Abstract: A flexible and relatively hardware efficient LDPC decoder is described. The decoder can be implemented with a level of parallelism which is less than the full parallelism of the code structure used to control the decoding process. Each command of a relatively simple control code used to describe the code structure can be stored and executed multiple times to complete the decoding of a codeword. Different codeword lengths are supported using the same set of control code instructions but with the code being implemented a different number of times depending on the codeword length. The decoder can switch between decoding codewords of different lengths, without the need to change the stored code description information, by simply changing a code lifting factor that is indicative of codeword length and is used to control the decoding process. When decoding codewords shorter than the maximum supported codeword length some block storage locations may go unused.

Abstract: Methods and apparatus supporting peer to peer communications are discussed. A base station, serving as an access node for wireless terminals also communicates information supporting peer to peer communications. A base station transmits a beacon signal conveying information about a peer to peer frequency band and also receives user data from a plurality of wireless terminals, using the base station as a current point of network attachment. In some embodiments, the beacon signal is transmitted into the same frequency band being used for access node based communications and identifies a different frequency band which is to be used as a peer to peer frequency band. Alternatively, or in addition, in support of peer to peer communications, a beacon signal transmission apparatus, a free standing device which doesn't transmit user data, transmits a sequence of beacon signal bursts, each beacon signal burst including at least one high power beacon symbol.

Abstract: In modern iterative coding systems such as LDPC decoder and turbo-convolutional decoder in which the invention may be used, the core computations can often be reduced to a sequence of additions and subtractions alternating between logarithm and linear domains A computationally efficient and robust approximation method for log and exp functions is described which involves using a simple bit mapping between fixed point fractional data format and floating point format. The method avoids costly lookup tables and complex computations and further reduces the core processing to a sequence of additions and subtractions using alternating fixed point and floating point processing units.

Abstract: A system is provided for tracking an asset within a geographic area. The system includes an antenna mast supportable by, and extending upward from, an object configured to move or facilitate movement of the asset. The antenna mast is capable of supporting a plurality of wireless locating units of a plurality of geo-spatial positioning systems, which are configured to locate a respective one or more locating units, and thereby the asset, within the geographic area. The system also includes a controller positionable on the object and configured to control operation of the wireless locating units. The controller is further configured to direct transmission of data to a host via one of the locating units or another wireless transmitter, and in a manner that accounts for a wireless link between the respective locating unit or other wireless transmitter and the host.

Abstract: The claimed subject matter relates to encoding and decoding information in a wireless communication system using soft-demodulation and interleaving of concatenated code received in a strip channel. A set of symbols is received containing a plurality of information bits, dividing the received set of symbols into a plurality of subsets of symbols, each subset corresponding to the input of an inner code demodulation selecting a set of initial a priori values of the inner code demodulation for each subset of symbols, and demodulating each subset of symbols, using the initial a priori values of the subset of symbols and an inner code generator matrix, to generate a plurality of first soft information values as the output of the inner code demodulation.

Abstract: Data communication over a block-coherent channel in a communication system is described. Low-complexity demodulation techniques that allow good performance are described. A dwell, e.g., a set of block coherent symbols transmitted including a known symbol, e.g., a pseudo pilot symbol, are received, demodulated and decoded by a joint decoder/demodulator employing soft inputs, soft outputs, and interleaving of messages. Low-complexity SISO demodulator is suitable for processing pseudo-pilot modulated information corresponding to each of one or more dwells. The low-complexity method achieves good performance when turbo equalization is used. Some decoding and demodulation embodiments include independent phase estimates and updated independent phase estimates following the extrinsic principle to generate soft symbol values and soft bits.

Abstract: A location system for tracking assets within a terminal includes a Differential Global Positioning System (DGPS) reference receiver within the terminal that receives GPS signals and generates DGPS correction data. In one aspect, a roving receiver unit is carried by an asset to be tracked within the terminal. It includes a GPS receiver that receives GPS signals and the DGPS correction data from the DGPS reference receiver. A tag transmitter transmits a wireless RF signal containing GPS location data based on received GPS signals and DGPS correction data. At least one access point is positioned within the terminal for receiving the wireless RF signal from the tag transmitter. A processor is operatively connected to the at least one access point for receiving GPS location data and determining a location of the asset to be tracked.

