Abstract: A method for clock synchronization in a communication system having first circuitry coupled to a first communication channel and second circuitry, includes generating a first timing synchronization parameter, and synchronizing the second circuitry to a second communication channel using the first timing synchronization parameter.

Abstract: A method for clock synchronization in a communication system having first circuitry coupled to a first communication channel and second circuitry, includes generating a first timing synchronization parameter, and synchronizing the second circuitry to a second communication channel using the first timing synchronization parameter.

Abstract: A method for clock synchronization in a communication system having first circuitry coupled to a first communication channel and second circuitry, includes generating a first timing synchronization parameter, and synchronizing the second circuitry to a second communication channel using the first timing synchronization parameter.

Abstract: A method for clock synchronization in a communication system having first circuitry coupled to a first communication channel and second circuitry, includes generating a first timing synchronization parameter, and synchronizing the second circuitry to a second communication channel using the first timing synchronization parameter.

Abstract: A decision feedback equalizer includes a chip estimate buffer that forms chip estimates into a vector. A CCK decoder decodes the vector of chip estimates, and a CCK encoder, connected with the CCK decoder, re-encodes the vector of chip estimates into a valid CCK code word. At the same time, a chip slicer provides direct sliced chips from the chip estimates. An update module then forms a hybrid vector from the valid CCK code-word and the direct sliced chips for input to the feedback filter of the decision feedback equalizer. The hybrid feedback filter input vector reflects the CCK coding gain of its re-encoded portion thereby reducing the estimated chip error rate to improve the performance of the decision feedback equalizer.

Abstract: In a remote unit of a wireless communication system, the speed of acquisition, or reacquisition, of a pilot signal by a search engine is increased. PN space is divided into segments and a coarse search of each segment is performed using a set of “fast” search parameters. A set of peak signal strengths, along with their corresponding PN offsets, is saved for each segment of PN space. Following the search of all segments of PN space, the peak signal strengths which were saved during the coarse acquisition are evaluated. Coarse acquisition search results are used by the remote unit to determine fine search window parameters for subsequent searches performed by the remote unit search engine. The fine search parameters concentrate searching efforts on portions of PN space most likely to contain a viable base station pilot signal.

Abstract: Techniques for performing time tracking at a receiver are described. A first arriving path (FAP) and a last arriving path (LAP) are detected based on a channel impulse response estimate for a communication channel. The detected FAP and LAP may be correct or swapped. To resolve ambiguity in the detected FAP and LAP, a first hypothesis corresponding to the FAP and LAP being correctly detected and a second hypothesis corresponding to the FAP and LAP being incorrectly detected are evaluated. For each hypothesis, hypothesized FAP and LAP are determined based on the detected FAP and LAP, a correlation window is determined based on the hypothesized FAP and LAP, and correlation is performed using the correlation window. The correct hypothesis is determined based on correlation results for the two hypotheses. The receiver timing is updated based on the hypothesized FAP and LAP for the correct hypothesis and used for demodulation.

Abstract: Techniques for detecting mode and guard length and estimating timing offset for an OFDM transmission are described. Multiple hypotheses for different combinations of mode and guard length that might have been used for the OFDM transmission are evaluated. For each hypothesis, correlation is performed on received samples for a hypothesized guard interval to obtain correlation results. The energy of the hypothesized guard interval is determined. A first metric is derived based on the correlation results and the energy. The first metric may be filtered, e.g., averaged. Noise is estimated, e.g., based on a set of elements for the filtered first metric at locations determined by an estimated timing offset for the hypothesis. A second metric is derived based on the filtered first metric and the estimated noise. The second metric for all hypotheses may be used to determine the mode, guard length, and timing offset for the OFDM transmission.

Abstract: Techniques for operating two receivers to receive data and paging from two systems are described. A primary receiver is associated with better performance than a secondary receiver under poor RF conditions. The two receivers may be operated in either a hybrid mode in which the primary receiver is used to receive paging or a simultaneous mode in which the second receiver is used to receive paging. One of the modes may be selected for use based on RF conditions, received power, demodulation metrics, and/or other criteria. In one design, a mode is selected based on the received power and one or more thresholds. In another design, the hybrid mode is selected for poor RF conditions and, for good RF conditions, the hybrid or simultaneous mode is selected based on received power.

Abstract: A system and method for detecting discontinuous transmission (DTX) frames. The inventive method includes the steps of receiving data transmitted in a plurality of frames; classifying each of the frames; analyzing the classification of a number of successive frames of the received data and providing a metric with respect thereto; and determining, in response to the metric, if a frame is a discontinuous frame. In the illustrative embodiment, the step of classifying includes the step of error checking the frames using a cyclic redundancy check (CRC) error checking protocol. The received frames are classified as good frames (G), erasure frames (E), or discontinuous frames (D). A numerical value is assigned to each of the frames based on the classification thereof. Next, the frames are filtered to provide an output Yn=Yn?1+Xn where ‘n’ is a frame number, Yn is the filter output for a given frame n, Yn?1 is the filter output for a previous frame, and Xn is a stream of input frames.

Abstract: A method for localizing a mobile station, which in one embodiment is characterized by logging one or more wireless channels which belong to one or more network providers other than the mobile station's home network provider and which substantially currently provide communication with one or more discernable base stations; and establishing a geographic position of the mobile station by use of the one or more wireless channels which belong to the one or more network providers other than the mobile station's home network provider. In one or more various embodiments, related systems include but are not limited to circuitry and/or programming for effecting the foregoing-referenced method embodiment, the circuitry and/or programming can be virtually any combination of hardware, software, and/or firmware configured to effect to foregoing-referenced method embodiment depending upon the design choices of the system designer.

