US 5,687,194 A · Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels

Abstract

A system for the wireless transmission of multiple information signals utilizing digital time division circuits between a base station and a plurality of subscriber stations. The subscriber stations may be fixed or movable. The number of time division circuits is determined by the transmission quality of the signals. The base station is interconnected with an external information network, which may be analog and/or digital. The information signals are selected from the group consisting of voice, data, facsimile, video, computer and instrumentation signals. The modulation level of the signals and the power applied to the system are adjusted in accordance with signal error detection in the system. The system is provided with spatial diversity by using a plurality of antennas selectively spaced from each other to provide relatively high signal reception despite signal fading. The base station operates over a plurality of RF channel pairs. Each channel pair operation is implemented by the combination of a transmit channel circuit for processing a given plural number of information signals received simultaneously over telephone company trunk lines for simultaneous transmission to different subscriber stations over a given RF channel, and a receive channel circuit for processing a plurality of signals received simultaneously over a given RF channel from different subscriber stations to provide information signals for transmission over the trunk lines.

Claims16

Dependent claims

A method for communication of at least one voice signal, comprising the steps of:

(1) assigning pathing for processing the information signal to be transmitted over an RF link to a receive unit;
(2) capturing in a predetermined manner the information signal being processed according to pathing assigned at substep (1) to produce signal samples representative of the information signal;
(3) compressing the signal samples by block encoding or waveform encoding such that the signal samples may be reconstructed at the receive unit to substantially provide the same information as the information signal provided before being processed according to the step (1) wherein the signal sample compression is performed at a given preselected rate;
(4) placing the compressed signal samples representative of the information signal in predetermined, discrete positions of each repeating segment of transmit signal channel;
and
(5) transmitting over an RF link to the receive unit the portion of each segment of the transmit signal channel containing the compressed signal samples representative of the information signal.

3 more elements

An apparatus for providing a plurality of voice signal channels on a plurality of forward direction carrier frequencies of a terrestrial RF telephone system, each of said forward direction carrier frequencies containing a plurality of slots, each of said forward direction carrier frequencies having an associated predetermined bandwidth which is designed to accommodate one analog voice signal channel therein, said apparatus comprising:

a base station comprising:
a plurality of circuit paths for processing a plurality of forward direction digitized voice signals from a public switched telephone network;
a plurality of compressors for respectively compressing each of said forward direction digitized voice signals by analyzing the speech content of said forward direction digitized voice signals and by using voice compression to form respective forward direction compressed voice signals, each compressed voice signal having a bit rate of less than 16 kb/s;
a processor for assigning each of the compressed voice signals onto a dynamically assigned frequency/slot;
a plurality of channel controllers, each for sequentially combining said respective forward direction compressed voice signals into a single transmit channel bit stream, with each of the respective forward direction compressed signals occupying a respective repetitive sequential time slot in the transmit channel bit stream;
a plurality of linear modulators for modulating said plurality of transmit channel bit streams, each of said modulators including a linear amplifier and using modulation to transmit at least 2 bits/symbol at a channel bit rate of between 32 kbps and 64 kbps;
and
a transmitter for RF transmitting said modulated signals on said forward direction frequency carriers to at least one mobile subscriber station, whereby said predetermined bandwidth is capable of carrying at least two bidirectional simultaneous conversations.

5 more elements

Dependencies are inferred from the claim text.

Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels

Life of this patent

Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels

Life of this patent

Abstract

Claims16