Abstract: Techniques for efficient searching in asynchronous systems, such as W-CDMA, as well as multi-mode searching, are disclosed. In one aspect, step one and step three search are performed in a single search engine. In another aspect, a search engine is configurable to search the offsets of a slot in step one search, producing sequential hypothesis energies, and peak detecting and sorting those energies. In yet another aspect, the peak detector and sorter are configurable to perform step one searching or step three/multimode searching. Various other aspects of the invention are also presented. These aspects have the benefit of circuit area and search-time efficiency which translate into reduced costs, increased standby time, increased acquisition speed, higher quality signal transmission, increased data throughput, decreased power, and improved overall system capacity.

Abstract: Systems and methods for an improved memory allocation service in embedded or wireless devices. Memory is allocated using a combination of container memory items and referencing memory items.

Abstract: An automatic gain controller (AGC) in white space devices is configured with two operational modes. When entering a quiet time of the white space device, the AGC selects the first operational mode. The first operational mode is associated with detecting licensed signals on one or more white space channels by testing a measured received signal strength indicator (RSSI) value to determine which one of a number of the AGC's gain states should be used corresponding to a gain for application to input white space signals on the whitespace channels. When not in the quiet time, the AGC enters a second operational mode. The second operational mode sets a fixed gain state of the AGC's multiple gain states to apply in selecting one of the white space channels on which no licensed signals were detected.

Abstract: Multichannel dynamic frequency selection in wireless networks begins with an access point for a wireless network broadcasting a list of unused channels that are available for communication within the area served by the access point. The various access terminals within this service area receive the broadcast and measure various interference characteristics of each of the channels in the list. The access terminals then send this interference information to the access point, which compiles a matrix of interference information that is associated with the quality of each signal as related to each access terminal. Using this information, the access point selects the appropriate channels to serve the most number of access terminals at the highest possible channel qualities.

Abstract: A method for processing forward link channel signals generated by a CDMA base station includes time sharing by several mobile stations of spreading codes, which are orthogonal codes such as Walsh Code, and code-combining soft/softer handoff across sectors in the mobile station active set to increase dimensions on the CDMA2000 and WCDMA downlink while minimizing intra-sector interference. Since different parts of a packet or frame are transmitted to the user by the different base stations in the active set, earlier decoding and therefore early packet termination is enabled.

Abstract: Synchronization of satellite and terrestrial broadcasts in a shared frequency arrangement is use in order to facilitate simultaneous reception of the broadcasts. A delay value is adjusted based on a synchronization between a first terrestrial broadcast and a satellite broadcast, and a delay value for a second terrestrial broadcast is adjusted based on a synchronization between the second terrestrial broadcast, the first terrestrial broadcast and the satellite broadcast. The adjustment of the relative delay values provides an improved reception pattern based on receipt of a shared frequency communication from multiple sources by improving a signal quality factor within at least selected regions of the coverage areas in which the relative delay values permit synchronization.

Abstract: An apparatus for wireless communications includes a processing system. The processing system is configured to receive an input sound stream of a user, split the input sound stream into a plurality of frames, classify each of the frames as one selected from the group consisting of a non-speech frame and a speech frame, determine a pitch of each of the frames in a subset of the speech frames, and identify a gender of the user from the determined pitch. To determine the pitch, the processing system is configured to filter the speech frames to compute an error signal, compute an autocorrelation of the error signal, find a maximum autocorrelation value, and set the pitch to an index of the maximum autocorrelation value.

Abstract: In a packet communications system stream data is transported over a channel over which packet loss or corruption is possible, with forward error correction (“FEC”) information. A transmitter receives source packets comprising source data, generates FEC source packets formatted to allow for identification of lost or corrupted source packets at a receiver, arranges source data from the source packets into a plurality of source symbols wherein at least one source packet is arranged into more than one source symbol, associates a plurality of source symbols with a source block, generates a plurality of repair symbols from the source block according to a predetermined FEC encoding process and groups the plurality of repair symbols into one or more FEC repair packets associated with the source block. A receiver can use the FEC repair symbols from the FEC repair packets to recover source symbols, as needed.

Abstract: A novel MAC algorithm is disclosed having various features for a modern CDMA interference-shared reverse link, including (a) link quality assurance, (b) individual congestion control, (c) variable data rate transition policy, and/or (d) reverse link partitioning. Link quality assurance is provided by monitoring transmission feedback information (ACK/NACK) to indirectly determine the quality of a communication link. Wireless devices are individually targeted to perform congestion control of the reverse link. Variable data transmission rates and discontinuous transmissions are achieved by individual wireless devices that autonomously adjust their transmission rate and transmit power. The reverse link can also be partitioned among the different wireless devices by individually controlling the transmit power of the wireless devices operating on the reverse link.

Abstract: A method and apparatus are disclosed for forming a frame of interleaved information bits in a communication system, where the decoding of the frame of interleaved information bits may begin before all of the bits in the frame are received. An exemplary interleaved frame is formed by receiving a frame of N information bits within the communication system; encoding the information bits at a code rate R to provide encoded bits; and arranging the encoded bits into a frame of N/R coded bits, wherein a plurality of puncturing patterns pi are applied to the frame of N/R coded bits such that a code rate of R/ai is produced for each of the plurality of puncturing pattern pi. The arrangement of encoded bits involves applying a puncturing pattern pj to the encoded bits; and applying a permutation function to the punctured encoded bits to generate a fractional section of the frame of N/R coded bits. The fractional section of the frame of N/R coded bits comprises N/R*aj bits.

