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: Wireless devices, e.g., in a cognitive radio network, discover and use locally available usable spectrum for communication. Beacon signaling facilitates available spectrum discovery and spectrum usage coordination. A wireless terminal, which may have entered a new area and powered up, monitors to detect for the presence of beacon signals in a first communications band. The wireless terminal makes a decision as to whether or not to transmit based on the monitoring result. In addition, when beacon signals are detected, decoded information recovered by the wireless terminal from the received beacon signals is used in making the transmission decision. The decoded information includes, e.g., type information indicating that a second band is allowed to be used for peer-peer communications and/or identification information identifying at least one of a wireless communications device which transmitted the beacon signal and a current user of the wireless communications device which transmitted the beacon signal.

Abstract: Disclosed are embodiments of a dental prophylaxis angle. One dental prophylaxis angle includes a body having a neck that defines a first axial bore and a head that defines a second axial bore, the first and second axial bores communicating at an intersection and being angularly-offset from each other, a drive gear rotatably mounted in the first axial bore and having a drive gear head and a locking flange axially-offset from the drive gear head, an annular locking groove being defined between the drive gear head and the locking flange, a driven gear rotatably mounted in the second axial bore and operatively coupled to the drive gear, and a gear retainer having an annular body configured to extend about an outer surface of the head, a heel extending from the annular body, an arm extending from the heel, and a wedge extending from the arm.

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: 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: A device includes a zero symbol rate (ZSR) coding/modulation module and a second type coding/modulation module. Both modules generate modulation symbols to be conveyed using the same air link resources but with the non-zero ZSR symbols having a higher power level. The ZSR module generates a mixture of zero and non-zero modulation symbols. A ZSR modulation scheme communicates information using both the position of the non-zero modulation symbols and the phase and/or amplitude of the non-zero modulation symbols. Different ZSR schemes, implementing different ratios relating the number of zero symbols to the total number of symbols, can be associated with different low data rates while second module modulation schemes can be associated with different high data rates. Modulation symbols from two modules are in some embodiments, superimposed. In some embodiments, non-zero ZSR modulation symbols punch out second module modulation symbols which occupy the same air link resource.

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 signal 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: Systems and methodologies are described that facilitate sharing bandwidth between a wide area network and a local area peer-to-peer network. The peer-to-peer network may use an air interface technology that is similar to distinct from an air interface technology used in the wide area network. Moreover, the wide area network and the local area peer-to-peer network may utilize distinct sets of parameters. For example, if the wide area network and the peer-to-peer network use OFDM-based air interface technologies, parameters such as tone spacing, symbol time, cyclic prefix, and the like of the two networks may vary. Further, peer-to-peer parameters may be a function of parameters for the wide area network.

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: 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: Downlink traffic channel data rate options and methods of indicating to a wireless terminal a utilized downlink data rate option are described. The downlink traffic channel rate option for a segment is conveyed using an assignment signal and/or a block in the downlink traffic channel segment which is not used for user data. Downlink segment assignment signals in some implementations allocate fewer bits for rate option indication than are required to uniquely identify each option. In some implementations low rate options, e.g., using QPSK, are uniquely identified via assignment signals. Higher rate options, e.g., using QAM16 modulation, are conveyed via the distinct information block in the downlink traffic segment using a first coding/modulation method. Still higher rate options, e.g., using QAM16, QAM64, or QAM256, are conveyed via the information block in the segment using a second coding/modulation method which is applied to the rate option information.

Abstract: The claimed subject matter relates to providing uplink data rate option information in an uplink traffic channel segment. A wireless terminal may indicate a data rate option being used for the segment via an energy pattern applied to the tone-symbols of the segment. To indicate a first data rate option, additional energy may be applied to a first set of tone-symbols of the segment. To indicate a second rate option, additional energy may be applied to a second set of tone-symbols of the segment, the second set being different from the first set. According to some aspects, each implemented energy pattern may be represented by a pattern, which has a slope (e.g., in a logical, pre-hopped representation of the channel segment), where some of the patterns have positive slope and some of the patterns have negative slope.

Abstract: A wireless terminal receives an uplink traffic channel segment assignment including a maximum uplink rate option indicator. Each uplink rate option corresponds to a number of information bits, coding rate and modulation method. The maximum rate option indicator indicates the highest rate option that the wireless terminal is permitted to use when transmitting in the assigned traffic channel segment from the perspective of the base station. In some embodiments, the wireless terminal uses interference measurements to further quality, e.g., conditionally reduce, the maximum uplink rate option that may be used. Then, the wireless terminal selects an uplink rate option to use which is less than the determined allowed maximum uplink rate option, e.g., based on the amount of user data to communicate. The wireless terminal transmits data in the assigned uplink traffic channel segment in accordance with the wireless terminal selected uplink rate.

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: 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: A method, apparatus, and machine readable medium for processing a plurality of Z-vectors. Each Z-vector includes Z elements, and each element includes K bits. The Z-vectors correspond to a binary codeword, portions of which have a relationship to a plurality of transmission units. The Z-vectors are stored in a set of D memory arrays. Each memory array includes Z rows of memory locations. Each memory location corresponds to a different array column, and each array column corresponds to a different Z-vector. Each Z-vector identifies one column. A series of sets of control information is generated. Each set includes a transmission unit identifier, a Z-vector identifier, and a row identifier. For at least one set, P times K divided by D bits is read from each column identified by the Z-vector that is identified by the Z-vector identifier included in the set.

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: An iterative message passing decoder, e.g., an LDPC decoder, operating in conjunction with a soft input-soft output signal processing unit, e.g., an ISI detector, has an error floor performance region influenced by the decoder's sub-optimal message passing nature. Error floor reduction is achieved by a simple message re-initialization mechanism. Decoder edge states, e.g., constraint to variable node messages in decoder memory, are reinitialized, e.g., for an iteration, during the decoding after soft values provided by signal processing unit have improved. During the message re-initialization and for some subsequent amount of iterative decoder processing, extrinsic information fed back from the decoder to the signal processing unit and/or soft values delivered to the decoder from the signal processing unit, in an outer communications loop, is temporarily frozen, e.g., using a switch and a buffer. Then, the outer communications loop is restored as the decoding continues, achieving improved decoding performance.

Abstract: A base station selects and assigns uplink segments to specific wireless terminals. The base station estimates potential system interference levels, selects, assigns, and transmits a maximum uplink rate indicator value to a wireless terminal indicating the maximum uplink data rate that the wireless terminal is permitted to use. The wireless terminal receives the maximum data rate indicator and selects an uplink data rate to use which is less than or equal to the maximum data rate indicator level. The selection includes consideration of data amounts, data importance, communications channel quality, changes affecting the channel and/or power information. The wireless terminal encodes information indicative of the selected used rate with the user data/information to be transmitted by placing additional energy on a subset of the uplink signals. The base station receives the uplink signals including user data/information and data rate.

Abstract: Methods and apparatus of the present invention are used to implement a communications system wherein different devices using the same LDPC code are 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 is implemented as a controllable multi-stage switching device 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.