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: Methods and apparatus supporting efficient paging in a wireless communications system supporting both access node based communications and peer to peer communications are described. Paging timing intervals are set aside in the timing structure such that multi-mode wireless terminals can monitor, e.g., in an infrastructure band, for pages from a base station whether the wireless terminal is operating in a base station attachment point mode or is operating in a peer to peer communications mode. Wireless terminals operating in a peer to peer mode, e.g., using a non-infrastructure band, suspends peer to peer communications during the paging intervals. The time periods, in which the wireless terminal checks pages are, in some embodiments, predetermined, so that both the wireless terminal and base station are synchronized on when a page should be delivered. This synchronization helps reduce the wastage of session time in the peer to peer sessions.

Abstract: A first mobile node supports peer to peer communications but not cellular communications. Other mobile modes in the communication system support a cellular mode and may support a peer to peer communications mode. The communications system is such that spectrum may be dynamically reallocated between being designated to be used for peer to peer operations and being used primarily for cellular network based operations. Beacon signals are used to communicate a current mode of frequency spectrum usage designation. The first mobile node, being in an ongoing peer to peer communications session detects that the spectrum is being reallocated for cellular based operations. The first mobile node reduces its transmission power level in response to the detected spectrum reallocation. In some embodiments, the first mobile is allowed to continue its ongoing peer to peer session while the spectrum is primarily allocated for cellular communications, albeit at a lower transmission power level.

Abstract: A wireless terminal determines a desired mode of base station operation with regard to whether the base station is to function as a network access node or is to function in a peer to peer mode with regard to a frequency band, and communicates a change signal to the base station. Some change signals are request signals requesting a base station to dynamically reallocate spectrum usage, while other change signals are command signals ordering the base station to reallocate spectrum usage. Information indicating a level of authority corresponding to the change signals, in some embodiments, corresponds to one of a device identifier, a user identifier, and a priority level indicator. An exemplary command signal comes from a device used by a government agent with the authority to override spectrum usage.

Abstract: Wireless terminal operation is coordinated to be responsive to dynamic communications frequency spectrum reallocation between infrastructure based communications usage and peer to peer communications usage. Methods and apparatus in which mobile nodes switch between cellular and peer to peer communication modes of operation are described. Broadcast signals, e.g., beacon signals, are monitored and detected by the mobile node to ascertain a current spectrum usage designation, and the mobile node switches operational modes in response to detected changes in the broadcast signals.

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 composite signal includes a high power beacon signal and low power corresponding wideband synchronization signal and is communicated over a time interval exceeding a single OFDM transmission time interval. A base station transmits one or more different such composite broadcast signals in a recurring timing structure. Each different potential beacon signal, e.g., a single tone signal, is paired with a unique wideband synchronization signal. A wideband synchronization signal includes at least some predetermined null tones and at least some predetermined non-null tones. For a given wideband synchronization signal, the predetermined null tones carry predetermined modulation symbol values, A wireless terminal receives a composite signal, identifies a beacon, determines a corresponding known wideband synchronization signal, compares received to known wideband synchronization signals, and determines at least one of a timing adjustment, frequency adjustment and channel estimation.

Abstract: Methods and apparatus for allocating tones for communications in the strip-symbol periods in an OFDM system are described. In a strip-symbol, the signal is transmitted using the tones in a tone subset, which is selected from a predetermined set of tone subsets according to a fixed schedule sequence. Adjacent base stations and sectors use the same set of tone subsets but different schedule sequence to minimize the number of collisions between the tone subsets used in adjacent sectors and neighboring cells.

Abstract: Methods and apparatus for communication over a block-coherent communication system are described. The present invention is directed to methods of interleaving coded bits that are encoded by codes, e.g., LDPC codes, having graph structures largely comprised, e.g., of multiple identical copies of a much smaller graph.

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: Methods and apparatus for scaling soft values as part of an error correction decoding process are described. Accurate decoding depends on use of the appropriate scale factor. Selection and use of the scale factor to scale soft values is designed to improve and/or optimize decoder performance without the need for prior knowledge of the correct scale factor or the actual channel conditions at the time the signal from which the soft values were obtained was transmitted through a communications channel. The techniques of the present invention assume that the soft values to be processed were transmitted through a communications channel having a quality that can be accurately described by a channel quality value. A scale factor is determined from the distribution of soft values to be scaled and an assumption that the channel through which they were transmitted was of the quality corresponding to a preselected channel quality value.

Abstract: Wireless terminals receive beacon signals from other communication devices and make transmission decisions based on priority information communicated by the beacon signals. Priority information communicated in a beacon signal includes, e.g., one of device priority, user priority and session priority. A wireless terminal compares priority information recovered from received beacon signals with its own current level of priority. A transmission decision based on received priority information includes deciding not to transmit user data when received priority information indicates a higher priority than its own priority level. Another transmission decision based on received priority information includes deciding to transmit user data when the received priority information indicates a lower priority than its own priority level.

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: 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 use din 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: Wireless devices, e.g., in a cognitive radio network, discover and use locally available usable spectrum for communication. Beacon signaling facilitates available spectrum discovery, spectrum usage coordination, and device identification. A wireless terminal, which may have entered a new area and powered up, monitors to detect for the presence of beacon signals in a communications band. When the wireless terminal fails to detect a beacon, the wireless terminal assumes that the spectrum is available and transmits its user beacon signal thereby providing notification of its presence in the area to other wireless terminals. The wireless terminal maintains a coordinated timing relationship between its beacon transmit interval and beacon detect interval, which are performed on an ongoing basis. The combination of beacon TX interval and beacon monitoring interval represents a small fraction of total time, allowing for power conservation.

Abstract: A base station generates and transmits a multi-symbol beacon/timing synchronization signal. The multi-symbol beacon/timing synchronization signal includes: (i) an initial symbol including a body portion and a cyclic prefix, the cyclic prefix preceding the body portion and being generated from an end portion of the body portion and (ii) an extension symbol, which immediately follows the initial symbol. The extension symbol includes a first copy of the body portion beginning at the start of the extension symbol. The first copy of the body portion is immediately followed by a truncated portion, which is a copy of an initial portion of the body portion. The multi-symbol beacon/timing synchronization signal includes a single high power beacon tone, a plurality of low power tones comprising the synchronization signal, and a plurality of intentional Null tones. Each tone designation remains the same for both the initial symbol and the extension symbol.

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: In a first mode of dedicated control channel (DCCH) operation, a wireless terminal is allocated more segments than in a second mode. The wireless terminal uses different information bit to modulation symbol mapping in the different modes. On a per DCCH segment basis, the same number of modulation symbols are communicated in either mode but more information bits are conveyed in the second mode. Information bits for a DCCH segment are partitioned into two subsets. The two subsets are used to generate another set, each of the two subsets and the another set are input to the same mapping function to generate three equal size sets of modulation symbols which are transmitted via the DCCH segment. Uplink tone hopping is used such that one of the equal size sets of modulation symbols for the DCCH segment uses the same tone but a different set uses a different tone.

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.