Abstract: An apparatus includes an estimator that includes a receiver that receives a plurality of frequency-domain symbols. Each symbol includes at least one of a plurality of pilot samples and a plurality of data samples. The estimator also includes a framer that observes the at least one of the plurality of pilot samples and the plurality of data samples in adjacent symbols, and a calculator that calculates an integer carrier frequency offset (CFO) estimate based on a reliability metric based on the at least one of the plurality of pilot samples and the plurality of data samples that are included in the frequency-domain symbols.

Abstract: A system includes an estimation module, a processing module, and a control module. The estimation module receives a signal having N sub-carriers and generates N first estimates for channel gains of the N sub-carriers, where N is an integer greater than 1. The processing module generates N second estimates based on the N first estimates. The control module generates N differences between each of the N first estimates and corresponding ones of the N second estimates and estimates (i) a channel gain of the signal and (ii) a preamble sequence in the signal based on the N differences.

Abstract: A method and apparatus for transmitting and receiving a signal in a wireless communication system. The wireless communication system includes a transmitter with at least four transmit antennas and a receiver with at least one receive antenna. Space Frequency Block Coding (SFBC) processes are performed for input signals on a basis of two antenna pairs. Signal blocks whose number corresponds to the number of transmit antennas are output. A Space Time Block Coding (STBC) process is performed for the signal blocks generated according to the antenna pairs. Signals carried by single carriers are transmitted through the at least four transmit antennas mapped to the signal blocks.

Abstract: A phase-shift based pre-coding scheme used in a transmitting side and a receiving side that has less complexity than those of a space-time coding scheme, that can support various spatial multiplexing rates while maintaining the advantages of the phase-shift diversity scheme, that has less channel sensitivity than that of the pre-coding scheme, and that only requires a low capacity codebook is provided.

Abstract: A transmitting entity transmits a “base” pilot in each protocol data unit (PDU). A receiving entity is able to derive a sufficiently accurate channel response estimate of a MIMO channel with the base pilot under nominal (or most) channel conditions. The transmitting entity selectively transmits an additional pilot if and as needed, e.g., based on channel conditions and/or other factors. The additional pilot may be adaptively inserted in almost any symbol period in the PDU. The receiving entity is able to derive an improved channel response estimate with the additional pilot. The transmitting entity sends signaling to indicate that additional pilot is being sent. This signaling may be embedded within pilot symbols sent on a set of pilot subbands used for a carrier pilot that is transmitted across most of the PDU. The signaling indicates whether additional pilot is being sent and possibly other pertinent information.

Abstract: Aspects of a method and system for selective equalization enablement based on modulation type may be found in a method for processing a radio frequency (RF) signal that comprises receiving a Bluetooth signal via an RF channel, detecting a modulation type of the received Bluetooth signal, and selecting an equalization circuit for processing the received Bluetooth signal based on the detected modulation type. The method may also comprise determining a data rate based on the detected modulation type.

Abstract: An embodiment of the present invention includes a transceiver for use in a multi-input-multi-output (MIMO) Orthogonal Frequency Domain Multiplexing (OFDM) wireless communication system. The transceiver decodes and remodulates certain signal fields and uses the same to update the coefficients of a frequency equalizer thereby improving channel estimation and extending training.

Abstract: An inter-carrier interface removal device can improve estimation accuracy of inter-carrier interference caused by Doppler shift in a received multi-carrier signal moving at a high speed, and a reception characteristic of the multi-carrier signal after removing the inter-carrier interference.

Abstract: A transmitting device is provided that generates OFDM symbols by identifying a sampling frequency of input data that is input from an external device, determining a number of inverse Fourier transform sample points and a number of sampling points of a redundant data portion in accordance with the identified sampling frequency, and subjecting the input data to OFDM modulation using the determined number of sampling points. The transmitting device then transmits the generated OFDM symbols.

Abstract: Disclosed herein are apparatus, methods and computer program products for performing cell acquisition and pilot sequence detection in a cellular telecommunications system such as, for example, an OFDM system. In the apparatus, methods and computer program products, a primary synchronization channel sequence and a secondary synchronization channel sequence are transmitted by a base station in a sub-frame of an OFDM downlink frame. In one embodiment, the primary synchronization channel sequence, secondary synchronization channel sequence, and system information are mapped to a plurality of sub-carriers in an FDM signal. At the user equipment, coarse synchronization is performed during cell acquisition by performing a cross correlation between the signal and a reference primary synchronization channel sequence stored in a memory of the user equipment.

