Interdigital Technology Corporation

Alexander Marra

Fatih M Ozluturk

John Michael Kowalski

Gary R Lomp

Alexander M Jacques

Michael J Luddy

Robert T Regis

Avi Silverberg

Michael Luddy

Robert E Regis

A method and system for rapidly acquiring a spreading code, used in a code division multiple access (CDMA) system. A first long code and a second long code, with each long code having a length of N chips, are generated. The first long code is different from the second long code. The first long code and the second long code are transmitted at a first phase angle and at a second phase angle, respectively, on a carrier signal, over a communications channel using radio waves. The first long code and the second long code may be transmitted at an in-phase (I) angle and at a quadrature-phase (Q) angle, respectively, on the carrier signal. From the communications channel, an I-phase acquisition circuit and a Q-phase acquisition circuit may acquire, in parallel, the first long code and the second long code from the I-phase angle and the Q-phase angle, respectively, of the carrier signal by searching, in parallel, N/2 chips, the first long code and the second long code.

Rapid acquisition spreading codes for spread-spectrum communications

A spread spectrum system having an assignor, a spread-spectrum processor and a transmitter. The assignor assigns each arriving information signal to a message-code signal. Each message-code signal is different then other message-code signals. The spread-spectrum processor generates a pilot code signal and processes the information signals with the message-code signals to generate spread-spectrum process-message signals synchronized to the pilot-code signal. A transmitter combines the spread-spectrum process-message signals and the pilot-code signal to generate a CDM signal. The transmitter modulates the CDM signal with a carrier signal for transmission over the communications channel.

Spread spectrum system assigning information signals to message-code signals

A spread-spectrum system having an assignor, a spread-spectrum processor, a call processor, and an information-channel-mode modifier. The assignor assigns each information signal arriving at the spread-spectrum system to a message-code signal. Each of the message-code signals supports a pre-determined information-channel rate. Several information signals have different channel rates, and each information signal is assigned according to the required channel rate. The spread-spectrum processor generates a pilot-code signal, and spread-spectrum processes the information signals with the message-code signals to generate a plurality of spread-spectrum processed-message signals, respectively. The message-code signals are synchronized to the pilot-code signal. The call processor provides a call-type signal corresponding to the information signal rate for the several information signals having several different channel rates. In response to the call-type signal, the information-channel-mode modifier changes a combination of the information signals and the message-code signals to support the several different channel rates for the several information signals having several different channel rates.

Spread-spectrum system for assigning information signals having different data rates

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.

Bearer channel modification system for a code division multiple access (CDMA) communication system

Capacity management method for a code division multiple access (CDM) communication system

Code division multiple access (CDMA) communication system

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New York, NY, United States of America

Alexander Marra