of fixed transceivers for providing communications to a plurality of portable sets. The base network control unit includes control means for permitting communication between the portable sets within the system, or between the portable sets and a larger external telecommunications network. The system employs frequency hopping, time division multiplexing and demand assigned multiple accessing to permit economy of fixed resources via multiple voice channels for each fixed station transceiver and relatively simple portable sets which may be hand held.
摘要翻译： 一种数字语音数据通信系统，其具有耦合到多个固定收发器的基本网络控制单元，用于向多个便携式组提供通信。 基站网络控制单元包括用于允许系统内的便携式设备之间或便携式设备与更大的外部电信网络之间的通信的控制装置。 该系统采用跳频，时分多路复用和分配多次访问的需求，可以为每个固定站收发机和相对简单的便携式设备提供固定资源的经济性。
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