Abstract: A method for efficiently scheduling virtual resource blocks to physical resource blocks is disclosed. In a wireless mobile communication system, for distributed mapping of consecutively allocated virtual resource blocks to physical resource blocks, when nulls are inserted into a block interleaver used for the mapping, they are uniformly distributed to ND divided groups of the block interleaver, which are equal in number to the number (ND) of physical resource blocks to which one virtual resource block is mapped.

Abstract: A method for efficiently scheduling virtual resource blocks to physical resource blocks is disclosed. In a wireless mobile communication system that supports a resource block group (RBG) allocation scheme, for distributed mapping of consecutively allocated virtual resource blocks to physical resource blocks, there is proposed a mapping method capable of increasing the number of distributed virtual resource blocks to a maximum while satisfying gap limitations, when the length of the physical resource blocks is different from the length of the distributed virtual resource blocks. Also, the number of distributed virtual resource blocks and the structure of an interleaver are limited for efficient scheduling.

Abstract: A correlation canceller modulates a communication signal over a plurality of channels and an epoch aperture by a plurality of interference response signals corresponding to linear response by one or more filtering effects to generate an inversely correlated communication signal.

Abstract: A circuit for generating a cyclic prefix of a symbol comprised of a sequence of time samples, the prefix being the reproduction of the last samples of the symbol at the beginning of the symbol, the symbol being obtained by inverse Fourier transform of complex coefficients corresponding to respective frequencies. The circuit includes a multiplier that shifts the phase of each complex coefficient by a value proportional to its frequency, a memory for storing the samples at the beginning of the symbol, and a multiplexer that copies at the end of the symbol the stored samples.

Abstract: An IS-OFDM system for point-to-point wireless communications that suppresses narrow-band interference comprises an IS-OFDM transmitter and an IS-OFDM receiver, wherein a transmitted signal comprises a plurality of subcarriers, and further wherein each subcarrier contains more than one and potentially all symbols transmitted in a given frame. The IS-OFDM transmitted signal is at a data rate that is equal to the data rate of the input data stream via the use of P/S converters.

Abstract: Aspects of the present invention provide MAC enhancements to support the PHY features of a MIMO-OFDMA framework. The MAC enhancements involve DL burst assignment to support adaptive MIMO transmission, UL burst assignment to support adaptive MIMO transmission, fast feedback channel operation to support wireless terminal dynamic feedback of MIMO mode selection, for example space time transmit diversity (STTD) or spatial multiplexing (SM), and/or permutation mode selection, for example diversity or adjacent subcarrier mode, dynamic CQICH allocation and de-allocation and the use of CQICH_ID for DL burst allocation. One or more of these enhancements is included in a given implementation. Methods are also provided for implementing the MAC enhancements.

Abstract: Techniques are provided for determining a capacity allocation in a multi-tiered computing system. In one aspect of the invention, a technique for designing capacity allocation for a multi-tiered computing system, each tier of the computing system having one or more computing devices (e.g., servers), comprises the following steps/operations. Input parameters relating to capacity allocation are obtained. A capacity allocation is computed based on at least a portion of the input parameters, the capacity allocation being computable such that one or more end-to-end performance measures are substantially satisfied for multiple service classes. The capacity allocation computation may minimize a cost function.

Abstract: A wireless communication method includes generating and transmitting an OFDM signal containing a first OFDM symbol possessing a first transmitting pilot signal and a second transmitting pilot signal respectively allocated to a first subcarrier and a second subcarrier being symmetric with respect to a center frequency on a frequency axis, and a second OFDM symbol possessing a third transmitting pilot signal and a fourth transmitting pilot signal respectively allocated to the first subcarrier and the second subcarrier, wherein a difference between a product of a first transmitting pilot signal and a complex conjugate of a fourth transmitting pilot signal and a product of a third transmitting pilot signal and a complex conjugate of a second transmitting pilot signal is non-zero.

