Invention Application
- Patent Title: CODE DIVISION MULTIPLE ACCESS (CDMA) COMMUNICATION SYSTEM
- Patent Title (中): 代码段多路访问(CDMA)通信系统
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Application No.: PCT/US9611063Application Date: 1996-06-27
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Publication No.: WO9702714A3Publication Date: 1997-02-13
- Inventor: LOMP GARY , OZLUTURK FATIH , KOWALSKI JOHN , REGIS ROBERT , LUDDY MICHAEL , MARRA ALEXANDER , JACQUES ALEXANDER
- Applicant: INTERDIGITAL TECH CORP
- Assignee: INTERDIGITAL TECH CORP
- Current Assignee: INTERDIGITAL TECH CORP
- Priority: US77595 1995-06-30
- Main IPC: H03K3/84
- IPC: H03K3/84 ; G06F13/374 ; H03H17/02 ; H03H17/06 ; H04B1/707 ; H04B1/7075 ; H04B1/7077 ; H04B1/708 ; H04B1/7085 ; H04B1/709 ; H04B1/7093 ; H04B1/711 ; H04B1/7115 ; H04B1/712 ; H04B7/005 ; H04B7/216 ; H04B7/26 ; H04B15/00 ; H04B17/00 ; H04J11/00 ; H04J13/00 ; H04J13/10 ; H04J13/12 ; H04J13/16 ; H04K1/00 ; H04L1/00 ; H04L5/14 ; H04L7/00 ; H04L7/033 ; H04L25/02 ; H04L27/00 ; H04L27/20 ; H04L27/233 ; H04L27/30 ; H04N1/333 ; H04W52/04 ; H04W52/14 ; H04W52/24 ; H04Q7/30
Abstract:
A multiple access, spread-spectrum communication system processes a plurality of information signals received by a Radio Carrier Station (RCS) over telecommunication lines for simultaneous transmission over a radio frequency (RF) channel as a code-division-multiplexed (CDM) signal to a group of Subscriber Units (SUs). The RCS receives a call request signal that corresponds to a telecommunication line information signal, and a user identification signal that identifies a user to receive the call. The RCS includes a plurality of Code Division Multiple Access (CDMA) modems, one of which provides a global pilot code signal. The modems provide message code signals synchronized to the global pilot signal. Each modem combines an information signal with a message code signal to provide a CDM processed signal. The RCS includes a system channel controller coupled to receive a remote call. An RF transmitter is connected to all of the modems to combine the CDM processed signals with the global pilot code signal to generate a CDM signal. The RF transmitter also modulates a carrier signal with the CDM signal and transmits the modulated carrier signal through an RF communication channel to the SUs. Each SU includes a CDMA modem which is also synchronized to the global pilot signal. The CDMA modem despreads the CDM signal and provides a despread information signal to the user. The system includes a closed loop power control system for maintaining a minimum system transmit power level for the RCS and the SUs, and system capacity management for maintaining a maximum number of active SUs for improved system performance.
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