Abstract: In the present invention a wireless communication system is disclosed. A base unit communicates with a remote unit. The system comprises means for transmitting, using CDMA, between the base unit and the remote unit, in one of a plurality of frequencies channels selected. In one period of time, the base unit transmits and in another period of time, different from the one period, the remote unit transmits. Further, the system comprises means for changing the one frequency channel selected to another frequency channel, different from the one frequency channel, in response to interference in the one frequency channel. Thus, communication between the base unit and the remote unit is then affected over the another frequency channel.

Abstract: In a wireless communication system between a base unit and a remote unit, the base unit transmits periodically a sync signal in a first selected time period in a selected frequency channel. The remote unit scans the frequency channels to detect the sync signal. The remote unit transmits a response signal in the selected frequency channel. The response signal is transmitted in a second selected time period different from the first selected time period. In addition, the remote unit transmits a first control signal encoded by a first code in the selected frequency channel in a third selected time period, different from the first and second selected time periods, containing a set of functional capabilities of the remote unit. The base unit receives and decodes the first control signal to derive the set of functional capabilities of the remote unit and compares it to its own set of functional capabilities to determine a common set of functional capabilities.

Abstract: In the present invention a wireless communication system is disclosed. A base unit communicates with a remote unit. The system comprises means for transmitting, using CDMA, between the base unit and the remote unit, in one of a plurality of frequencies channels selected. In one period of time, the base unit transmits and in another period of time, different from the one period, the remote unit transmits. Further, the system comprises means for changing the one frequency channel selected to another frequency channel, different from the one frequency channel, in response to interference in the one frequency channel. Thus, communication between the base unit and the remote unit is then affected over the another frequency channel.

Abstract: An adaptive hybrid circuit for use in a digital telephone switching system is disclosed. The hybrid circuit is adaptive in that it provides cancellation of a far end talker power component in an output signal having both far end talker and near end talker power components. The circuit includes first and second transfer filters for matching loaded and non-loaded subscriber loops, respectively, in the telephone system. The circuit generates a filtered signal representing the difference between loaded and non-loaded subscriber impedances in the telephone system and generates an adaptive control signal responsive to the filtered signal and the output signal such that the far end talker power component is cancelled.

Abstract: An echo cancellation circuit is disclosed for use with full-duplex data transmission systems. The echo canceller can operate in spite of time invariant non-linearities in the echo channel or in the implementation of the echo canceller itself (such as in D/A converters). The echo canceller receives an echo signal having linear and non-linear components and includes N linear tap weights for cancelling the non-linear components of that echo signal where M is greater than N but less than 2.sup.N.

Abstract: A frequency detector and method for use in timing and carrier recovery applications. In a timing recovery application, the circuit includes means for generating a variable frequency periodic clock signal corresponding to an input data signal, means for determining whether successive data transitions of the data signal occur during first and second predetermined portions of successive cycles of the clock signal and means for changing the frequency of the clock signal when successive data transitions occur during different ones of the predetermined portions.

Abstract: A reference source of digital pulses of a first frequency f.sub.1 is coupled to the input of a frequency synthesizer which is capable of providing a second frequency f.sub.2 output signal. The second frequency is related to the first frequency by a predetermined, rational fraction (e.g., as f.sub.2 = (M/N)f.sub.1). The synthesizer includes a phase control unit comprising an adder by way of which a first number N is added each sample period to a remainder, the sum output of the adder being operated upon modulo a second number M, e.g., by dividing by M and discarding a resultant quotient to obtain a remainder. The remainder, having a value between zero and M-1, is compared to a prefixed signal, illustratively the largest integer in M/2. If the remainder is less than the prefixed signal, a first logic state control signal is provided to a control system; else a second logic state signal is so provided.