Abstract: Embodiments of cyclic diversity systems and methods are disclosed. One system embodiment, among others, comprises a logic configured to cyclically advance, or perform the periodic equivalent of the same, one or more sections of an orthogonal frequency division multiplexing (OFDM) packet relative to the OFDM packet to be transmitted on a first transmit antenna, the packet having the one or more cyclically advanced sections to be transmitted on a second transmit antenna, the duration of the cyclic advance having a duration less than a guard interval.

Abstract: A method of demodulating a signal in a transmission system where the modulation includes several substantially orthogonal subcarriers, and the vector of the propagation channel H[n,k] is known or the received signal includes at least pilot symbols emitting reference data. The method includes at least one step of estimating the symbol a[n,k] emitted on the kth subcarrier of the nth symbol of the modulation using a recombination step weighting the various signals received after synchronization and demodulation x[n,k].

Abstract: Disclosed is a demodulation method for enhancing decoding performance of information bits in a constant-amplitude multi-code biorthogonal modulation communication system, which performs encoding to cause the level of a transmission symbol to be constant.

Abstract: A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are generated using at least one timing signal. At least one of the predetermined number of bins includes a pilot tone sub-symbol having a frequency corresponding to the clock signal. The communications system also includes a receiver for receiving the OFDM/DMT symbols from the transmission medium. The receiver demodulates the received symbols using at least one timing signal. The receiver has a first pilot tone search mode of operation in which the receiver adjusts its timing signal to scan the frequency range of the predetermined number of bins looking for the pilot tone sub-symbol and identifies the bin including the pilot tone sub-symbol.

Abstract: A controller in a transceiver for radio communications in which the same frequency is shared between multiple communications systems is disclosed that includes: a cyclic autocorrelation value calculation part configured to calculate the cyclic autocorrelation value of a first one of the communications systems from a received signal; and a data transmission authorization part configured to determine whether to authorize data transmission in a second one of the communications systems based on the calculated cyclic autocorrelation value of the first one of the communications systems.

Abstract: In one embodiment, a method includes receiving received signal strength data, computing an aggregate square error surface based on the received signal strength data, computing a probability surface by applying a probability density function to the aggregate error surface, and computing a mean location of a wireless node.

Abstract: The apparatus includes a receiver unit which receives data; and a guard interval combining unit which combines the whole of the guard interval of the data, which is received by the receiver unit, with the valid symbol. This arrangement makes it possible to efficiently improve reception characteristic by effectively using the guard interval, while suppressing the apparatus size and the cost.

Abstract: A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are generated using at least one timing signal. At least one of the predetermined number of bins includes a pilot tone sub-symbol having a frequency corresponding to the clock signal. The communications system also includes a receiver for receiving the OFDM/DMT symbols from the transmission medium. The receiver demodulates the received symbols using at least one timing signal. The receiver has a first pilot tone search mode of operation in which the receiver adjusts its timing signal to scan the frequency range of the predetermined number of bins looking for the pilot tone sub-symbol and identifies the bin including the pilot tone sub-symbol.

Abstract: An apparatus and method is provided to process a digital signal in an orthogonal frequency division multiple access (OFDMA) wireless communication system. In the apparatus, a memory stores the number of subcarriers allocated to a mobile terminal and stores an inverse discrete Fourier transform (IDFT) coefficient. A controller outputs a mode selection signal indicating a transmission mode or a reception mode. An inverse fast Fourier transform (IFFT) block multiplies a first result obtained by determining a bitwidth for the IDFT coefficient according to the number of subcarriers by a second result obtained by determining a bitwidth for data according to the number of subcarriers.

Abstract: A method of data transmission according to one embodiment of the invention includes encoding a set of data values to produce a corresponding series of ordered n-tuples. The method also includes transmitting, according to the series of ordered n-tuples, a plurality of bursts over a plurality n of frequency bands. Specifically, for each of the plurality of bursts, a frequency band occupied by the burst is indicated by the order within its n-tuple of an element corresponding to the burst. A bandwidth of at least one of the plurality of bursts is at least two percent of the center frequency of the burst. Information is encoded into an additional modulation, e.g., amplitude, width or polarization modulation, of at least one of the plurality of bursts.

