Invention Grant
- Patent Title: Code division multiple access (CDMA) communication system
-
Application No.: US401628Application Date: 1999-09-22
-
Publication No.: US6157619APublication Date: 2000-12-05
- Inventor: Fatih Ozluturk , Alexander Jacques , Gary Lomp , John Kowalski
- Applicant: Fatih Ozluturk , Alexander Jacques , Gary Lomp , John Kowalski
- Applicant Address: DE Wilmington
- Assignee: InterDigital Technology Corporation
- Current Assignee: InterDigital Technology Corporation
- Current Assignee Address: DE Wilmington
- Main IPC: H04B1/707
- IPC: H04B1/707 ; H04B1/7075 ; H04B1/708 ; H04B1/7085 ; H04B1/7093 ; H04B1/7103 ; H04B1/7115 ; H04B1/712 ; H04B1/7183 ; H04B7/005 ; H04B7/26 ; H04J13/00 ; H04J13/10 ; H04L1/00 ; H04L25/02 ; H04L27/00 ; H04L27/20 ; H04L27/233 ; H04W52/00 ; H04W52/02 ; H04W52/04 ; H04W52/08 ; H04W52/36 ; H04W52/50 ; H04W88/02 ; H04W88/18
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 is 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.
Public/Granted literature
- US5454769A Wrist and forearm exercise apparatus with improved resistance adjustment device Public/Granted day:1995-10-03
Information query