Abstract: A method for transmitting a digital signal is described, wherein the digital signal is to be transmitted by a plurality of antennas and a 2-domain pre-transformation is carried out, i.e., in course of a pre-transformation modulation symbols assigned to subcarriers having different frequencies and assigned to subcarriers sent by different antennas are linearly combined.

Abstract: A transmitting apparatus, a receiving apparatus, and a communication system are provided that allow a reduction in a frame loss due to interference caused by use of the same channel. A transmitting apparatus disposed in a base station includes a GPS receiver for receiving a GPS signal, a timing generator for controlling respective function blocks in accordance with the GPS signal and an inter-base-station control signal so as to precisely synchronize the timing of frame transmission among base stations, the front-end transmission processing unit including for converting transmission information into transmission time slots, a frame generator for generating a frame including a plurality of time slots and one frame guard, and a back-end transmission processing unit for transmitting the generated frame as a radio signal.

Abstract: A transmitter that has a determination unit for determining a plurality of symbols (301) such that each symbol (301) has a tail component (302) and the plurality is determined in such a way that the tail components (302) are substantially equal and a tone generation unit for arranging the plurality of symbols (301) to form a plurality of long preambles (300) such that the plurality of long preambles (300) are tone-interleaved.

Abstract: The present invention relates to a method for data transmission in a communication system. The method includes determining, at the transmitter, whether to transmit data signal using a single codeword or two codewords. When it is determined that the single codeword transmission is used, coding, by the transmitter, a control signal by using a first signal format, with the control signal coded by the first signal format carrying information regarding the single codeword. When it is determined that the two codewords transmission is used, coding, by the transmitter, the control signal by using a second signal format, with the control signal coded by the second signal format carrying information regarding both of the two codewords. The method also includes transmitting the data signal and the control signal according to the determined transmission format from the transmitter to the receiver.

Abstract: Method and apparatus for block boundary detection is described. A signal is received. The signal is quantized to provide a quantized signal to at least one correlator, the quantized signal being a sequence of samples. The sequence of samples and a reference template including totaling partial results from the at least one correlator are cross-correlated to provide a result, the result being a symbol timing synchronization responsive to the cross-correlation also known as block boundary detection. The cross-correlation is provided in part by combining by exclusive-ORing a regression vector obtained from the sequence of samples and a coefficient term vector obtained from the reference template.

Abstract: A system and related methods for introducing intra-channel spatial diversity within a multi-carrier wideband communication channel is presented. In accordance with one aspect of the present invention, developed more fully below, a method is presented comprising receiving information for transmission to a receiver, and generating a plurality of sub-carriers to redundantly transmit the information to a user over a multi-carrier wireless communication channel, wherein each of the sub-carriers is dynamically modified by a set of complex weights to ensure that each of the sub-carriers of the wireless communication channel propagates along a different physical path to the receiver.

Abstract: A communication device for transmitting orthogonal frequency division multiplexed (OFDM) signals in a wireless communication system. The device includes a plurality of antenna elements that transmit the OFDM signals to a receiver over a plurality of transmission channels in the wireless communication system. The device also generates weight coefficients applied to each of the plurality of subcarrier signals, and controls an amplitude and/or phase of the plurality of subcarrier signals as a function of said weight coefficients.

Abstract: A transmission method for use in a multi-hop wireless communication system is provided. The method includes, for two apparatuses having overlapping transmission coverage areas, one of the two said apparatuses being an intermediate apparatus, transmitting a first transmission signal from a first one of those apparatuses in a first transmission window of a particular transmission interval and transmitting a second transmission signal from the second one of those apparatuses in a second transmission window of the particular transmission interval but not in said first transmission window, so that a communication apparatus located in the coverage areas of both the first and second apparatuses can receive said first transmission signal substantially without interference from said second transmission signal.