Abstract: Method for segmented message transmission wherein each message is first divided into segments and the segments are fragmented. A segment parameter is applied to each segment, and a segment identifier to each fragment. The fragments are provided to a lower level for preparation into frames for transmission. One embodiment is applied to the transmission of short duration messages, such as control messages. A timer is used to detect an erasure within a plurality of transmission frames, wherein the timer uses an average inter-arrival time period between transmitted frames to determine a missing frame. In one embodiment, the time period is given as ?*AIT, wherein ? is a constant value, and AIT is the average inter-arrival time of frames.

Abstract: A method for wireless communication is disclosed that includes selecting a plurality of probabilities for a symbol based on a bit-to-symbol mapping; calculating a conditional mean of the symbol based on the plurality of probabilities; and, generating a signal representative of the symbol based on the conditional mean of the symbol. An apparatus for performing the method is also disclosed.

Abstract: A method of serving content to multiple clients via a network is provided. Independent sessions with each of a plurality of clients are maintained, wherein the number of clients in the plurality of clients can vary over time, and wherein the start of each session and the end of each session can be independent of the start and end of other sessions. A stream of packet payloads is received, each packet payload of the stream of packet payloads including data generated from the content, wherein each packet payload in at least a subset of the stream of packet payloads includes a different set of data. Each packet payload in the stream of packet payloads is transmitted to each client of the plurality of clients in corresponding packets, wherein the packet payload transmitted to a client at any particular time is independent of the state of the corresponding session.

Abstract: Techniques for managing communications in a cellular network are disclosed. The cellular network can include one or more sectors in which hotspot carriers are deployed. The hotspot carriers can be available to mobile devices beyond sector boundaries defined by the signal strength of ubiquitous carriers. A mobile device can measure a signal strength of a candidate hotspot carrier and estimate a reverse link mobile device transmit power level for communicating on the hotspot carrier. The mobile device may determine whether to add, remove, or maintain the hotspot carrier in its active set based on the estimated transmit power level so as to limit interference to the reverse link of non-hotspot sectors.

Abstract: Methods and apparatus for performing peer to peer communications with access routers and non-access router peer devices are described. An access terminal generates a channel estimate estimating the channel between the access terminal and an access router. For at least some communication with the access router, a channel compensation operation is performed on a symbol to be transmitted prior to its transmission to the access router. In contrast, symbols transmitted to other access terminals are not subject to a channel compensation operation prior to transmission with the receiving access terminal being responsible for implementing a channel compensation operation on the received signal.

Abstract: A communications node can receive a plurality of communication signals, each including a block of data estimates with respective quality metrics. Each block of data estimates can be derived from an original block of data sent over different wireless paths, or from a derived block of data estimates sent over a different wireless path. A data combining circuit can be used to combines the blocks of data estimates as a function of the respective quality metrics to produce an output set of data estimates with a derived quality metric.

Abstract: Techniques for synthesizing a signal having a desired frequency from an oscillation signal. In an aspect, a reference signal having a known frequency may be periodically used to determine a ratio between the desired frequency and the frequency of the oscillation signal. The oscillation signal may be decimated by the ratio to generate a synthesized signal having approximately the desired frequency. In an aspect, the decimation may be performed by generating a pulse in response to the output of an accumulator that accumulates in steps of the ratio. To save power, the oscillation signal may be derived from a low-power oscillator, while the reference signal may be turned on only during periodic calibration. Further aspects for improving the frequency accuracy of the synthesized signal are disclosed.

Abstract: A multicasting system provides congestion control for multicasting using a dynamic layer scheme, where the aggregate sending rates of layers decline over time. Multicast packets are transmitted to layers that are joined by at least one host. A host maintains a reception rate by joining additional layers as the sending rates decline, a host reduces the reception rate by not joining additional layers as fast as the sending rates decline, thus allowing rate reduction even if the sender does not receive leave messages sent from a host.

Abstract: In one embodiment, the present patent application comprises a method and apparatus to generate low rate protographs from high rate protographs, comprising copying a base graph; permuting end points of edges of a same type in copies of the base graph to produce a permuted graph; and pruning systematic input nodes in the permuted graph and the edges connected to them. In another embodiment, the present patent application comprises a method and apparatus to generate high-rate codes from low-rate codes, comprising puncturing a subset of codeword bits, wherein the step of puncturing a subset of codeword bits comprises regular-irregular puncturing the subset of codeword bits, random puncturing variable nodes, or progressive node puncturing variable nodes to obtain a desired code from a preceding code.

Abstract: A method of encoding data into a chain reaction code includes generating a set of input symbols from input data. Subsequently, one or more non-systematic output symbols is generated from the set of input symbols, each of the one or more non-systematic output symbols being selected from an alphabet of non-systematic output symbols, and each non-systematic output symbol generated as a function of one or more of the input symbols. As a result of this encoding process, any subset of the set of input symbols is recoverable from (i) a predetermined number of non-systematic output symbols, or (ii) a combination of (a) input symbols which are not included in the subset of input symbols that are to be recovered, and (b) one or more of the non-systematic output symbols.