Abstract: A method detects an absence of a transmitted frame in a wireless communications system that operates with a discontinuous transmission (DTX) protocol between a transmitter and a receiver. The method includes decoding a received signal over a frame period to determine a cumulative metric; normalizing the cumulative metric and comparing the normalized cumulative metric to a threshold for determining whether the frame was a transmitted frame or a non-transmitted frame. The determined cumulative metric may be a maximum cumulative metric or a zero state cumulative metric. The wireless communications system may be a CDMA system, the receiver may be contained within a mobile station, and the determination of whether the frame was a transmitted frame or a non-transmitted frame can be employed, as one non-limiting example, during execution of a power control algorithm.

Abstract: Apparatus, and an associated method, by which to facilitate regulation of power levels of a communication signal generated during operation of a communication system. Closed-loop power control is effectuated by selectively generating a power control command such as a power up or power down command responsive to calculated time rates of change of a calculated difference value. By generating a power command responsive to calculations of time rates of change, earlier decisions are made of the power control commands than conventionally permitted in conventional closed-loop power control schemes.

Abstract: A method, system, and computer program product for controlling amplification of an input transmit signal in a transmitter in order to operate a digital-to-analog converter such that its clipping point corresponds to a desired cumulative distribution level. The input transmit signal is coupled to a digital-to-analog converter and includes a plurality of independent spread spectrum channels. The spread spectrum channels have associated individual channel gains. The invention includes an approximating the total variance of the input transmit signal and determining an amplification gain corresponding to the desired cumulative distribution level using an amplification function dependent on the total variance of the input transmit signal.

Abstract: A method, system, and computer program product for controlling amplification of an input transmit signal in a transmitter in order to operate a digital-to-analog converter such that its clipping point corresponds to a desired cumulative distribution level. The input transmit signal is coupled to a digital-to-analog converter and includes a plurality of independent spread spectrum channels. The spread spectrum channels have associated individual channel gains. The invention includes an approximating the total variance of the input transmit signal and determining an amplification gain corresponding to the desired cumulative distribution level using an amplification function dependent on the total variance of the input transmit signal.

Abstract: Apparatus, and an associated method, for a communication station, such as a mobile station operable pursuant to an IS-95/IS-2000 communication service and an HDR (High Data Rate) data communication service. The receiver part of the communication station includes first and second RF (Radio Frequency) receive portions, separately tunable to communicate pursuant to the communication services. A hard handover of communication is not required to be effectuated to receive one, or the other, of the services.

Abstract: The present invention relates to systems and methods that facilitate compensating for intersymbol interference (e.g. due to non-nyquist filtering) in Code Division Multiple Access (CDMA) systems (e.g., IS 95 and IS2000 systems). The subject invention employs equalization filters (e.g., T-spaced equalizers) at fingers of a RAKE receiver. By effecting such equalization filtering at a downstream point in a receiving system, e.g., at the fingers of the RAKE receiver, the filters can be run so as to operate at lower rates as compared to conventional systems where filtering is effected upstream where time is not necessarily known thus requiring equalization filters to operate at significantly faster rates (e.g., 2× or 4× expected chip rate). Accordingly, as compared to conventional systems where the matching filters often are of substantial complexity (e.g., >80 taps) the present invention provides for less complex equalization filters thereby reducing overall system complexity and cost.

Abstract: Bit probability estimates generated by a turbo decoder are employed to weight the bits of a received packet before combining the received packet with a redundant packet. Bits are individually weighted by the corresponding bit probability estimate and all bits within the received packet are weighted by a block confidence estimate generated from the cumulative bit probability estimates for the received packet. Weighted packet bits are combined within either weighted packet bits for the redundant packet or unweighted received bits for the redundant packet. The bits are combined by adding counterpart weighted (or weighted and unweighted) systematic and parity bit values within the two packets while inserting disjoint parity bit values within the combined result. Decoding performance for incremental redundancy systems utilizing turbo decoding is improved.

Abstract: Apparatus, and an associated method, for a packet radio communication system that utilizes a packet retransmission scheme. A data packet, together with a selected number of retransmissions thereof are sent to a mobile station, or other receiving station. A channel condition estimator estimates channel conditions on the communication channel and, responsive to the channel condition estimates, selection is made of the number of packet data retransmissions that are to be effectuated prior to performing decoding operations to recover the informational content of the data packet.

Abstract: A system and method for canceling interference present in a code-division multiple access (CDMA) channel signal received at a CDMA receiver that is caused by multipath components of a transmitted pilot channel signal or by soft handoff conditions is computationally efficient because it operates at symbol rates. The channel signal from which such multipath interference is canceled can be either a traffic (data) channel or the pilot channel itself. Interference signals are produced in groups corresponding to the fingers of the CDMA rake receiver. The interference signals corresponding to each finger are used to cancel interference in the other fingers.