Abstract: Methods and apparatus for implementing and/or using amplifiers and performing various amplification related operations are described. The methods are well suited for use with, but not limited to, switching type amplifiers. The methods and apparatus described herein allow for the use of switching amplifiers while reducing and/or compensating for distortions that the use of such amplifiers would normally create. The described methods and apparatus can be used alone or in combination with various novel signaling schemes which can make it easier to compensate for the non-ideal behavior of switching amplifiers in such a way as to enable practical application in wireless transmission and/or other applications.

Abstract: A flexible and relatively hardware efficient LDPC encoder is described. The encoder can be implemented with a level of parallelism which is less than the full parallelism of the code structure used to control the encoding process. Each command of a relatively simple microcode used to describe the code structure can be stored and executed multiple times to complete the encoding of a codeword. Different codeword lengths can be supported using the same set of microcode instructions but with the code being implemented a different number of times depending on the lifting factor selected to be used. The LDPC encoder can switch between encoding codewords of different lengths, without the need to change the stored code description information, by simply changing a code lifting factor used to control the encoding processes. When coding codewords shorter than the maximum supported codeword length some block storage locations and/or registers may go unused.

Abstract: A flexible and relatively hardware efficient LDPC decoder is described. The decoder can be implemented with a level of parallelism which is less than the full parallelism of the code structure used to control the decoding process. Each command of a relatively simple control code used to describe the code structure can be stored and executed multiple times to complete the decoding of a codeword. Different codeword lengths are supported using the same set of control code instructions but with the code being implemented a different number of times depending on the codeword length. The decoder can switch between decoding codewords of different lengths, without the need to change the stored code description information, by simply changing a code lifting factor that is indicative of codeword length and is used to control the decoding process. When decoding codewords shorter than the maximum supported codeword length some block storage locations may go unused.

Abstract: Methods and apparatus for implementing a multi-carrier communications system are described. Various approaches to a phased system deployment and system configurations resulting from different levels of deployment are described. In addition mobile node and methods of operating mobile nodes in communications systems that may have different levels of deployment in different cells are described.

Abstract: Methods and apparatus for implementing memory efficient LDPC decodes are described. In accordance with the invention message information is stored in a compressed state for check node processing operations. The state for a check node is fully updated and then subject to an extraction process to generate check node to variable node messages. The signs of messages received from variable nodes may be stored by the check node processor module of the invention for use in message extraction. The check node processor can process messages in variable node order thereby allowing the variable node processor and check node processor to operate on messages in the same order reducing or eliminating the need to buffer and/or reorder messages passed between check nodes and variable nodes. Graph structures which allow check node processing on one graph iteration to proceed before the previous graph iteration has been completed are also described.

Abstract: Systems and methodologies are described that facilitate detecting and/or identifying peers in a local area peer-to-peer network. Times (e.g., peer discovery intervals) for performance of mutual detection and identification between peers may be synchronized (e.g., based upon a signal broadcast to the peers), Further, within each partitioned peer discovery interval, a wireless terminal may select a portion of time to transmit (e.g., broadcast) short messages that may be employed by peers to detect and/identify the wireless terminal. Moreover, the remainder of the time within the partitioned peer discovery interval may be employed to listen to short messages received from peers.

Abstract: A flexible and relatively hardware efficient LDPC encoder is described. The encoder can be implemented with a level of parallelism which is less than the full parallelism of the code structure used to control the encoding process. Each command of a relatively simple microcode used to describe the code structure can be stored and executed multiple times to complete the encoding of a codeword. Different codeword lengths can be supported using the same set of microcode instructions but with the code being implemented a different number of times depending on the lifting factor selected to be used. The LDPC encoder can switch between encoding codewords of different lengths, without the need to change the stored code description information, by simply changing a code lifting factor used to control the encoding processes. When coding codewords shorter than the maximum supported codeword length some block storage locations and/or registers may go unused.

