Abstract: A wireless terminal using OFDM signaling supporting both terrestrial and satellite base station connectivity operates using conventional access probe signaling in a first mode of operation to establish a timing synchronized wireless link with a terrestrial base station. In a second mode of operation, used to establish a timing synchronized wireless link with a satellite base station, a slightly modified access protocol is employed. The round trip signaling time and timing ambiguity between a wireless terminal and a satellite base station is substantially greater than with a terrestrial base station. The modified access protocol uses coding of access probe signals to uniquely identify a superslot index within a beaconslot. The modified protocol uses multiple access probes with different timing offsets to further resolve timing ambiguity and allows the satellite base station access monitoring interval to remain small in duration.

Abstract: Power control methods and apparatus for use in a sectorized cell of an OFDM communications system are described. Each sector of a cell uses the same frequencies and transmission times and is synchronized with the other sectors in the cell in terms of tone frequencies used at any given time and symbol transmission times. Tones are allocated to channels in each cell in the same manner so that each channel in a sector has a corresponding channel in another sector. Power differences between channels in different sectors are maintained to be within a pre-selected power difference. Different channels in a cell are assigned different power levels. Wireless terminals are assigned to channels based on channel feedback information. Wireless terminals with poor channel conditions are allocated to higher power channels than wireless terminals with good channel conditions. Lower power channels often include more tones per symbol time than high power channels.

Abstract: A wireless terminal determines the position of a moving base station and determines timing and/or frequency corrections. A wireless terminal determines its relative position with respect to the base station and determines a timing adjustment correction. The wireless terminal applies the determined timing correction to control uplink signaling timing and achieve synchronization at the base station's receiver. The wireless terminal determines its relative velocity with respect to the moving base station and determines a Doppler shift adjustment which it adds to the uplink carrier frequency or to its baseband signal. Base station position is determined from the current time and stored information correlating the base station position with time, e.g., for a geo-synchronous satellite. Base station position information, e.g., a GPS derived base station position fix, is determined from downlink airlink broadcast information, e.g., for an aircraft base station.

Abstract: A wireless terminal using OFDM signaling supporting both terrestrial and satellite base station connectivity operates using conventional access probe signaling in a first mode of operation to establish a timing synchronized wireless link with a terrestrial base station. In a second mode of operation, used to establish a timing synchronized wireless link with a satellite base station, a slightly modified access protocol is employed. The round trip signaling time and timing ambiguity between a wireless terminal and a satellite base station is substantially greater than with a terrestrial base station. The modified access protocol uses coding of access probe signals to uniquely identify a superslot index within a beaconslot. The modified protocol uses multiple access probes with different timing offsets to further resolve timing ambiguity and allows the satellite base station access monitoring interval to remain small in duration.

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: Embodiments describe improved coupling of power amplifiers to antennas for the transmission of signals, such as OFDM signals. A large number of separate windings are utilized on a primary side, wherein each winding is for a different OFDM tone. Each OFDM tone may be amplified individually and combined as a results of transformer coupling. For example, the secondary side can have a single winding that combines the different OFDM tones.

Abstract: Base stations transmit strip signals using strip signal segments and self supporting modulation scheme techniques facilitating rapid channel estimate. A strip segment occupies one OFDM symbol time interval and uses a set of downlink tones; some, e.g., half, of the tones are left unused facilitating SIR measurement. The strip segments are advantageously timed to correspond to uplink access intervals in which connected wireless terminals do not typically transmit uplink signals. Connected wireless terminals including: multiple antennas used in combination, an antenna duplex module, single RF receiver chain and single RF transmitter chain, switch antenna coefficient combinations based on strip signal segment timing. The wireless terminal determines an independent downlink channel quality measurement, e.g., SNR and/or SIR for each strip signal segment and for on-going non-strip signaling.

