Abstract: A dual-path current amplifier having a slow high-gain path and a fast low-gain path is described. In one design, the slow high-gain path is implemented with a positive feedback loop and has a gain of greater than one and a bandwidth determined by a pole. The fast low-gain path has unity gain and wide bandwidth. The two signal paths receive an input current and provide first and seconds currents. A summer sums the first and second currents and provides an output current for the dual-path current amplifier. The dual-path current amplifier may be implemented with first and second current mirrors. The first current mirror may implement the fast low-gain path. The first and second current mirrors may be coupled together and implement the slow high-gain path. The first current mirror may be implemented with P-FETs. The second current mirror may be implemented with N-FETs, an operational amplifier, and a capacitor.

Abstract: A method and system for link latency determination in a Mobile IP network determine an unloaded network delay; set a current estimated delay; initiate a current round trip estimation process; and set a retry timer. If the retry timer expires before the process completes, the method and system update the predetermined backoff period and repeat the preceding two steps. After re-registration, the method and system reset the current estimated delay time. The link latency determination optimizes the re-registration process between a mobile device and an agent device, thereby enhancing mobile device communications, minimizing network loading, and optimizing network traffic levels.

Abstract: A dual path loop filter circuit for a phase lock loop is described. The filter circuit allows the filter to be integrated into a phase lock loop IC circuit without using active circuit components that may create additional noise and consume additional power. The filter circuit structure allows for a low capacitance capacitor to be used to filter out any undesired signals.

Abstract: Techniques for performing timer-based sleep to extend sleep time and thus battery life for a terminal in a wireless communication system. The likelihood of data traffic may be related to recent usage. If recent usage indicates that data traffic is unlikely, then the terminal can continue to maintain the link but monitor the signals from the system at a reduced rate. In one method, the probability of data traffic for the terminal is initially estimated (e.g., based on time since last activity and a particular usage model). A timer value is then determined based on the estimated probability of data traffic. The timer value may be modified based on an event, which may relate to link maintenance, hand-off, and so on. Sleep is then performed for the duration corresponding to the unmodified or modified timer value and may extend past one or more designated paging slots.

Abstract: For coverage determination and system switching, a terminal obtains pilot strength estimates for base stations in first and second wireless communication systems (e.g., packet data system and voice/data system) and received signal quality estimates for at least one serving base station in the first system. The terminal derives various metrics based on the received signal quality estimates and pilot strength estimates. The terminal may perform handoff to the second system if weak coverage is detected for the first system, a received signal quality metric (Q) for the first system is below a Qth—dn threshold, and a pilot strength metric (V) for the second system exceeds a Vth—dn threshold. The terminal may perform handoff to the first system if good coverage is detected for this system, metric Q exceeds a Qth—up threshold, or a maximum pilot strength metric (M) for the first system exceeds a Mth—up threshold.

Abstract: An integrated circuit includes multiple power domains. Supply current switch circuits (SCSCs) are distributed across each power domain. When a signal is present on a control node within a SCSC, the SCSC couples a local supply bus of the power domain to a global supply bus. An enable signal path extends through the SCSCs so that an enable signal can be propagated down a chain of SCSCs from control node to control node, thereby turning the SCSCs on one by one. When the domain is to be powered up, a control circuit asserts an enable signal that propagates down a first chain of SCSCs. After a programmable amount of time, the control circuit asserts a second enable signal that propagates down a second chain. By spreading the turning on of SCSCs over time, large currents that would otherwise be associated with coupling the local and global buses together are avoided.

Abstract: Techniques to mitigate spikes in transmit power, by reducing the magnitude and/or duration of the spikes, are described. Initially, power control is performed in a normal manner and in accordance with a transmit power control (TPC) scheme. If a (e.g., upward) transmit power spike is detected, the power control is performed in a manner to mitigate the adverse effects of the spike and in accordance with another TPC scheme. An upward transmit power spike may be detected, e.g., if a predetermined number of consecutive TPC commands in the upward direction is obtained for increasing transmit power. The upward transmit power spike may be mitigated by limiting the transmit power, reducing the rate of transmit power adjustment in the upward direction, delaying and/or filtering TPC decisions used for transmit power adjustment, preventing upward adjustment of transmit power, and so on. Multiple states may be defined and used to facilitate power control with spike mitigation.

