Abstract: Techniques to reduce LO leakage by controlling the amplitude of LO signal based on the level of output signal after the frequency conversion process. An LO generator receives a VCO signal and generates an LO signal having a variable amplitude and a frequency that is related to the frequency of the VCO signal. A variable gain amplifier receives a control signal and adjusts the amplitude of the LO signal based on the control signal. The variable amplitude LO signal is used for frequency upconversion (e.g., direction upconversion) of an input signal (e.g., at baseband) to obtain an output signal (e.g., at RF). The relationship between LO signal amplitude and output signal level may be defined by a particular transfer function. In general, the LO signal is set higher for higher output signal level and is reduced proportionally for lower output signal level.

Abstract: A voice recognition system applies speaker-dependent modification functions to acoustic feature vectors prior to voice recognition pattern matching against a speaker-independent acoustic model. An adaptation engine matches a set of acoustic feature vectors X with an adaptation model to select a speaker-dependent feature vector modification function f( ), which is then applied to X to form a modified set of acoustic feature vectors f(X). Voice recognition is then performed by correlating the modified acoustic feature vectors f(X) with a speaker-independent acoustic model.

Abstract: A signal conditioning circuit is described which can facilitate dual mode use of a connector circuit, e.g., audio mode or data mode. In other words, a headset or alternatively, a data interface may be coupled to the connector circuit and signal conditioning circuit, depending on the mode of the device. In accordance with this disclosure, the signal conditioning circuit operates in audio mode without the need for conventional blocking capacitors in the speaker channels. Moreover, in some embodiments, the signal conditioning circuit also provides backwards compatibility with conventional connector circuits that include such blocking capacitors.

Abstract: A time-varying transformation is used to correlate the magnitude of the interference between multiple antenna paths. Embodiments incorporating the time-varying transformations provide transmit diversity gains to remote stations that are not configured for transmit diversity reception. In addition, some of the embodiments can be further configured to balance the load between multiple power amplifiers.

Abstract: A battery monitoring apparatus that senses battery conditions such as low battery charge, end of battery capacity, and end of battery life, and responds by taking actions such as sending messages to a remote site and/or powering down. A rechargeable battery is coupled to one or more power-consuming electrical components, including battery monitoring equipment. The battery monitoring equipment senses battery charge. In response to a low-battery-charge condition, the battery monitoring equipment transmits a battery status message to a remote site and powers-down some of the electrical components. Whenever the battery nears the end of its capacity, the monitoring equipment powers down all electronic components and awaits the application of external power. The invention also tracks the time required for the battery charge to deplete. Charge duration decreases over time, and whenever it reaches a predetermined minimum, the battery monitoring equipment transmits a representative status message to the remote site.

Abstract: A method is taught for transmitting message signals in a communication system having a new call entering the communication system and Walsh codes that can be active and inactive. The method includes dividing the Walsh codes into bins and determining the number of active Walsh codes in the bins. Selecting a Walsh code in accordance with the Walsh code number determination and assigning the selected Walsh code to the new call are set forth.

Abstract: Techniques for scalable CDMA demodulation with maximum response latency are disclosed. In one aspect, a finger timing unit generates signals indicating cycle boundaries for a plurality of fingers, and an offline processing unit processes stored samples for those fingers in response to the signals. In another aspect, incoming samples are stored in a RAM, while finger timing is maintained using a plurality of counters. The RAM address is stored on symbol boundaries. Symbols for each finger are generated in an offline processing unit, clocked at a higher speed than the finger counters, from a RAM location computed using the stored RAM address. Various other aspects are also presented. These aspects provide for decoupling of the chip rate processing from chip time, which allows a single offline processing unit to service a plurality of fingers, thus reducing additional hardware required to support additional fingers while maintaining maximum latency requirements.

Abstract: A searcher is centered on frequency bins to search for an incoming signal. The frequency locked loop generates an initial phase signal and a phase increment signal that are input to an accumulator. The accumulator accumulates the phase increments over a predetermined interval. After the interval, the accumulator generates a control signal that instructs a rotator to perform a phase rotation function.

Abstract: Techniques to acquire pilots over code space and/or frequency errors. In one aspect, pilot acquisition is performed using a number of substages, and some of the substages are pipelined and performed in parallel using different processing elements. A searcher initially searches over a designated code space to find peaks, and these peaks may be re-evaluated. Finger processors then attempt to acquire the candidate peaks. The searcher may be operated to search for the next set of peaks while the finger processors process the current set of peaks. In another aspect, the full range of frequency errors for the pilots is divided into a number of frequency bins. A multi-stage scheme is used to evaluate the bins, and may employ pipelining and parallel processing such that a search for peaks in the next bin is performed while acquisition of peaks found for the current bin is attempted.

Abstract: An outer decoder and an inner decoder encode a block of information to be transmitted, to improve protection by adding redundancy. The redundancy permits decoding of the information from less than a complete encoded block of information. Time re-alignment of two transmissions of the same content from two base stations can mitigate the problem of clipped frames. The user of the subscriber station can experience seamless service without loss of content, even when handing over to a new cell while receiving a buffer of broadcast content.

Abstract: An outer decoder and an inner decoder encode a block of information to be transmitted, to improve protection by adding redundancy. The redundancy permits decoding of the information from less than a complete encoded block of information. Time re-alignment of two transmissions of the same content from two base stations can mitigate the problem of duplicated frames. The user of the subscriber station can experience seamless service without repetition of content, even when handing over to a new cell while receiving a buffer of broadcast content.