Abstract: Methods and apparatus for providing enhanced audio are described. In some embodiments speech synthesis information is used to provide user control of attributes of received broadcast speech, such as language, tone, speed, gender, and volume. In other embodiments, speech synthesis information is transmitted prior to a broadcast audio signal, allowing the receiving node to substitute synthesized speech for the broadcast audio signal if there is an interruption in the audio signal. Still other implementations allow for the synthesizing of speech that is different than the broadcast audio signal, such as background information, associated local information, title, author, etc. Other embodiments allow for the simultaneous transmission of multiple speech programming in a single transmission stream, allowing the user to select one program from the transmitted set of programs for synthesizing speech representative of the selected program.

Abstract: A wireless communications system, e.g., an OFDM system, uses a plurality of carrier frequencies each with an associated frequency band. A base station sector transmitter in the system transmits ordinary signaling, e.g., user data, in its own assigned band. In addition the sector base station transmitter periodically transmits beacon signals into its own frequency band and the frequency bands used by adjacent sector transmitters for their ordinary signaling. Beacon signals, being short duration high power signals with sector transmission power concentrated on one or a few tones, are easily detectable. Each beacon signal may be identified as to the source base station sector transmitter, e.g., based on tone. A mobile node, tuned to a single carrier band, receives a plurality of beacon signals, identifies the sources of the received beacons, compares the received strength of the beacons, and makes handoff decisions, without having to switch carrier band.

Abstract: Techniques for performing automatic gain control (AGC) at a receiver are described. The receiver may receive an OFDM-based symbol composed of a cyclic prefix and a useful portion. The receiver may scale the OFDM-based symbol with an initial receiver gain, adjust the initial receiver gain based on the cyclic prefix, apply the adjusted receiver gain prior to the useful portion, and process the useful portion to recover at least one signal sent by at least one transmitter. The receiver may select the initial receiver gain, e.g., based on a predicted received power level for the at least one transmitter, a pattern of different receiver gains, etc. The receiver may apply the initial receiver gain at the start of the OFDM-based symbol. The receiver may measure the power of a set of samples in the cyclic prefix and may adjust the receiver gain based on the measured power and a target power.

Abstract: A wireless communications system, e.g., an OFDM system, uses a plurality of carrier frequencies each with an associated frequency band. A base station sector transmitter in the system transmits ordinary signaling, e.g., user data, in its own assigned band. In addition the sector base station transmitter periodically transmits beacon signals into its own frequency band and the frequency bands used by adjacent sector transmitters for their ordinary signaling. Beacon signals, being short duration high power signals with sector transmission power concentrated on one or a few tones, are easily detectable. Each beacon signal may be identified as to the source base station sector transmitter, e.g., based on tone. A mobile node, tuned to a single carrier band, receives a plurality of beacon signals, identifies the sources of the received beacons, compares the received strength of the beacons, and makes handoff decisions, without having to switch carrier band.

Abstract: Transmit and/or receive diversity is achieved using multiple antennas. In some embodiments, a single transmitter chain within a wireless terminal is coupled over time to a plurality of transmit antennas. At any given time, a controllable switching module couples the single transmitter chain to one the plurality of transmit antennas. Over time, the switching module couples the output signals from the single transmitter chain to different transmit antennas. Switching decisions are based upon predetermined information, dwell information, and/or channel condition feedback information. Switching is performed on some dwell and/or channel estimation boundaries. In some OFDM embodiments, each of multiple transmitter chains is coupled respectively to a different transmit antenna. Information to be transmitted is mapped to a plurality of tones. Different subsets of tones are formed for and transmitted through different transmit chain/antenna sets simultaneously.

Abstract: A wireless terminal using OFDM signaling supporting both terrestrial and satellite base station connectivity operates using conventional access probe signaling in a first mode of operation to establish a timing synchronized wireless link with a terrestrial base station. In a second mode of operation, used to establish a timing synchronized wireless link with a satellite base station, a slightly modified access protocol is employed. The round trip signaling time and timing ambiguity between a wireless terminal and a satellite base station is substantially greater than with a terrestrial base station. The modified access protocol uses coding of access probe signals to uniquely identify a superslot index within a beaconslot. The modified protocol uses multiple access probes with different timing offsets to further resolve timing ambiguity and allows the satellite base station access monitoring interval to remain small in duration.