Abstract: Techniques, apparatus, and systems are described for providing an orthogonal frequency division multiplexing (OFDM) receiving apparatus. An orthogonal frequency division multiplexing (OFDM) receiving apparatus includes a fast Fourier transform (FFT) start point estimating unit to detect a minimum symbol interference point of a received OFDM signal and identify a FFT start point. The apparatus includes a FFT operation performing unit to communicate with the FFT start point estimating unit and to perform a FFT operation at the FFT start point identified by the FFT start point estimating unit. The apparatus includes a phase modifying unit to communicate with the FFT start point estimating unit and to modify a phase of an output of the FFT operation performing unit. Also, the apparatus includes a decoding unit to communicate with the FFT operation performing unit and to decode the phase modified output of the FFT operation performing unit.

Abstract: A method for detecting a preamble location in a multiple preamble OFDM (Orthogonal Frequency Division Multiplexing) system is disclosed. An OFDM signal is generated with a plurality of frames, and each of the frames includes symbols and a predetermined preamble symbol. A maximum FDDC (Frequency Domain Differential Correlator) value is computed for each of the symbols in some of the frames. The preamble location in a frame is determined by summing the maximum FDDC value for each symbol at a same frame location in consecutive frames of the OFDM signal.

Abstract: A network troubleshooting framework is described. In an implementation, a method includes generating a first estimation of network performance by a simulator based on network settings obtained from a network, estimating the new performance under an alternative setting by providing the alternative setting to the network simulation and observing the simulation output, repeating the procedure for other alternative settings, and suggesting the alternative setting that improves network performance.

Abstract: Embodiments of multiple input multiple output wireless communication systems, associated methods and data structures are generally described herein.

Abstract: Method for generating reference signal sequence using grouping is explained. In this method, base sequences are grouped such that each group contains at least one base sequence of each length, so UE(s) can use various length sequences as a reference signal. And in this method, inter cell interference caused by using various length sequence as a reference signal sequence can be minimized by grouping sequences having the high cross correlation relation.

Abstract: A method and apparatus is disclosed for reducing multi-user processing at the receiver in wireless communication systems. Detected codes are grouped according to channel impulse response and a parent code is identified for each group of detected codes. A matrix A is constructed and joint detection is performed using the identified parent codes. Data symbols of the detected codes are obtained from the data symbols of the identified parent codes.

Abstract: Access to a wireless communication system (100) by a subscriber station (101-103) is facilitated by selecting (705) an access sequence from a set of sequences that have been identified to have a low average of peak-to-average-power-ratios of access signals generated by the set of sequences and also based on a good cross-correlation of the access signals; forming (714) the access waveform by generating an access signal using the access sequence and appending in the time domain a cyclic prefix to the access signal; and transmitting (715) the access waveform. In some implementations, the access waveform is cyclically shifted (820) before the cyclic prefix is appended, and in some implementations, the signal is transmitted (710, 810) in a randomly selected sub-band of an access interval.

Abstract: Data to be transmitted via a MIMO communication system having NT transmission paths is divided into M multiple streams and each stream is transmitted from one of the transmission paths of the MIMO system at a rate that is smaller than the rate the transmission path is capable of transmitting. The MIMO communication system is typically adapted to operate in conformity with a known standard, such as IEEE 802.11, and thus has electrical properties conforming to such standards. For example, if the communication system includes two transmission paths each adapted to transfer data at the rate of 48 Mbps per channel, the communication system is operated at a slower bit rate of, for example, 18 Mbps per channel to attain a range that is longer than that of a single spatial transmitter having an equivalent data rate of 36 Mbps.