Abstract: Apparatus, and an associated method, for effectuating power control in a radio communication system, such as an IS-95/IS-2000 system which deploys 1xEV-DO technology. At a mobile station, a channel indicia measurer measures channel conditions upon a radio link. Responsive thereto, a data rate selector selects a data rate at which subsequent data is to be communicated to the mobile station. The selection is returned to the network part of the communication system. A selector selects the power level at which to communicate the subsequent data to the mobile station responsive to the requested data rate. The requested data rate is used as a metric by which to select the power level at which to communicate the subsequent data to the mobile station.

Abstract: A code division, multiple access (CDMA) receiver includes an RF section for receiving a CDMA signal through a channel; a circuit for determining an instantaneous total received power (Io) of the received CDMA signal; and a searcher that is one of enabled for operation or disabled from operation in accordance with value of Io. The circuit includes a comparator for comparing Io against a threshold, and for generating a searcher trigger signal only when Io exceeds the threshold or, preferably, for generating the searcher trigger signal if Io does not exceed the threshold, within some predetermined period of time.

Abstract: The present invention encompasses an electronic device operated in a communication system (for example 1XEV-DO, 1XEV-DV, CDMA, etc). The electronic device receiving a signal from a base station, the signal containing signaling information and data packets. The electronic device processing portion of the signal during the current frame and simultaneously storing the received signal prior to de-spreading, for further processing during the following frame. The electronic device further processing previously stored signal, during current frame.

Abstract: A method and apparatus, such as a radiotelephone, operates so as to (a) decode a signal received from a communications channel to extract data therefrom, the data being received at one of n rates and the signal being decoded at each of the n rates for generating n Cumulative Metrics; (b) defines a matrix M composed of n mean vectors derived from the n Cumulative Metrics; (c) orthogonalizes the n rates by inverting the matrix M and multiplying with an observable vector of Cumulative Metrics to obtain a discriminant vector; and (d) determining the correct rate from the discriminant vector as the row number having a maximum value. One or both of a fixed or an adaptive scaling can be applied to the soft data prior to Viterbi decoding, and the resulting Cumulative Metrics can be scaled again to undo the first scaling, prior to operation of the rate determination technique.

Abstract: Bit probability estimates generated by a turbo decoder are employed to weight the bits of a received packet before combining the received packet with a redundant packet. Bits are individually weighted by the corresponding bit probability estimate and all bits within the received packet are weighted by a block confidence estimate generated from the cumulative bit probability estimates for the received packet. Weighted packet bits are combined within either weighted packet bits for the redundant packet or unweighted received bits for the redundant packet. The bits are combined by adding counterpart weighted (or weighted and unweighted) systematic and parity bit values within the two packets while inserting disjoint parity bit values within the combined result. Decoding performance for incremental redundancy systems utilizing turbo decoding is improved.

Abstract: Apparatus, and an associated method, by which to facilitate regulation of power levels of a communication signal generated during operation of a communication system. Closed-loop power control is effectuated by selectively generating a power control command such as a power up or power down command responsive to calculated time rates of change of a calculated difference value. By generating a power command responsive to calculations of time rates of change, earlier decisions are made of the power control commands than conventionally permitted in conventional closed-loop power control schemes.

Abstract: A wireless telecommunications mobile station, which is bi-directionally coupled to a base station through a communication channel, includes a device for receiving signals over the communication channel from the base station, power control circuitry for selectively deriving power control commands, and a device for transmitting the selectively derived power control commands to the base station. The power control circuitry of the mobile station provides, in cooperation with power control circuitry of the base station, closed loop power control to the communication channel. The power control circuitry includes circuitry for selectively deriving power control commands based on one of first power control commands or second power control commands in response to a determined mobility of the mobile station. The determined mobility can be indicative of a Doppler shift of carrier transmitted from the base station, or a velocity derived from the Doppler shift.

Abstract: A method and apparatus of assigning fingers in a rake receiver for incorporation in a receiver of a CDMA communications system is disclosed herein. The method includes measuring the multipath profile of a received spread-spectrum radio-frequency (RF) signal to obtain a sequence of measurements, identifying the best candidate path of the RF signal to demodulate by determining which measurement within the sequence has the highest signal strength, deriving a timing offset for the best candidate path as a function of the measurement for the best candidate path and its adjacent measurements, and assigning a finger processing element to the best candidate path using the derived timing offset. The measurements are taken using a searcher having a predetermined timing resolution (e.g., ½ chip), and the resolution of the timing offset is higher (e.g., ⅛ chip). The best candidate path to demodulate is identified using the measurement having the highest amplitude or correlation function.

Abstract: The invention provides a digital x-ray mammography device capable of imaging a full breast. A movable aperture coupled with a movable x-ray image detector permits x-ray image data to be obtained with respect to partially overlapping x-ray beam paths from an x-ray source passing through a human breast. A digital computer programmed with a stitching algorithm produces a composite image of the breast from the image data obtained with respect to each path. In a preferred embodiment, a Schmidt camera images visible light produced at an x-ray to visible light conversion surface onto a digital detector array to produce an overlapping image pane with respect to each overlapping beam path.