Cisco Technology, Inc.

Samsung Electronics Co., Ltd.

Peter S Rha

Chol Su Kang

Sang Kyoon Hyun

Ki Hyun Joo

Joseph R Cleveland

John S Csapo

A wireless office communication system including a wireless internet base station (WIBS) encompassing a base station controller, a mobile switch controller and an ethernet interface module for coupling the WIBS to an existing internet protocol (IP) based network. A wireless office communication system can also be based on the conventional architecture comprising the BTS, BSC and MSC. The WIBS or BTS is attached to a number of antennas via different and identifiable delay elements for the purpose of determining the serving antennas of mobile communication units. A location determination logic enables the system to handle handoffs between a WIBS or BTS and the external public communication system in an optimum manner. Handling handoff requests in this manner prevents unnecessary ping-ponging of handoff and can also increase the percentage of successful handoff by frequency monitoring of the quality of the mobile communication units located in the handoff transition area, particularly to the public communication system.

Handoff control in an enterprise division multiple access wireless system

A wireless office communication system including a wireless internet base station (WIBS) encompassing a base station controller (BSC), a mobile switch controller (MSC), and an ethernet interface module for coupling the wireless internet base station (WIBS) to an existing internet protocol (IP) based network. A wireless office communication system can also be based on the conventional architecture comprising the base station transceiver subsystem BTS, BSC, and MSC. The WIBS or BTS is attached to a number of antennas via different and identifiable delay elements for the purpose of determining the serving antennas of mobile communication units. A location determination logic enables the system to handle handoffs between a WIBS or BTS and the external public communication system in an optimum manner. Handling handoff requests in this manner prevents unnecessary ping-ponging of hand off and can also increase the percentage of successful handoff by frequency monitoring of the quality of the mobile communication units located in the handoff transition area, particularly to the public communication system.

Method of handoff control in an enterprise code division multiple access wireless system

A telecommunication base station transceiver subsystem that can be easily configured to provide single or multi-carrier frequency service. Capacity is increased and diversity reception is maintained from a single to a dual frequency system without the need for additional antennas. The base station is divided into a main unit and a radio unit such that the radio unit is positioned proximate to the antennas and the main unit is remotely located from the radio unit. Furthermore, a single base station transceiver can provide service via multiple wireless protocols, such as CDMA, TDMA, GSM or Analog. The base station transceiver can also operate on various transmit/receive frequencies as well as variable transmit power settings.

Distributed architecture for a base station transceiver subsystem

A digital feedforward (FF) amplifier system is disclosed for use in an RF transmission system. The digital FF amplifier uses digital signal processing to generate error correction signals that reduce intermodulation distortion caused by saturation of the main power amplifier. The digital signals in the improved FF amplifier may be buffered, if necessary, thereby eliminating the need for delay lines. A main amplification branch includes a digital combiner for summing input digital signals, digital-to-analog converters, RF modulation circuitry and a main power amplifier. An error correction signal branch includes an error correction signal generator, digital-to-analog converters, and RF modulation circuitry. The RF outputs of the main amplification branch and the error correction signal branch are combined to produce an RF output signal with reduced distortion. Optionally, an amplifier characterization branch may be included comprising RF output feedback circuitry and an amplifier model. The amplifier model updates the error correction generator with time varying characteristic information about the main power amplifier.

Digital feedforward amplifier for use in an RF transmitter and method of operation

There is disclosed, for use in a wireless network, a single-loop feedforward amplification system. The single loop comprises a main amplification branch and a feedforward branch in parallel to the main amplification branch. The main amplification branch contains a delay line that receives and delays the initial low-power input signal, and a power amplifier that amplifies the delayed input signal to produce an amplified output signal. The feedforward branch also receives the input signal and generates an distortion correction signal to compensate for the distortion produced at the output of the power amplifier due to its non-linearity. The distortion correction signal and the distorted amplified output signal are then combined to create a corrected amplified output signal without distortion.

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Santa Clara, CA, United States of America

Peter S Rha