Abstract: Signal detectivity is improved by implementation of address adjustment to reorder samples and to discard undesired samples. Such reordering is utilized when the time order of received samples are distorted and/or corrupted, which can occur in at least three situations. If the samples are distorted in time order, the samples are rearranged to allow the samples to return to proper order. The samples, if corrupted, are discarded and replaced with zero samples.

Abstract: Transmit and/or receive diversity is achieved using multiple antennas. In some embodiments, a single transmitter chain within a wireless terminal is coupled over time to a plurality of transmit antennas. At any given time, a controllable switching module couples the single transmitter chain to one the plurality of transmit antennas. Over time, the switching module couples the output signals from the single transmitter chain to different transmit antennas. Switching decisions are based upon predetermined information, dwell information, and/or channel condition feedback information. Switching is performed on some dwell and/or channel estimation boundaries. In some OFDM embodiments, each of multiple transmitter chains is coupled respectively to a different transmit antenna. Information to be transmitted is mapped to a plurality of tones. Different subsets of tones are formed for and transmitted through different transmit chain/antenna sets simultaneously.

Abstract: A novel composition of weatherable and semi-weatherable materials that can be injection molded or extruded into sheets or rolls to create a roofing product wherein the roofing product overlaps in order to provide a substantially weatherable covering on a roof. The roofing product has a top layer (14) made of weatherable polymers and multiple substrate layers (22, 30) made of semi-weatherable polymers. A decorative, three dimensional appearing layer (16) of colorants is uniquely applied to the bottom surface (15) of the top layer (14). The weatherable top layer (14) is preferably an ASA or acrylic-type copolymer. The semi-weatherable bottom layers (22, 30) are specialized formulations of fire resistant polymers, where the semi-weatherable bottom layers (22, 30) have had the Heat Deflection Temperature (HDT) uniquely improved for use in roofing. The product has multi-layering UV stability. The multiple layers can be injection molded or extruded or laminated or preferably multi-layer-extruded, thus bonded.

Abstract: Apparatus and methods for updating symbol information in a communication device with hardware such as a microcontroller are disclosed. The disclosed apparatus and methods employ waiting for the beginning of a symbol in a sample stream at a predetermined time. One or more programmed instructions are read at the beginning of the symbol, and then symbol information is updated based on the one or more programmable instructions and setting a time for a beginning of a next symbol. The programmed instructions consist of instruction code words that are executed by a dedicated microcontroller or similar hardware, which affords flexibility for updating symbol information, particularly for multimode communication devices operable across multiple communication technologies.

Abstract: A wireless terminal using OFDM signaling supporting both terrestrial and satellite base station connectivity operates using conventional access probe signaling in a first mode of operation to establish a timing synchronized wireless link with a terrestrial base station. In a second mode of operation, used to establish a timing synchronized wireless link with a satellite base station, a slightly modified access protocol is employed. The round trip signaling time and timing ambiguity between a wireless terminal and a satellite base station is substantially greater than with a terrestrial base station. The modified access protocol uses coding of access probe signals to uniquely identify a superslot index within a beaconslot. The modified protocol uses multiple access probes with different timing offsets to further resolve timing ambiguity and allows the satellite base station access monitoring interval to remain small in duration.

Abstract: System and method for providing a timestamp packetized data interface between an RF unit and a modem. According to one embodiment, the RF unit receives an inbound RF signal, processes and demodulates the inbound RF signal to generate samples, generates a timestamp indicative of when the inbound RF signal was received, packetizes and multiplexes the samples and the timestamp, and sends the multiplexed stream to the modem. The modem generates received data from the samples. If the received data type requires a response to be sent at a particular time, the modem generates symbols from responsive outbound data, generates a timestamp which indicates when the outbound data is to be transmitted, packetizes and multiplexes the symbols and the timestamp, and sends the multiplexed stream to the RF unit. The RF unit generates an outbound RF signal from the symbols, and transmits the outbound signal in accordance with the timestamp.

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.