Abstract: In a cellular wireless system with interference originating from other base stations, a system for reducing the interference comprises: a. in the SS, means for canceling the signals of one or more of k BSs; b. at each BS, repeatedly sending the same data k+1 times, coded with a biphase code and synchronized in time, to allow to constructively combine the transmissions from a desired BS while destructively combining the transmissions from the other BSs. A method for transmitting signals from a first base station (BS) to a subscriber station (SS), while reducing interference from adjacent BSs, comprising: A. Allowing no change over time, assuming the transfer function for relevant channels does not change; B. Keeping constant the data transmitted from relevant BSs, or transmitting the opposite/negative signals; C. Finding the data of each BS, by combining received signals.

Abstract: A a system for allocating subcarriers to subscribers, comprising a subcarriers allocation controller, connected to a subcarrier modulation unit in a transmitter and to a subcarrier demodulation unit in a receiver for setting a group of subcarriers to be used therein. The transmitter and the receiver are part of the transceiver and subcarriers allocation is made according to a Reed-Solomon code. In a multicarrier system, a method for allocating subcarriers to subscribers, comprising: A. keep a table of R-S codes for frequency group allocation to base stations; B. assign one set of subcarriers based on R-S codes to a base station; C. assign other sets of subcarriers based on R-S codes to other base stations in such a way that adjacent base stations have different R-S codes.

Abstract: A system for allocating subcarriers to subscribers, comprising a subcarriers allocation controller, connected to a subcarrier modulation unit in a transmitter and to a subcarrier demodulation unit in a receiver for setting a group of subcarriers to be used therein. The transmitter and the receiver are part of the transceiver and subcarriers allocation is made according to a Reed-Solomon code. In a multicarrier system, a method for allocating subcarriers to subscribers, comprising the steps of: A. keep a table of R-S codes for frequency group allocation to base stations; B. assign one set of subcarriers based on R-S codes to a base station; C. assign other sets of subcarriers based on R-S codes to other base stations in such a way that adjacent base stations have different R-S codes, to minimize the number of collision points therebetween.

Abstract: In a unidirectional or broadcasting communication system using OFDM transmission from a base station to subscriber units, a device for achieving a bi-directional channel comprising: A. a transmitter in the subscriber units for transmitting signals that are orthogonal to signals transmitted from the base station and are also orthogonal to signals from other subscriber units; B. a receiver in the base station for receiving and processing together signals from a plurality of subscriber units; C. a controller for allocating to each subscriber unit several carriers that are separated from each other (not adjacent to each other).

Abstract: A communication system using OFDM transmission from a base station to subscriber units, includes means for achieving a bi-directional channel. These means comprise transmitting means in the subscriber units for the transmission of signal synchronous with the guard time interval in the OFDM transmission, and receiving means in the base station for the reception of the transmitted signals. The system also includes signal shaping means in the receiver of the base station and/or the subscriber unit for the application of a window in time to signals received therein. A communication system includes a combination of CDMA modulation codes and OFDM coding/decoding means to achieve orthogonality between signals from the various users in the uplink. A communication system includes a combination of OFDM and channeling means for achieving orthogonality between signals from the various users in the uplink.

Abstract: A cellular wireless system using a single frequency OFDMA channel. Base stations include means for synchronization in frequency and time for control purposes. The synchronization means include same Frame numbers and slot index and same reference clock. In a cellular wireless system using a single frequency OFDMA channel, wherein base stations include means for synchronization in frequency and time for control purposes, a method for organizing data and pilots into sub-channels comprising pilots allocations among BSs. The method may further include taking the variable pilots and performing the allocation while shifting through time.

Abstract: A a system for allocating subcarriers to subscribers, comprising a subcarriers allocation controller, connected to a subcarrier modulation unit in a transmitter and to a subcarrier demodulation unit in a receiver for setting a group of subcarriers to be used therein. The transmitter and the receiver are part of the transceiver and subcarriers allocation is made according to a Reed-Solomon code. In a multicarrier system, a method for allocating subcarriers to subscribers, comprising: A. keep a table of R-S codes for frequency group allocation to base stations; B. assign one set of subcarriers based on R-S codes to a base station; C. assign other sets of subcarriers based on R-S codes to other base stations in such a way that adjacent base stations have different R-S codes.