Abstract: A multiple-input-multiple output (MIMO) transmitter for transmitting a group of sequential orthogonal frequency division multiplexed (OFDM) symbols on a time-division duplexed (TDD) channel in accordance with an IEEE 802.16 standard using a plurality of antennas. The MIMO transmitter comprises a spatial-frequency parser to parse a block of bits into spatial-frequency blocks of a variable number of coded bits, and subcarrier modulators to individually modulate OFDM subcarriers with the spatial-frequency blocks in accordance with spatial-frequency subcarrier modulation assignments to generate groups of symbol-modulated subcarriers. The TDD channel comprises a plurality of the groups of the OFDM subcarriers, and the OFDM subcarriers within each group of subcarriers and within each group of sequential OFDM symbols have the same spatial-frequency subcarrier modulation assignments.

Abstract: The invention is related to a network element, comprising: means for receiving feedback information from the user device; means for creating a first orthogonality measure by using the feedback information; means for creating a second orthogonality measure by comparing transmission resources; means for transmitting information to at least one user device.

Abstract: A method and apparatus are provided for frequency synchronization in an Orthogonal Frequency Division Multiplexing (OFDM) system, wherein the method includes the steps of transmitting OFDM symbols in such a manner that a data symbol size of a particular OFDM symbol in each frame is set to be smaller than a data symbol size of a typical OFDM symbol within the frame, receiving the OFDM symbols and calculating respectively, correlation coefficients of the particular OFDM symbol based on both a time interval of corresponding data symbols and a time interval of data symbols of the typical OFDM symbol, taking respectively phases of corresponding correlation coefficient calculated from the particular OFDM symbol and estimating a decimal part of a frequency offset, and determining an integer part of the frequency offset corresponding to the decimal part of the frequency offset, thereby estimating an entire frequency offset and acquiring the frequency synchronization.

Abstract: The invention concerns a method for distributing data on an OFDM time-frequency grid for data transmission from and to mobile terminals in a mobile network allowing for coordination of interferences between different cells of the mobile network and adaptive subcarrier frequency allocation to mobile terminals, whereby subcarrier frequencies of the OFDM time-frequency grid are gathered in frequency patterns, the frequency patterns are constructed to accommodate the use of pilot subgrids, a set of frequency patterns is changed in a pilot compatible manner between frequency diverse and frequency selective frequency patterns, and said frequency patterns are allocated to mobile terminals for data transmission , a base transceiver station, a base station controller and a mobile network therefor.

Abstract: The invention concerns a method for distributing data on an OFDM time-frequency grid for data transmission from and to mobile terminals in a mobile network accommodating the use of pilot subgrids suitable for channel estimation, whereby said OFDM time-frequency grid comprises different frequency patterns, subcarrier frequencies of said different frequency patterns are interleaved, in at least one interleaving interval, as many cyclic shifts of the respective part of the frequency patterns are performed, rotating the allocation of the subcarrier frequencies to the different frequency patterns, as must be performed so that the distribution of the pilot subgrids over the frequency patterns leads for each pilot subgrid to no more than a maximum defined number of pilots that lie within each frequency pattern, a base transceiver station, a base station controller and a mobile network therefor.

Abstract: A method for generating a signal is presented. The method includes selecting a first set of carrier frequencies that are integral multiples of a first frequency interval, and selecting a second set of carrier frequencies that are integral multiples of a second frequency interval. The second frequency interval is an integral multiple of the first frequency interval and the second set is a subset of the first set. The method includes, for each of one or more signal carrier frequencies in the second set, selecting a plurality of associated carrier frequencies in the first set including a peak carrier frequency having substantially the same value as the signal carrier frequency, and modulating waveform frequency components at each of the selected plurality of associated carrier frequencies according to the same data value.

Abstract: A source node of a communication system selects one of a direct mode, a multi-hop mode, and a superposition mode as a transmission mode to be used for signal transmission from the source node to a destination node, taking into account data rates for a link between the source node and the destination node, a link between the source node and a delay node, and a link between the relay node and the destination node, thereby increasing the data rate, i.e., the throughput, of the entire communication system.

Abstract: A secondary source of dispatch information is provided in the event of a failure of a primary source of dispatch information. The second source of dispatch information can be accessed electronically by service technicians in the field when the primary source of dispatch information fails so that service technicians do not have to contact operators in a central office to obtain the dispatch information. The secondary source of dispatch information can distribute the dispatch information in a number of ways including e-mail, web and other methods.