Abstract: Peer to peer communication timing, e.g., for an ad hoc network, is referenced with respect to an external broadcast signal from a terrestrial or satellite based transmitter. Wireless terminals, seeking to communicate via peer to peer communications, receive the reference broadcast signal, and set their internal timing structure with respect to the reference signal. This facilitates peer to peer timing coordination. A wireless terminal transmits a signal, e.g., a user beacon signal identifying its presence, during a time interval during which another wireless terminal is expected to be monitoring. Reference signal based coordinated timing and use of user beacon signals allows the wireless terminals to maintain situational awareness and coordinate peer to peer communications, while keeping power consumption low, since wireless terminal modules can be powered down during predetermined intervals in the coordinated timing structure where the wireless terminal does not need to transmit and/or receive.

Abstract: Systems and methodologies are described that facilitate encoding and/or decoding signals utilized to identify a wireless terminal during peer discovery interval(s). Substantially any type of function that constrains encoding and/or decoding within a peer-to-peer network may be utilized. For example, a reversible function may be employed that enables a receiving peer to discern an identifier of a transmitting peer over a series of peer discovery intervals. Pursuant to another example, an irreversible function may be utilized whereby a receiving peer may be unable to decipher the identifier of the transmitting peer from a received signal, however, expected signal formats of buddy peers may be compared to the received signal to determine a presence of one of the buddy peers in a vicinity.

Abstract: A wireless terminal supports both peer to peer communications and access node based communications. The wireless terminal considers and evaluates communications link alternatives and selects between (i) communication using a peer to peer link and (ii) communications using a link, with a base station serving as an access node, Received signals corresponding to each of the link alternatives are used in performing link quality determinations. In one example, a received user beacon sisal :from a peer wireless terminal is the received signal used for the peer to peer link evaluation and a: base station beacon signal is the received signal used for the access node link evaluation. A link is selected as a function of quality determination, predicted data throughput, link maintenance energy requirements, and/or least cost routing determination information.

Abstract: Methods and apparatus of the present invention can be used to implement a communications system wherein different devices using the same LDPC code can be implemented using different levels of parallelism. The use of a novel class of LDPC codes makes such differences in parallelism possible. Use of a factorable permuter in various embodiments of the invention make LDPC devices with different levels of parallelism in the encoder and decoder relatively easy to implement when using the codes in the class of LDPC codes discussed herein. The factorable permuter may be implemented as a controllable multi-stage switching devices which performs none, one, or multiple sequential reordering operations on a Z element vector passed between memory and a Z element vector processor, with the switching one individual vectors being controlled in accordance with the graph structure of the code being implemented.

Abstract: Methods and apparatus related to assignment in a wireless communications system are described. A mobile is assigned an identifier and a mask value, e.g., as part of a state transition message. The mobile uses the assigned identifier and/or the assigned mask value in determining whether assignments included in assignment messages, e.g., traffic channel assignment messages, are directed to the wireless terminal. Predetermined associations between assignment slots, assigned segments, and/or mask values are utilized to limit control signaling overhead. Different groups of segments are available for assignment to different wireless terminals as a function of mask values. Different types of assignment messages use different amounts of information bits to convey the assignment. Some types of assignments use a wireless terminal identifier, while other types of assignments use a wireless terminal identifier and a mask identifier. The mask identifier, e.g.

Abstract: The claimed subject matter relates to enabling antenna switching in a wireless terminal that has multiple receive antennas per receive chain via soft-demodulation and interleaving of concatenated code received in a strip channel. A coherent demodulation protocol may be performed to estimate an SNR for a first antenna during a first time period, and a non-coherent demodulation protocol may be utilized on the strip channel to estimate an SNR for at least one other antenna during a second time period. SNRs may be compared and the terminal may select the antenna with the highest SNR for a next transmission superslot.