Abstract: In an OFDM-based receiver, a time synchronization unit comprising: A. a device for extracting pilot signals contained in the OFDM received signal; B. a device for analyzing pilot signals in the frequency domain and for issuing a signal indicative of a synchronization error in the received signal; C. a device for correcting the synchronization error, responsive to the signal indicative of the synchronization error. In an OFDM-based receiver, an automatic frequency correction device in a subscriber unit comprising: A. an inner frequency correction loop for generating a LO frequency related to a frequency of a received signal; B. an outer frequency correction loop for correcting the LO frequency according to instructions received from a base station.

Abstract: In an OFDM-based receiver, means for achieving time synchronization comprising: A. means for extracting pilot signals contained in the OFDM received signal; B. means for analyzing the pilot signals in the frequency domain and for issuing a signal indicative of a synchronization error in the received signal; C. means for correcting the synchronization error responsive to the signal indicative of the synchronization error. In an OFDM-based receiver, automatic frequency correction means in a subscriber unit comprising: A. an inner frequency correction loop for generating a LO frequency related to a frequency of a received signal; B. an outer frequency correction loop for correcting the LO frequency according to instructions received from a base station. In an OFDM-based receiver, a channel sounder comprising: A. means for extracting pilot signals contained in the OFDM received signal; B.

Abstract: In a system packing multiple PDUs on a single physical burst and using OFDM or OFDMA, a synchronization method comprising: a. performing an initial lock; b. processing each new header information, verifying if checksum OK, and if OK—remain in (b), system is in locked state; c. activating new header seeker, to enable running window processor to compare the expected checksum with the last byte as tentative checksum; d. declaring Tentative lock, when detecting a checksum correspondence; e. declaring Final lock, when two or more consecutive successful detections of headers, at their expected locations based on prior detections, then Goto (b).

Abstract: An apparatus and method for the analysis of a captured interaction associated with a traveler and an agent, the apparatus comprising an at least one first station for capturing an at least one first interaction along a traveler path, an at least one second station for capturing an at least one second interaction along the traveler path and an analysis device for comparing the at least one second interaction with the at least one first interaction.

Abstract: A communication system using OFDM transmission from a base station to subscriber units, includes means for achieving a bi-directional channel. These means comprise transmitting means in the subscriber units for the transmission of signal synchronous with the guard time interval in the OFDM transmission, and receiving means in the base station for the reception of the transmitted signals. The system also includes signal shaping means in the receiver of the base station and/or the subscriber unit for the application of a window in time to signals received therein. A communication system includes a combination of CDMA modulation codes and OFDM coding/decoding means to achieve orthogonality between signals from the various users in the uplink. A communication system includes a combination of OFDM and channeling means for achieving orthogonality between signals from the various users in the uplink.

Abstract: A Cellular network system wherein the physical layer as defined in 802.16a includes means for its optimization for mobile operators for improved reliability, coverage, capacity, user location, fully scalability, and mobility from 2-6 Ghz, while working in a reuse of 1. The same RF frequency is allocated to all sectors in the cell. The system further includes means for its operation in a Coordinated Synchronous mode, wherein permutations, collisions and averaging interferences from other cells cause limitations on the use of high QAM modulations, which sometimes can increase capacity up to three times (64 QAM instead QPSK).

Abstract: A soft handoff system for a wideband wireless cellular network, comprises diversity reception enhancement means, channel equalization for coherent processing means and coherent summing means. The downlink system further includes means for implementing diversity, allowing two base stations to concurrently transmit the same information, with coherent summing at the mobile receiver. A soft handoff method for a wideband wireless cellular network, comprises: 1) The mobile subscriber continuously evaluates the quality of the channel; When it deteriorates, the mobile requests a handoff; 2) the base station activates diversity transmissions from one or more additional base stations, which transmit the same messages/packets to the mobile; The subcarriers allocation is transmitted to the mobile; 3) the mobile adds coherently the receptions from two or more base stations, for improved SNR.

Abstract: A Bi-directional wireless telecommunication system includes a pair of transceivers each including a transmitter having a transmit delay DT, and a receiver having a receive delay DR wherein compacted concatenated FEC coding is achieved, and having an overall one-way transmission delay including a transmit delay DT and a receive delay DR of less than about 10 ms.