Abstract: A transmission system (10). The transmission system communicates data to a number of subscribers (14a, 14b). The transmission system includes a transceiver (12) that has a number of highly directional antennas (28). A number of digital repeaters (16a, 16b, 16c) are disposed in a geographic region serviced by the transceiver. The repeaters include a sectorized antenna that communicates with subscribers in a number of sectors of the geographic region of the repeater. The repeater also includes an upstream demodulator/modulator circuit (19). The upstream demodulator/modulator circuit demodulates data from signals from subscribers that were modulated with a first modulation technique, and generates a re-modulated signal with the data using a second modulation technique.

Abstract: A method and apparatus for sectorizing coverage of a cellular communications area includes providing a remote unit having microcell antenna units. Each microcell antenna unit is configured to cover a particular sector. The remote unit is connected to a sectorized base station unit which is connected to a mobile telecommunications switching office. Separate digitized streams representative of telephone signals received from the mobile telecommunications switching office are generated corresponding to the microcell antenna units and the separate digitized streams are multiplexed and transmitted to the remote unit. The remote unit demultiplexes the multiplexed digitized streams into the separate digitized streams corresponding to the microcell antenna units and the separate digitized streams are converted to RF signals for coverage of a particular sector by the corresponding microcell antenna unit.

Abstract: A method of communicating a plurality of two-way inbound/outbound cellular telephone transmissions between a base station and a physically remote cell using a set of channels. At the base station, a plurality of outbound telephone transmissions, received from a network, are analog modulated onto respective ones of RF analog outbound channel carriers. The modulated analog channel carriers are combined to form a single RF analog outbound signal representing all of the outbound telephone transmissions in the set of channels. The analog outbound combined signal is subsequently digitized into a single stream of outbound digital samples and transmitted to the remote cell. At the remote cell, the stream of digital samples is converted back to the RF analog outbound combined signal and broadcasted directly to mobile units in the cell. Further, the remote cell receives a plurality of simultaneous inbound telephone transmissions from the mobile units as an RF analog inbound combined signal.

Abstract: A microcellular communications network has multiple base-station units all at a common location. Each unit has all-digital transmitters and receivers coupled by fiber optic cable to individual remote locations each having power amplifiers and diversity receivers which convert the RF signals directly between analog RF and digital signals in the RF band at the remote locations. The system includes filtering, framing, and multiplexing of multiple channels. The system also provides passive handoff and passive switching. The system may be deployed in two different stages.

Abstract: A microcellular communications network includes a plurality of base station units and corresponding antenna units. Each includes either conventional transmitters and receivers or all digital transmitter and receiver equipment, and interface circuitry to a mobile telecommunications switching office. The microcell traffic output is applied to a frame generator/multiplexer. The output of the frame generator/multiplexer is applied to a digitally modulated laser and conveyed by fiber to a remote antenna unit, which demultiplexes the microcell traffic signal, applies it to a digital-to-analog converter, and applies it to a power amplifier and a main antenna. The received signals are filtered, digitized, multiplexed together and transmitted over the optical fiber back to the base station. The strongest signal is selected for use. Deployment of an all digital microcellular communications system occurs in two stages.

Abstract: A microcellular communications network includes a plurality of base station units and corresponding antenna units. The base station units are housed in a common location. Each includes either conventional transmitters and receivers or all digital transmitter and receiver equipment, and interface circuitry to a mobile telecommunications switching office. The microcell traffic output is applied to a frame generator/multiplexer. The output of the frame generator/multiplexer is applied to a digitally modulated laser. The laser output is conveyed by fiber to a remote antenna unit, which demultiplexes the microcell traffic signal and applies it to a digital-to-analog converter. The output of the digital-to-analog converter is applied to a power amplifier, which in turn is connected to a main antenna. RF signals from the mobile units are received at both a main and a diversity antenna. The received signals are filtered, digitized, multiplexed together and transmitted over the optical fiber back to the base station.

Abstract: A passive handoff cellular communication system includes a cell divided into a plurality of zones. A base station is connected by transmission apparatus to a plurality of antenna units. The base station includes analog RF signal generation circuitry for generating a plurality of RF signals on different channels and a first switch responsive to a first control signal for switching and combining the RF signals to form a composite RF signal for each zone. Analog-to-digital conversion circuitry converts the composite signal for each zone to a digitized stream of samples and applies the samples to the transmission apparatus for transmission to each corresponding antenna unit.