Abstract: A wireless mobile telephone (400) is operated so as manage the performance of “off-frequency searches,” that is, searches for base station pilot signals that differ in frequency from the pilot signals in the mobile station's active set. Whenever frequency searching is performed (such as responsive to emerging from a reduced-power sleep mode), the mobile station performs on-frequency pilot signal searching (902) upon a prescribed active set frequency. Only if a prescribed off-frequency searching condition (903-908) is satisfied, the mobile station additionally performs off-frequency pilot signal searching (912) upon one or more neighboring base stations' frequencies.

Abstract: A novel and improved method and apparatus provide for controlling an operation of an access terminal while processing a signal from an access point in a communication system. Various aspects of the invention provide for an access terminal to disable a handoff process when its demodulator or decoder is operating to demodulate or decode a control message received from an access point. The operation of the access terminal is controlled in a manner that prevents terminating prematurely the demodulation and decoding process of a control signal by a handoff process. As a result, the access terminal may continue operating in a normal wake up/ sleep cycle period while conserving its battery power.

Abstract: In an antenna diversity environment, the timing offset of the receiver's fingers are based on the timing offset of the received peaks of the base station transmit signals. In a system with non-negligible multipath spacing, the timing offset of the received peaks of the base station transmit signals are not necessarily at the same location. In one embodiment, the demodulating elements for the signal from each base station antenna use the same offset for demodulating and determining an error signal based on pilot signal sampling prior to the timing offset and subsequent to the timing offset. The error signals are averaged and used by a time tracking loop to track the incoming signal. In another embodiment, the demodulating elements for the signal from each base station antenna independently time track the signals with different timing offsets for each finger. The preferred embodiment depends on the method used by the base station to multiplex the data onto multiple transmit antennas.

Abstract: In an antenna diversity environment, the timing offset of the receiver's fingers are based on the timing offset of the received peaks of the base station transmit signals. In a system with non-negligible multipath spacing, the timing offset of the received peaks of the base station transmit signals are not necessarily at the same location. In one embodiment, the demodulating elements for the signal from each base station antenna use the same offset for demodulating and determining an error signal based on pilot signal sampling prior to the timing offset and subsequent to the timing offset. The error signals are averaged and used by a time tracking loop to track the incoming signal. In another embodiment, the demodulating elements for the signal from each base station antenna independently time track the signals with different timing offsets for each finger. The preferred embodiment depends on the method used by the base station to multiplex the data onto multiple transmit antennas.

Abstract: A multi-carrier filter for a wireless communications system employing a multi-carrier signal. The multi-carrier filter includes a first mechanism for receiving the multi-carrier signal and extracting carrier signal components of the multi-carrier signal in response thereto. A second mechanism filters the carrier signal components and outputs a demodulated and filtered multi-bandwidth signal in response thereto. In the specific embodiment, the first mechanism includes a rotator. The multi-carrier signal is a 3× bandwidth multi-carrier signal having three carrier components. The three carrier components include a center carrier, a left carrier, and a right carrier. The center carrier, the left carrier, and the right carrier are separated by approximately 1.25 MHz. The rotator is a lookup table rotator that includes a mechanism for selectively rotating the multi-carrier-signal clockwise or counter clockwise and outputting the left carrier or the right carrier, respectively, in response thereto.

Abstract: Techniques to efficiently attempt acquisition of a packet data system (e.g., an IS-856 system). If a terminal has acquired one or more channels in a voice/data system (e.g., an IS-2000 system), then it can attempt acquisition on channels in the packet data system that are co-located with the acquired channels in the voice/data system. Multiple acquisition modes may be used, and on-going acquisition attempts on the co-located channels may be performed using one acquisition mode at a time in order to reduce power consumption. Acquisition attempts may be performed in a “ping-pong” manner to improve the likelihood of acquisition. For a ping-pong search, an acquisition attempt is made on the most recently acquired channel prior to an acquisition attempt on each of the remaining channels. Received signal strength estimates may also be obtained for selected channels and may be used to determine whether or not to attempt acquisition on these channels.

Abstract: Demodulator architectures for processing a received signal in a wireless communications system. The demodulator includes a number of correlators coupled to a combiner. Each correlator typically receives and despreads input samples (which are generated from the received signal) with a respective despreading sequence to provide despread samples. Each correlator then decovers the despread samples to provide decovered “half-symbols” and further demodulates the decovered half-symbols with pilot estimates to generate correlated symbols. The decovering is performed with a Walsh symbol having a length (T) that is half the length (2T) of a Walsh symbol used to cover the data symbols in the transmitted signal. The combiner selectively combines correlated symbols from the assigned correlators to provide demodulated symbols. One or more correlators can be assigned to process one or more instances of each transmitted signal.

Abstract: Demodulator architectures for processing a received signal in a wireless communications system. The demodulator includes a number of correlators coupled to a combiner. Each correlator typically receives and despreads input samples (which are generated from the received signal) with a respective despreading sequence to provide despread samples. Each correlator then decovers the despread samples to provide decovered “half-symbols” and further demodulates the decovered half-symbols with pilot estimates to generate correlated symbols. The decovering is performed with a Walsh symbol having a length (T) that is half the length (2T) of a Walsh symbol used to cover the data symbols in the transmitted signal. The combiner selectively combines correlated symbols from the assigned correlators to provide demodulated symbols. One or more correlators can be assigned to process one or more instances of each transmitted signal.

Abstract: The velocity of a wireless communications device (WCD) (106) is estimated. In response to this estimate a power control command rate is determined. The WCD 106 transmits power control signals to a base station (102) according to the power control command rate. The power control command rate may be determined by mapping the estimated velocity to a velocity range, and selecting a rate that corresponds to the velocity range as the power control command rate. Velocity is estimated by measuring a level crossing rate of a multipath signal.

Abstract: A multi-carrier filter for a wireless communications system employing a multi-carrier signal. The multi-carrier filter includes a first mechanism for receiving the multi-carrier signal and extracting carrier signal components of the multi-carrier signal in response thereto. A second mechanism filters the carrier signal components and outputs a demodulated and filtered multi-bandwidth signal in response thereto. In the specific embodiment, the first mechanism includes a rotator. The multi-carrier signal is a 3× bandwidth multi-carrier signal having three carrier components. The three carrier components include a center carrier, a left carrier, and a right carrier. The center carrier, the left carrier, and the right carrier are separated by approximately 1.25 MHz. The rotator is a lookup table rotator that includes a mechanism for selectively rotating the multi-carrier-signal clockwise or counter clockwise and outputting the left carrier or the right carrier, respectively, in response thereto.

Abstract: In an antenna diversity environment, the timing offset of the receiver's fingers are based on the timing offset of the received peaks of the base station transmit signals. In a system with non-negligible multipath spacing, the timing offset of the received peaks of the base station transmit signals are not necessarily at the same location. In one embodiment, the demodulating elements for the signal from each base station antenna use the same offset for demodulating and determining an error signal based on pilot signal sampling prior to the timing offset and subsequent to the timing offset. The error signals are averaged and used by a time tracking loop to track the incoming signal. In another embodiment, the demodulating elements for the signal from each base station antenna independently time track the signals with different timing offsets for each finger. The preferred embodiment depends on the method used by the base station to multiplex the data onto multiple transmit antennas.