US 6,157,619 AGranted

Code division multiple access (CDMA) communication system

AssigneeInterDigital Technology Corporation

InventorsFatih Ozluturk, Alexander Jacques, Gary Lomp, John Kowalski

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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.

A multiple access, base station test apparatus for acquiring and providing a plurality of system parameters of a Code Division Multiple Access (CDMA) communication system, the base station test system receiving a forward telecom signal, and processing the forward telecom signal for transmission as a forward CDM signal to a subscriber unit (SU), the apparatus comprising:

receiving means for receiving the forward telecom signal, and converting the telecom signal into a forward information signal and a forward call request signal;
master modem processing means including
a) means for providing a global pilot code signal and at least one broadcast channel signal,
b) means for combining, responsive to the forward call request, the forward call request and a message pilot identifier with the at least one broadcast channel signal, wherein the at least one broadcast channel signal is synchronized to the global pilot code signal;
and
c) means for measuring and storing master modem system information,
slave modem processing means for providing the forward information signal as a modulated forward CDM message signal, the slave modem processing means including
a) means for measuring and for storing slave modem system information, and:
b) forward processing means for modulating the forward information signal with one of a plurality of forward message code signals, the one of the plurality of forward message code signals corresponding to the message pilot identifier, to provide the modulated forward CDM signal, wherein the plurality of forward message code signals are synchronized to the global pilot code signal;
and
system control means, coupled to the master modem processing means and the slave modem processing means, for retrieving the stored master modem system information and the stored slave modem system information, the system control means including means for processing, responsive to a request signal, the stored master modem system information and the stored slave modem system information into a data record signal having the plurality of system parameters.

8 more elements

Facts

Application

09/401,628Filed 22 Sep 1999 · division

Priority

27 Jun 1996

Granted

5 Dec 2000

Term ends

Not estimatedThe source records don’t support an estimate.

Classification59 codes

H04B 1/707
Spread spectrum techniques: using direct sequence modulation
H04B 1/7075
Synchronisation aspects: with code phase acquisition
H04B 1/70753
Using partial detection: partial phase search
H04B 1/70754
With code phase acquisition: setting of search window, i.e. range of code offsets to be searched

Abstract

Claims8