Abstract: A method and apparatus for controlling transmission power levels in a mobile communication system. The method provides for a closed-loop power control method. A mobile station provides information on the quality of the signal received from the base station, and the base station responds by adjusting the power allocated to that user in a shared base station signal. The transmission power is adjusted initially by a large increment and then ramped down at an increasingly decreasing rate. The mobile station also provides information to the base station as to its relative velocity and the base station adjusts its transmission power in accordance with this velocity information.

Abstract: Techniques for efficient W-CDMA modulation are disclosed. In one aspect, a multiplexing/coding chain for use in modulation such as that defined by the W-CDMA specification is disclosed. In another aspect, transport blocks are processed and concatenated, utilizing memory efficiently. This aspect has the further benefit of preparing transport channels for efficient subsequent processing. It also allows for ease of interface with the transport channel source. In another aspect, the use of repeated channel coding is used in lieu of an interleaver memory to provide channel coding and interleaving. These aspects, collectively, yield the advanced benefits of a system, such as W-CDMA, in a hardware efficient manner. The techniques described herein apply equally to both access points and access terminals. The techniques are not limited to W-CDMA systems; they are quite suitable to other systems requiring the various benefits the invention offers. Various other aspects of the invention are also presented.

Abstract: Techniques to support adaptive multi-rate (AMR) coded data in a cdma2000 communication system. A number of AMR modes are defined for speech information (of various rates), silence descriptor (SID) (of various types), and blank frame. The speech and SID data are provided in frames conforming to frame formats defined by the cdma2000 system. A CRC is used for each AMR frame (e.g., 12-bit CRC for speech and 8-bit CRC for SID). The AMR data and CRC bits are further coded with a convolutional encoder. Blind rate detection is used to detect the frame rate of the transmitted AMR frames. To support blind rate detection, the number of bits provided to the CRC generator is different for each blind rate to be detected. If two or more blind rates have the same number of bits (such as for SID), then format bits are provided to distinguish between these rates.

Abstract: A method and apparatus for coordinating the time at which a mobile station performs searches for alternative systems to which a hard handoff will occur. The mobile station receives a command which instructs the mobile station as to when to tune to alternative frequencies in order to search for indicates of the presence of an alternative system. In another system which includes the present invention, predetermined times are defined with respect to a reference point in time that is common to both the origination base station and a mobile station. The mobile station tunes to alternative frequencies to perform searches only during these predetermined times. In addition, the mobile station coordinates the transmission of reports, which indicate the results of searches for alternative systems such that these reports are only transmitted from the mobile station when the mobile station is tuned to the origination frequency.

Abstract: A power estimator for a Code Division Multiple Access (CDMA) receiver. A noise estimate of a received channel may be made by demodulating a received signal using an empty code or Walsh channel. The noise estimate may also be made by demodulating the Pilot signal in systems where potentially all Walsh codes are assigned to active channels. Where the channels are quadrature phase modulated, the noise estimator may take advantage of the Pilot channel configuration by demodulating only the quadrature element of the Pilot channel. The noise estimator demodulates the Pilot using signal processing stages that statistically correspond to the signal processing performed on traffic channels. The statistics of the processing performed in the noise estimate closely track the statistics of the signal processing performed on the traffic channels.

Abstract: A system and method for adjusting forward traffic channel power allocation in a communications system, wherein signal qualities of pilot channels respectively transmitted by multiple base stations in an active set of a mobile station, are measured by the mobile station, compared to a signal quality standard, and the comparison results reported to a system controller, thereby to indicate which of the pilots at the mobile station surpass the standard. The system controller then adjusts the forward channel power allocation based on the comparison results.

Abstract: Techniques for power control that avoids outer loop wind-up are disclosed. In one aspect, wind-up of a target power level is detected, and the target power level is modified in response. In another aspect, unwinding of the target power level is detected, after which the target power level is determined without considering wind-up. Various other aspects are also presented, including wind-up and unwinding detection procedures, and target power level modification procedures. These aspects have the benefit of reducing the time that transmit power exceeds that which is necessary, thus increasing system capacity and performance, and mitigating misallocation of system resources.

Abstract: In a disclosed embodiment, a maintain and adjust threshold module determines the desired signal to noise and interference ratio for a first channel. Next, a delta computation module produces a threshold delta, which is then added to a base threshold by way of an adder. The resulting sum is the outer-loop set point that is used in a comparator. The comparator compares a receive signal strength with the outer-loop threshold. The comparator output is inputted to a generate up/down command module. The generate up/down command module sends a down command to the mobile unit if receive signal strength is greater than the outer-loop threshold, otherwise it sends an up command.

Abstract: Techniques for time tracking diversity pilots are disclosed. In one aspect, an early and a late energy calculation is made on each incoming symbol using a first pilot sequence for despreading. The difference between the two energies is used to drive a tracking loop, which generates a time reference for producing a first pilot estimate and a second pilot estimate, the two estimates used for demodulating data. In another aspect, the early and late energies are made including a plurality of incoming symbols, the number of which corresponds to the number of symbols in a run of positive or negative values in an orthogonalizing sequence. The orthogonalizing sequence is used to generate a second pilot sequence from a first pilot sequence, the resulting second pilot sequence being orthogonal to the first. These aspects have the benefit of simplifying the hardware or processing steps required for transmit diversity time tracking, resulting in cost savings, power savings, simplicity of design, and the like.