Abstract: A system and method of conducting wireless communications between a wireless communication device (WCD) and both a first network (e.g., IS-2000) supporting voice and data services and a second network (e.g., IS-856) supporting packet data services. The method comprises providing the WCD with a primary transceiver and a secondary receiver for conducting wireless communications in a spatial diversity for the second network traffic or broadcast; disabling the secondary receiver and spatial diversity before a paging slot or 1x system acquisition and synchronization attempts; tuning the secondary receiver to a first network carrier frequency to perform first network activities; and retuning the secondary receiver to a second network carrier frequency for spatial diversity after performing the first network activities. The first network activities may include pilot set maintenance, overhead message maintenance, page match detection, or 1x system acquisition and synchronization attempts.

Abstract: A system and method of improving wireless communications between a wireless communication device and both a first network supporting voice and data services and a second network supporting packet data services. The method comprises providing the WCD with a primary transceiver and a secondary receiver for conducting wireless communications in both a simultaneous-mode and a hybrid-mode; performing simultaneous-mode-to-hybrid-mode and hybrid-mode-to-simultaneous-mode transitions based on a performance metric; and evaluating the performance metric to determine whether to perform the mode transitions. In the simultaneous-mode, the primary transceiver conducts wireless communications in the second network and the secondary receiver conducts wireless communications in the first network. In the hybrid-mode, the primary transceiver use is time multiplexed during all of the first and second networks communications combinations.

Abstract: The present invention provides a method and apparatus for maximizing throughput of a data call in a wireless communication system in which data is transmitted from a wireless station, such as a mobile station, on multiple assigned channels in accordance with a known transmission standard, such as IS-95B. The multiple assigned channels include a fundamental channel and at least one supplemental channel. Data is formatted into variable rate data frames and transmitted on the fundamental channel and the supplemental channel. A wireless receiver, such as a base station, receives the multiple assigned channels. The wireless receiver demodulates and decodes data frames associated with each of the multiple assigned channels. The wireless receiver determines a likely initial data rate for each demodulated and decode data frame.

Abstract: The present invention provides a method and apparatus for maximizing throughput of a data call in a wireless communication system in which data is transmitted from a wireless station, such as a mobile station, on multiple assigned channels in accordance with a known transmission standard, such as IS-95B. The multiple assigned channels include a fundamental channel and at least one supplemental channel. Data is formatted into variable rate data frames and transmitted on the fundamental channel and the supplemental channel. A wireless receiver, such as a base station, receives the multiple assigned channels. The wireless receiver demodulates and decodes data frames associated with each of the multiple assigned channels. The wireless receiver determines a likely initial data rate for each demodulated and decode data frame.

Abstract: A decision feedback equalizer includes a chip estimate buffer that forms chip estimates into a vector. A CCK decoder decodes the vector of chip estimates, and a CCK encoder, connected with the CCK decoder, re-encodes the vector of chip estimates into a valid CCK code word. At the same time, a chip slicer provides direct sliced chips from the chip estimates. An update module then forms a hybrid vector from the valid CCK code-word and the direct sliced chips for input to the feedback filter of the decision feedback equalizer. The hybrid feedback filter input vector reflects the CCK coding gain of its re-encoded portion thereby reducing the estimated chip error rate to improve the performance of the decision feedback equalizer.

Abstract: An apparatus, such as a subscriber unit or a base station within a spread spectrum communication system, may add one or more additional “virtual” paths to a list of candidate paths when assigning demodulation elements. These “virtual” paths are added as candidate paths even though a corresponding peak was not necessarily detected within a received spread spectrum system. The list of paths may include a first path having a time offset approximately equal to a time offset for one of the demodulation elements, and the virtual path having a short time separation from the first path. The time separation between the paths may be, for example, less than 2 chips.

Abstract: A method for localizing a mobile station, which in one embodiment is characterized by: logging one or more wireless channels which belong to one or more network providers other than the mobile station's home network provider and which substantially currently provide communication with one or more discernable base stations; and establishing a geographic position of the mobile station by use of the one or more wireless channels which belong to the one or more network providers other than the mobile station's home network provider.

Abstract: A spread spectrum wireless device (100) may include a receiver (110), a searcher (128), a search controller (130) and other features. The search controller (130) selectively generates control signals to control the searcher (128), which searches for a spread-spectrum signal. In one embodiment, the architecture of the searcher (128) is dynamically configurable by the search controller (130) to selectively search multiple channels using multiple frequency bins for the signal.

Abstract: A quick paging channel (QPCH) is used to receive paging indicators that indicate that a wireless communication device (WCD) has a message on a paging channel relating to, for example, an incoming call to the WCD. When the condition of the quick paging channel is too low to receive paging indicators reliably, the quick paging channel is disabled to avoid false alarms, and the slotted paging channel is used to receive paging messages without monitoring the QPCH. When the QPCH signal is strong, the probability of false alarms is lower, and the quick paging channel is enabled. By using the quick paging channel to receive paging indicators only when the QPCH signal is strong, the wireless communication device can remain in a sleep state for greater periods of time as compared with the use of a slotted paging channel. As a result, standby time may be significantly improved.