Abstract: A digital modulation system provides enhanced multipath performance by using modified orthogonal codes with reduced autocorrelation sidelobes while maintaining the cross-correlation properties of the modified codes. For example, the modified orthogonal codes can reduce the autocorrelation level so as not to exceed one-half the length of the modified orthogonal code. In certain embodiments, an M-ary orthogonal keying (MOK) system is used which modifies orthogonal Walsh codes using a complementary code to improve the auto-correlation properties of the Walsh codes, thereby enhancing the multipath performance of the MOK system while maintaining the orthogonality and low cross-correlation characteristics of the Walsh codes.

Abstract: The present invention discloses a method of idle mode control in an orthogonal frequency-division multiplexing (OFDM) system. By superposing idle mode control channels on a frame synchronization pattern in the frame header of an OFDM frame, mobile terminals at a low migration rate will be switched into idle mode during packet service transmission intermission period. The mobile terminals in idle mode needn't do FFT to check whether there is any packet to be received after receiving every frame, thereby the power energy of the mobile terminals is greatly saved.

Abstract: A device and method for communicating by a mobile communication terminal in communication with a base station. The method according to an embodiment includes exchanging a frame of data with the base station. The frame of data includes a) a plurality of first subframes each having a first number of orthogonal frequency division multiple access (OFDMA) symbols, and b) a plurality of second subframes each having a second number of orthogonal frequency division multiple access (OFDMA) symbols different from the first number.

Abstract: Disclosed are an apparatus and a method for generating a preamble signal for cell identification in an OFDM mobile communication system. The method includes the steps of generating a Walsh code symbol for a cell identification by combining Walsh codewords having a predetermined length and generating the preamble signal through multiplying the Walsh code symbol by a pseudo noise (PN) code having a length identical to a length of the Walsh code symbol.

Abstract: A method and system for joint encoding multiple independent information messages are disclosed. In one embodiment, a system includes an encoder configured to encode each of the independent information messages to produce respective encoded bits, and a first multiplexer configured to multiplex each of the independent information messages. A joint block encoder encodes the multiplexed independent information messages to produce encoded common parity bits shared by all independent information messages, and a second multiplexer multiplexes the respective encoded bits from all independent channel encoders and the encoded common parity bits from the joint block encoder to produce the final output.

Abstract: For communicating data frames, a respective data frame is transmitted from each of a plurality of transmitter antennas of a transmitter. In addition, a power of any data field that is of a predetermined data type within the respective data frames is boosted to a maximum available power of the transmitter. Thus, total available power of a transmitter is efficiently used for transmitting data fields of the predetermined data type such as channel estimation preambles transmitted with time orthogonality.

Abstract: An apparatus and method for multiplexing packets for broadcast services in a mobile communication system based on orthogonal frequency division multiplexing (OFDM). The OFDM system has a transmission structure in which one slot includes at least two symbols, and each symbol includes a plurality of subcarriers. Different broadcast service packets received from at least two channels are multiplexed into one slot and a result of the multiplexing is transmitted. Overhead information of the channel packets multiplexed into the one slot is generated and transmitted.

Abstract: A wireless communication device including a sending data amount determination unit, a data sending unit, a monitor function unit, a transmission control data producing unit, a transmission control data sending unit, a data reception unit, and an application I/F (interface) unit. The transmission control data sending unit includes a transmission control data separation unit, a transmission control data replication unit, and a data mapping unit.

Abstract: A transmitting/receiving apparatus and method for packet retransmission in a mobile communication system. Upon request for a retransmission from a receiver, a transmitter inverts initially transmitted coded bits if the retransmission is odd-numbered for the same data, modulates the inverted bits, and transmits the modulated bits to the receiver. Then the receiver recovers the coded bits by demodulation. If the coded bits are retransmitted an odd number of times, the receiver decodes the coded bits after inversion. Thus the error probabilities of initial transmission bits and retransmission bits are averaged in effect and decoding performance is improved.