Abstract: A pilot searcher for CDMA and GPS signals. In one aspect, the searcher is operated in conjunction with a sample buffer in a “real-time” or “off-line” mode. The writing/reading of samples to/from the buffer may be performed in a TDM manner via a common port, and samples may be decimated and packed prior to storing in the buffer. In another aspect, the overall search for pilots is partitioned into a number of tasks, with each task corresponding to a search over a given sample segment and based on a particular set of parameter values. The tasks may be stored in a queue and performed one at a time based on their order in the queue. Prior to performing a new task, the parameter values for that task is downloaded to a set of configuration registers. The parameters may be ordered and linked such that only new values are downloaded.

Abstract: A terminal obtains a monitored set containing GSM neighbor cells and/or UMTS neighbor cells. The terminal operates in a compressed mode and obtains from a UMTS network at least two transmission gap pattern sequences for different measurement purposes, e.g., for “GSM carrier RSSI measurements” (GAP1), “GSM initial BSIC identification” (GAP2), and “GSM BSIC re-confirmation” (GAP3). The terminal makes RSSI measurements for the GSM cells using multiple transmission gap pattern sequences, e.g., using GAP1, GAP2 and GAP3. The terminal identifies the BSIC for at least one GSM cell by (1) detecting the tone on the FCCH using multiple transmission gap pattern sequences, e.g., using GAP2 and GAP3, and (2) decoding the SCH using multiple transmission gap pattern sequences, e.g., using GAP2 and GAP3. The use of multiple transmission gap pattern sequences for RSSI measurement and BSIC identification allows the terminal to complete the cell measurements and send a report sooner, which may improve performance.

Abstract: An output stage includes two transistors (switching transistor and biasing transistor) coupled in series in a pullup current path between a VDDA node and an output node, and also includes two transistors (switching transistor and biasing transistor) coupled in series in a pulldown current path between the output node and a ground node. Providing the biasing transistors reduces the maximum voltage dropped across the transistors, thereby allowing the transistors to have lower breakdown voltages than VDDA. An adaptive biasing circuit adjusts the gate voltage on a biasing transistor based on the output node voltage. If the output voltage is in a midrange, then the gate voltage is set farther away from a rail voltage in order to reduce voltage stress. If the output voltage is in a range closer to the rail voltage, then the gate voltage is set closer to the rail voltage, thereby facilitating rail-to-rail output voltage swings.

Abstract: An HDLC accelerator includes a deframer and framer to respectively accelerate the deframing and framing processes for PPP packets. The deframer includes an input interface unit, a detection unit, a conversion unit, and an output interface unit. The input interface unit receives a packet of data to be deframed. The detection unit evaluates each data byte to detect for special bytes (e.g., flag, escape, and invalid bytes). The conversion unit deframes the received data by removing flag and escape bytes, “un-escaping” the data byte following each escape byte, providing a header word for each flag byte, and checking each deframed packet based on a frame check sequence (FCS) value associated with the packet. The output interface unit provides deframed data and may further perform byte alignment in providing the deframed data. A state control unit provides control signals indicative of specific tasks to be performed for deframing.

Abstract: In a disclosed embodiment, a “voice noise power” is added to an aggregate voice power which is the total voice power used by all users in a cell. The voice noise power is transmitted in addition to the aggregate voice power in order to maintain the total of the aggregate voice power and voice noise power at a pre-determined voice power limit. In one embodiment, the voice power limit can be increased or decreased to further improve control over power consumption during voice and data transmission. Further, in order to maintain the power consumed by data transmission at a desired level, data noise is transmitted after transmission of a data burst, or in between data bursts, by inserting a pre-determined amount of artificial data into the gaps in data transmission. The data noise is transmitted in addition to the data bursts in order to maintain the total power consumed during data transmission at a desired level.

Abstract: Techniques for Walsh space assignment are disclosed. In one aspect, a list of Walsh functions is maintained in the base station and mobile stations. A Walsh space indicator is transmitted to indicate which of the Walsh functions on the list are to be used in communication. The Walsh space indicator is updated according to the dynamically varying transmit power available or the use of Walsh functions within the base station. Methods by which a mobile station can request Walsh space information are provided. In another aspect, a Walsh space indicator channel is continually broadcast for mobile stations to detect the Walsh space indicator therefrom. In yet another aspect, the Walsh space indicator is used to initialize convolutional encoders and decoders, to provide a mechanism for mitigating against errors introduced while receiving Walsh space indicators. Various other aspects are also presented.

