Lucent Technologies Inc.

At+t Corp.

Jack C Wen

Robert Evan Myer

Christopher F Zappala

John Stanley Rucki

Carmine J Pagano

Farid Firouzbakht

A wireless communication system or method capable of providing both a two-way telephone service and a two-way paging service on the same infrastructure. The system or method is capable of distinguishing whether a subscriber is a telephone or paging subscriber. If the subscriber is a two-way paging subscriber, the system or method allows the calling party to have the capability of conversing directly with the called party for a limited time or the options of leaving voice, numeric or alphanumeric messages for the called party to retrieve later.

Two-way telephone and two-way paging service on the same wireless infrastructure

A wireless base station has a transmitter and receiver. Transmission signals are applied to an antenna through a transmit bandpass filter that is tuned for a transmit band of frequencies. Received signals from the antenna are applied to the receiver through a receive bandpass filter that is tuned for a receive band of frequencies. An RF switching array consisting of four RF switches interconnects the output of the transmitter and the input of the receiver such that normal, loopback (self-test), and scanning modes can be performed. In the normal mode, the antenna is connected to the transmitter and receiver through the transmit and receive bandpass filters, respectively. The transmit and signal paths are effectively isolated from each other by three serially-connected open switches. In the loopback mode, the transmitter output is connected to the receiver input. In the scanning mode, the antenna is connected to the receiver through the transmit bandpass filter. The same set of interconnects provides for loopback and normal operation as well as the new scanning operation. The use of switches rather than couplers or couplers for the loopback function reduces noise and crosstalk between transmit and receive signal lines and lower losses in these lines.

Transceiver with RF loopback and downlink frequency scanning

Disclosed is a channelized multi-carrier signal processor capable of equalizing power levels of individual carriers of a multi-carrier signal to within a predetermined dynamic range. In one embodiment, the signal processor includes a power splitter for splitting a multi-carrier input signal into a plurality of electrical paths. In each electrical path there resides a signal modifier that is operable to isolate signal energy associated with a given carrier of the multi-carrier signal. Each signal modifier includes an automatic gain control (AGC) circuit to control the power level of the carrier isolated therein to within a predetermined power level window so that the isolated carriers of each signal modifier are equalized in power. A power combiner then combines the equalized carriers to produce a multi-carrier output signal, which can be applied to a limited dynamic range device such as an A/D converter. Preferably, the carriers are isolated with the use of a tunable frequency synthesizer and a down-converting mixer within each signal modifier. This arrangement provides flexibility as to the frequencies which can be used for the modulated carriers of the multi-carrier input signal.

Channelized apparatus for equalizing carrier powers of multicarrier

Some embodiments of the present invention are capable of reducing the dynamic range of multicarrier signals. In an exemplary embodiment, the multicarrier signal processor includes a controller configured to receive at least a portion of a multicarrier signal, the controller analyzing the signal to identify at least one carrier signal of the multicarrier signal to be modified. At least one signal modifier communicates with the controller, the signal modifier receiving at least a portion of a multicarrier signal. The signal modifier isolates a carrier signal to be modified as directed by the controller, and modifies the isolated carrier signal. A negative delay is imparted to the carrier signal. A signal combiner receives the modified carrier signal and combines it with an unmodified multicarrier signal. Preferably, the multicarrier signal processor is used to reduce the dynamic range of a multicarrier signal.

Method and apparatus for processing multicarrier signals

The present invention provides an improved cellular communications system which reduces the dynamic range of a received multicarrier signal. The cellular communications system includes at least one cell site. A base station cooperating with an antenna is positioned within the cell site and is configured to communicate with at least one wireless terminal. A receiver is positioned within the base station for receiving multicarrier signals. Within the receiver is positioned a dynamic range-reducing multicarrier signal processor which reduces the dynamic range of a received multicarrier signal.

Cellular communications system with multicarrier signal processing

Disclosed is an apparatus for digitizing an electromagnetic input signal having frequency components within at least first and second segregated frequency bands, particularly useful in a wireless communications system. The apparatus includes a filtering circuit arrangement for passing only frequency components of the input signal substantially within the first and second frequency bands, to provide a filtered signal having a spectrum with spectral components below a predetermined power level within a frequency gap between the first and second frequency bands. An analog to digital (A/D) converter samples the filtered signal at a sampling rate sufficient to provide a digitized output signal with a frequency spectrum corresponding to that of the filtered signal and also with a replica of spectral components of one of the frequency bands appearing within the frequency gap. Preferably, the sampling rate used is less than the Nyquist sampling rate for the composite frequency band extending from the lowest to highest frequencies of the two bands. This allows a single A/D converter to be employed to sample the filtered signal, even when a large frequency gap exists between the segregated bands. A single mixer stage can then be used in conjunction with the single A/D converter in a wireless communications receiver application.

Segregated spectrum RF downconverter for digitization systems

A wireless-based communications system is provided with a method and apparatus for automatic verification of the identity of a mobile phone user in order to eliminate cellular piracy. A first embodiment implements a memory-based verification and a second embodiment implements an algorithm-based verification to reduce memory space requirements. The call is allowed when verification passes and is disallowed when verification fails.

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Parsippany, NJ, United States of America

Jack C Wen