Abstract: A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection comprises a subscriber measuring channel and interference information for subcarriers based on pilot symbols received from a base station, the subscriber selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, and receiving an indication of subcarriers of the set of subcarriers selected by the base station for use by the subscriber.

Abstract: Embodiments of the present invention include a method for performing joint time synchronization and carrier frequency offset estimation in a wireless communication system, comprising steps of: on a transmitter: performing frequency domain spreading and interleaving on input data by using a predetermined spreading factor (SF) to generate a frequency domain training symbol; performing Inverse Discrete Fourier Transformation (IDFT) on the generated frequency domain training symbol to generate a first time domain training symbol; reversely copying the generated first time domain training symbol to a second time domain training symbol such that a complete training sequence is formed; and on a receiver: detecting an average power of received signals to judge the coming of a training sequence, and performing coarse frame synchronization; performing joint fine frame synchronization and carrier frequency offset estimation based on a received training sequence; and compensating for the carrier frequency offset based on

Abstract: A transmission method for transmitting an orthogonal frequency division multiplexing signal the method includes composing, on a per unit time basis, a plurality of carrier groups each composed of one or more subcarriers, assigning, on a per unit time basis, transmission data for a plurality of transmission destination terminals, to the plurality of carrier groups and transmitting the assigned transmission data.

Abstract: A signal processing system according to various aspects of the present invention includes an excursion signal generator, a scaling system and a filter system. The excursion signal generator identifies a peak portion of a signal that exceeds a threshold and generates a corresponding excursion signal. The scaling system applies a real scale factor to contiguous sets of excursion samples in order to optimize peak-reduction performance. The filter system filters the excursion signal to remove unwanted frequency components from the excursion signal. The filtered excursion signal may then be subtracted from a delayed version of the original signal to reduce the peak. The signal processing system may also control power consumption by adjusting the threshold. The signal processing system may additionally adjust the scale of the excursion signal and/or individual channel signals, such as to meet constraints on channel noise and output spectrum, or to optimize peak reduction.

Abstract: An apparatus and method for receiving a ranging signal in an OFDMA mobile communication system are provided. The ranging signal receiving apparatus including, a ranging subchannel extractor for extracting subcarrier values with a ranging signal from a (FFT) signal; a plurality of multipliers for code-demodulating the sub-carrier values by multiplying them by a plurality of ranging codes; each of a plurality of correlators for calculating a plurality of differential correlations in a code-demodulated signal received from a corresponding multiplier; each of a plurality of inverse fast Fourier transform (IFFT) processors for IFFT-processing differential correlations received from a corresponding correlator by mapping the differential correlations to predetermined subcarriers and each of a plurality of maximum value detectors for detecting a maximum value in an IFFT signal received from a corresponding IFFT processor and calculating a timing offset using an IFFT output index having the maximum value.

Abstract: A communication network which can use communication bandwidth effectively. Spreading codes of a first and a second code length are assigned for every communication terminal interfaces connected to the same communication network. The spreading codes of the first code length are used for data communications. The spreading codes of the second code length are used for the control communications between the interfaces and the sever. The interfaces and the server receives mixed signals of the data and the control signals. When the received signals are decoded using the spreading code of the first code length, control signal components became equal to or lower than the noise level. When the received signals are decoded using the spreading code of the second code length, data components became equal to or lower than the noise level. Therefore, the interfaces and the server can extract one of these signal components.

Abstract: A communication device converts a bit stream to multiple symbols and provides encryption at a physical layer by shifting a phase of each symbol of the multiple symbols to produce multiple encrypted symbols. Each encrypted symbol of the multiple encrypted symbols is modulated with an orthogonal subcarrier to produce at least one modulated subcarrier and the at least one modulated subcarrier is then transmitted via a wireless link. On a receive side, a receiving communication device receives the transmitted, encrypted symbols and provides decryption at a physical layer by shifting a phase of each encrypted symbol in correspondence with the phase used to encrypt the symbol at the transmit side.