A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, bi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols. In the mobile-to-cell link, access and voice channels are defined. Information communicated on the mobile-to-cell link channels are, in general, encoded, interleaved, orthogonal signaling along with QPSK spreading.

System and method for generating signal waveforms in a CDMA cellular telephone system

A location reporting paging communication system comprising space satellites, ground stations and a remote receiving unit adapted to resolve a global position from signals transmitted from a communication transmitter. The subscriber in possession of the remote receiving unit updates the paging network with global positioning information. A caller paging a subscriber in possession of the remote receiving unit may request the global location of the remote receiving unit. The paging network could divulge or block such information from a caller depending on the requirements of the subscriber.

Location reporting satellite paging system with optional blocking of location reporting

A system and method for wireless communication between a plurality of subscriber units and a base station, the base station communicating information signals from an originating source to a destination subscriber unit over a channel at an assigned one of a plurality of frequencies using repetitive time frames, each said time frame comprising a sequence of time slots. The channel is defined as having the same one or more time slots from the sequence of time slots in one or more of the time frames. The base station includes a central processing unit capable of assigning a duration of time for the information signals being sent to the destination subscriber unit. The duration equals the duration of one or more time slots in the same frame. The central processing unit maintains a memory of which time slots of each time frame have been assigned and provides the time slot assignment, and therefore channel assignment, by consulting said memory. The system includes a multiplexer for multiplexing the information signals onto the assigned channel; and a transmitter for transmitting the information signals to the destination subscriber unit using the assigned channel.

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

In fabricating a thin film transistor, an active layer comprising a silicon semiconductor is formed on a substrate having an insulating surface Hydrogen is introduced into The active layer A thin film comprising SiO x N y is formed to cover the active layer and then a gate insulating film comprising a silicon oxide film formed on the thin film comprising SiO x N y  Also, a thin film comprising SiO x N y is formed under the active layer The active layer includes a metal element at a concentration of 1×10 15 to 1×10 19 cm −3 and hydrogen at a concentration of 2×10 19 to 5×10 21 cm −3 

Semiconductor device and method for forming the same

An apparatus and a method for routing data in a radio data communication system having one or more host computers, one or more intermediate base stations, and one or more RF terminals organizes the intermediate base stations into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Communication between the host computer and the RF terminals is achieved by using the network of intermediate base stations to transmit the data.

Radio frequency local area network

A communication system of the type wherein a central station assigns a limited number of information channels to a requesting one of a plurality of remote stations is disclosed. The requesting station sends its identification signal along with the request signal to the central station on a signal channel. The central station classifies the requesting station in either a priority or a non-priority queue. The priority queue corresponds to those stations which are continuing an on-going interchange, whereas the nonpriority queue contains those stations which wish to initiate an interchange. Stations are prioritized in the queues on a first-in/first-out basis. The central station constantly monitors the information channels and, as channels become available, assigns the channels first to stations in the priority queue, then to nonpriority queue stations. A channel becomes "available" when the central station detects a pause, such as a momentary release of a push to talk microphone switch, in transmission of that channel. By this transmission trunking method, the system makes optimum use of the limited number of available channels. Additional central station processing provides an acknowledgement signal, which indicates that the request was received and a channel will be assigned as soon as one becomes available. Also, the identification of a requesting station is compared with an associate memory. The memory provides the identifications of all stations to whom the requesting station would transmit. Once a channel is available, it is assigned to the requesting station and to its associated stations, whereby the associated stations are notified of, and prepared for, the impending transmission.

Transmission trunk multichannel dispatch system with priority queuing

The apparatus first measures the peak power of a multichannel signal, or representation thereof. The peak power is compared with one or more peak power threshold values. If the measured peak power exceeds a threshold value, the multichannel signal is attenuated prior to being processed by the linear power amplifier.

Apparatus and method for attenuating a multicarrier input signal of a linear device

A time division multiplexed (TDM) communication system, which apportions radio frequency communication channels into at least two time slots Voice signals for transmission on this system are analyzed and vo-coded into a digital signal that is transmitted during one or more of the time slots Received messages are recovered from at least one of these time slots and the voice message synthesized from the vo-coded signal In this manner multiple voice messages may be transceived in a time division multiplexed manner on a single narrowband communication channel

Tdm communication system for efficient spectrum utilization.

An adaptive audio filter system is disclosed which comprises a filter means capable of producing a plurality of frequency response characteristics. A control signal generating means provides a control signal to the filter means to enable a particular frequency response. The control signal is based upon the signal to noise ratio.

Adaptive signal strength and/or ambient noise driven audio shaping system

A method for interrupting a radio transmission in a quasi-duplex radio-frequency communication system. The method of the present invention includes the step of transmitting a signal (22), with periodically-occuring holes (24) therein, by a first communicatioin unit (10) to at least a second communication unit (12). The transmitted signal (12) includes an audio information portion (16) and information packets (23). Each information packet (23) specifies the time of occurence of the next hole (24). The second communication unit (12) initiates an interruption of the transmission made by the first communication unit (10) by transmitting an interrupt request signal (31) to the first communication unit (10) at a time specified by an information packet (23) received by the second communication unit (12). When the first communication unit (10) receives the interrupt request signal (31), it processes the interrupt request signal (23) to determine whether it complies with predetermined criteria. If the first communication unit determines that the interrupt request signal complies with the predetermined criteria, it transmits an acknowledgement signal allowing the second communication unit (12) to interrupt the transmission so that the second communication unit (12) may begin transmitting information to be received by at least the first communication unit (10).

Charles N. Lynk

Papers

Transmission trunk multichannel dispatch system with priority queuing

Apparatus and method for attenuating a multicarrier input signal of a linear device

Tdm communication system for efficient spectrum utilization.

Adaptive signal strength and/or ambient noise driven audio shaping system

Quasi-duplex radio system using bi-directional hole extension