Abstract: A communications system includes a first and second communication unit coupled together via a radio communications link. In one embodiment, the communications system takes the form of a frequency hopped, spread spectrum digital cordless telephone, where the first unit is a base unit and the second unit is the remote unit. The first and second communication units are respectively set to transmit and receive communication over a first radio frequency during a first time frame, select a second radio frequency during the first time frame, and set to respectively receive and transmit communication over the second radio frequency during a second time frame.

Abstract: In one aspect of the present invention, a method and apparatus are provided. The method includes detecting a synchronization signal within a plurality of channels. The method includes selecting a subset of the plurality of channels, wherein the subset includes more than one channel. The method further includes determining if the synchronization signal exists on at least one of the subset of channels and initiating communications in response to determining that the synchronization signal exists on at least one of the subset of channels.

Abstract: In the broadcast band having a plurality of channels allocated therein, by using high-side injection and low-side injection as described herein, the noise introduced into the channel by the local oscillator signal can be minimized. The local oscillator signal in combination with the intermediate frequency determines the frequency of the channel signal being produced by the transmitter. The selected high-or low-side injection determines whether the bulk of the power is introduced into the combination frequency signal (i.e., the channel) above or below the local oscillator frequency, thereby moving the local oscillator frequency outside the broadcast band. The non-selected sideband is even further outside broadcast band.

Abstract: A free channel selector for selecting from a plurality of channels an optimal channel for establishing radio communication. The channels may be selected by a radio frequency (RF) module for outputting sampled signals carried on that channel. The selected signals are digitized and provided to a peak detector. The peak detector compares the strength of the signals from the various channels. A memory device, having an array of cells, is provided for storing values representative of the sampled signals of each of the plurality of channels, each of the stored values being stored in a cell having an address indicative of the channel on which the signal represented by the stored value is carried. A stored value corresponding to the lowest signal strength is selected as being the free channel. Communication will then occur over that channel.

Abstract: In one aspect of the present invention, a method and apparatus are provided for tracking a plurality of frequency-shift-key modulated signals in a communications device. The method includes determining a first threshold value for a first input signal of the plurality of signals, comparing the first input signal to the first threshold value and providing a first output signal. The method includes determining a second threshold value for a second input signal of the plurality of signals, and retaining at least a portion of the first threshold value while determining the second threshold value.

Abstract: A cordless telephone provides extended operating range and battery life. In one embodiment, a time division duplex communications protocol is used when the measured signal strength or the signal quality between the handset and a corresponding base unit does not satisfy a known criteria, such as a predetermined threshold. The telephone is also configured to operate using a frequency division duplex communications protocol when the signal strength or signal quality between the handset and the base unit satisfies the known criteria. Other aspects of the invention are directed to measuring the received signal strength of the communications channel after initial communications is established, and selecting the communications protocol that is most advantageous in light of the measured signal strength and/or signal conditions.

Abstract: Described herein is a system and method of disabling D bits in a CT2 MUX signaling channel. When the bit count equals the bit location of where the D bits are typically located in the signaling channel of a CT2 MUX, circuitry of the present invention disables a D bit enable signal from being processed. The D bit enable signal would typically allow a transmitter and receiver to, respectively, send a bit as a D bit, or process a received bit as a D bit. The suffix of the CT2 MUX, consisting of D bits, is unaffected by the present invention.

Abstract: A system for radio frequency communications between a first unit and a second unit. The communications are conducted over a first frequency and a second frequency. The first unit and the second unit each transmit and receive communications, including first, second, third and fourth information, in bursts over select time intervals, including a first time interval and a second time interval. The system includes communication between a plurality of wireless handset units and a base unit utilizing a FDD/TDD format.

Abstract: An apparatus for turning power to a device on and off is disclosed. The apparatus comprises a first signal input, a second signal input, a first charge output electrically connected with the first signal input, a transistor electrically connected with the second signal input, and a second charge output electrically connected with the transistor. The first charge output, when the first signal input and second signal input are powered on, electrically ramps up a first portion of the device. This ramp up of the first portion draws from current available to ramp up a second portion of the device. The second charge output is, thus, provided. The second charge output, when the first signal input and second signal input are powered on, electrically charges the transistor and the transistor electrically ramps up the second portion of the device concurrently with the ramp up of the first portion.

Abstract: A free channel selector for selecting from a plurality of channels an optimal channel for establishing radio communication. The channels may be selected by a radio frequency (RF) module for outputting sampled signals carried on that channel. The selected signals are digitized and provided to a peak detector. The peak detector compares the strength of the signals from the various channels. A memory device, having an array of cells, is provided for storing values representative of the sampled signals of each of the plurality of channels, each of the stored values being stored in a cell having an address indicative of the channel on which the signal represented by the stored value is carried. A stored value corresponding to the lowest signal strength is selected as being the free channel. Communication will then occur over that channel.

Abstract: A method of radio frequency communications between a first unit and a second unit. The method includes the steps of transmitting during a first time interval over a first frequency by the first unit, receiving during the first time interval over the first frequency by the second unit, transmitting during a second time interval over a second frequency by the second unit, receiving during the second time interval over the second frequency by the first unit. The method also includes the step of setting a select frequency shift between the first frequency and the second frequency. In one application of the method, the first unit is a cordless telephone hand set and the second unit is a cordless telephone base station. The method is particularly effective when the first unit and the second unit operate in TDD mode.

Abstract: A digital cordless telephone communicates with a telecommunications network over a wire link and receives first communications signals from and delivers second communications signals to the telecommunications network. The digital cordless telephone includes a cordless fixed part connected to the wire link for receiving the first communications signals from the telecommunications network and for sending the second communications signals to the telecommunications network over the wire link. The cordless fixed part also transmits the first communications signals, together with first control information generated by the cordless fixed part, including a channel identifier indicative of a desired radio frequency communication channel, and receives the second communications signals, together with second control information.

Abstract: An apparatus for furnishing instructions having a multi-stage pipeline processing unit for processing at least a "fetch instruction" phase, a "decode instruction" phase and an "execute instruction" phase, includes a memory; an address register having contents pointing to an instruction to be processed in said memory; an instruction register for receiving a loading of the instruction during an instruction loading phase; an arithmetic calculation unit for calculating addresses; an incrementing stage for incrementing the contents of said address register; and a multiplexer for selecting a calculated address or an incremented successor address. One embodiment also includes a first additional memory unit; a second additional memory unit; an address comparator; and a third additional memory unit. Another embodiment also includes a first additional memory unit; a second additional memory unit; an address comparator; and a third additional memory unit.