Abstract: In a system including a resource which is shared among a number of users, it is difficult to distribute the available capacity of the resources fairly among the users and still maximize resource utilization. Additionally, it is desirable to allow at least some of the control over usage rates to remain with the users, while at the same time avoiding situations where the resource is overloaded. A system and method are disclosed wherein usage rates are selected from among a set of available rates according to a set of persistence vectors.

Abstract: A preferred roaming list (PRL) carries system and acquisition records for wireless wide area network (WWAN) systems and wireless local area network (WLAN) systems. New system and acquisition records may be defined for WLAN. The PRL and system and acquisition records may be defined to be backward compatible with TIA-683-C. System and acquisition information for WLAN systems may be stored in the new system and acquisition records, respectively. Information used to perform encryption and/or authentication for WLAN systems may be stored in a separate WLAN authentication profile table. The system record for each WLAN system indicates a acquisition record and a profile record for that WLAN system. A network identifier table may also carry system records and profile records for WLAN systems. The system records carry information used for WLAN system selection and acquisition. The profile records carry information used to perform encryption and/or authentication for WLAN systems.

Abstract: An apparatus and method are disclosed for partitioning and downloading executable memory images in low-powered computing devices comprised of multiple processors and a mobile station modem. The general computing subsystem 102 handles tasks generally related to a personal digital assistant (PDA) as well as activating the modem computer subsystem 104 and one or more shared memory modules 108-110. The modem computing subsystem 104 handles tasks associated with a mobile station modem. Power is conserved by not clocking the modem computer system 104 and the shared memory 108-110 during times when modem functions are not needed. The shared memory modules 108-110 are loaded with a binary memory image for use by the modem computer subsystem 104 from a memory 222 under control of the general computing subsystem 102. When needed, the modem computing subsystem 104 is activated to monitor a paging channel, and disabled when it is no longer desired to monitor the paging channel.

Abstract: The standby time of a CDMA cell phone is extended by using two receive chains to monitor the Quick Paging Channel (QPCH) when the signal-to-noise ratio falls within a predetermined range. Monitoring the QPCH saves battery power by obviating the need to monitor the general paging message unless quick paging (PI) bits are set. The QPCH is not monitored, however, in noisy environments where PI bits are incorrectly detected causing the paging message to be needlessly monitored. Power is saved by monitoring the QPCH in noisier environments without increasing the incorrect detection rate. Incorrect detection is reduced in the predetermined range by using an additional receive chain to achieve receive diversity. Although additional power is consumed by the second receive chain in the predetermined range, the power saved by not demodulating the paging message at each slot more than compensates for the additional power consumed by the second receive chain.

Abstract: Frequency estimation information obtained when a wireless communication device (WCD) is in one wireless communication system, such as frequency error or offset information, may be translated to a corresponding frequency error in another system, thereby allowing the WCD to perform a handover to the other system with reduced initial frequency error. As a result, the acquisition time involved in acquiring a signal in the other system may be significantly reduced.

Abstract: Techniques for minimizing dormant reactivations to receive IPv6 Router Advertisements are described. In a first scheme, a timer is used to trigger a wireless terminal to solicit a Router Advertisement. The timer is set to a threshold time period computed based on the current prefix lifetime. When the timer expires, a Router Solicitation is sent. In a second scheme, after the timer expires, a Router Solicitation is sent whenever the terminal is active. In a third scheme, a Router Solicitation is sent when the timer expires if solicitation is triggered and at any time thereafter whenever the terminal is active. In a fourth scheme, two timers are set to two threshold time periods. After the first timer expires, a Router Solicitation is sent whenever the terminal is active. When the second timer expires, a Router Solicitation is sent if solicitation is triggered by a predefined event or condition regardless of the terminals state.

Abstract: This disclosure is directed to techniques for condensed voice buffering, transmission and playback. The techniques may involve identification of encoded voice frames as either speech or a pause, and selective exclusion of a portion of the frames for storage, transmission or playback based on the identification. In this manner, the techniques are capable of condensing a series of encoded voice frames. When variable rate coding is employed, a pause frame may be identified, for example, based on a threshold comparison for the rate of the encoded frame. In some cases, the techniques may involve excluding only a portion of the identified frames from a consecutive sequence of the identified frames, thereby preserving a minimum number of the identified frames needed for intelligible conversation.