Abstract: A communication device for receiving transmitted orthogonal frequency division multiplexed (OFDM) signals in a wireless communication system. The device includes a plurality of antenna elements to receive a plurality of OFDM signals transmitted from a transmitter via a plurality of transmission channels. The device performs channel estimation processing and decoding processing on the plurality of received OFDM signals, and weights the plurality of received OFDM signals by weight vectors chosen to improve a performance of the plurality of received OFDM signals.

Abstract: A method of performing resource allocation in OFDM transmission is disclosed. The method includes performing a partitioning of the OFDM spectrum into a number of predefined regions (Rij, R?ij) of sub-carriers (SCi) for a number of OFDM transmission cells, assigning at least one respective transmission-related characteristic to the regions of sub-carriers, and allocating the resources for communication with at least one user equipment in at least one region of sub-carriers based on the partitioning and dependent on the characteristic assigned to the regions of sub-carriers. This allows fast resource allocation with low signaling effort, as well as fast adjustment to changing system settings or changing systems conditions, while providing a possible alternative to costly handover procedures.

Abstract: To obtain maximum throughput in accordance with characteristics of a propagation path, a radio transmission device having a plurality of transmitting antennas (18a, 18b) for transmitting a transmission signal in units of sub-carriers by performing spatial multiplexing or without performing spatial multiplexing is provided that includes a sub-carrier modulation part 11 modulating the input transmission signal for each sub-carrier, a transmission signal allocation part 13 allocating the transmission signal modulated for each of the sub-carriers to each of the transmitting antennas, and a transmission control part 12 that determines a multiplexing number for performing spatial multiplexing for each sub-carrier based on information received from another radio communication device as an opposite party, and outputs the determined multiplexing number to the sub-carrier modulation part and the transmission signal allocation part.

Abstract: A communications system (100) includes a segmenter (204) for dividing a plurality of bits into a first segment and a second segment and a symbol mapper (208) for generating a plurality of symbols based on the first segment. The system also includes a co-set selector (214) for selecting a plurality of co-set waveforms from a plurality of orthogonal waveforms based on a co-set address defined by the second segment, a number (K) of the plurality of co-set waveforms being less than a number (N) of the plurality of orthogonal waveforms. The system further includes a modulator (210) for modulating the plurality of symbols based on the plurality of co-set waveforms.

Abstract: A wireless communication method and apparatus are provided. The wireless communication method includes receiving a packet including information of a device connected to a wireless network, the wireless network uses a first channel and a second channel supporting different transmission capabilities, and storing the information of the device included in the packet.

Abstract: Methods and apparatus for a single-wire serial communication system are disclosed herein. In one embodiment, a method includes defining a predetermined short pulse as data to be transmitted and a predetermined long pulse as a data separator for the data to provide serial communication for a data stream.

Abstract: A frequency synthesizer for generating a plurality of frequencies of a MB-OFDM UWB system is disclosed, wherein the frequencies include first to fourteenth frequencies from low to high and any of the adjacent two frequencies differs by a basic intervallic frequency. The frequency synthesizer includes a phase locked loop generating an initial signal with a frequency equal to the second frequency, an intervallic frequency generator generating first to third intervallic frequencies from low to high and all being integers times the basic intervallic frequency and generating a forth intervallic frequency equal to the basic intervallic frequency, and first to third mixers connected in series, respectively receiving the fourth intervallic frequency, one of the first to third intervallic, and the first intervallic frequency, to respectively generate the first to third frequencies, the fourth to ninth and the thirteenth to fourteenth frequencies, and the tenth to twelfth frequencies.

Abstract: In a wireless local area network (WLAN) that includes high-throughput communication devices with multiple antennas and legacy communication devices with single antennas, training tones are transmitted over a plurality of spatial channels during a first portion of an orthogonal frequency division multiplexed (OFDM) packet-training preamble. The training tones are interspersed among subcarrier frequencies of the spatial channels. The training tones are retransmitted during a second portion of the packet-training preamble. The training tones are shifted among the subcarrier frequencies of the spatial channels during the retransmission allowing a high-throughput receiving station to perform a channel estimation on different subcarrier frequencies of the spatial channels. The legacy communication devices may receive and process the training tones and may set their network allocation vector to refrain from communicating during a subsequent interval.

Abstract: The method comprises a phase, applied by the first equipment (A), for estimating a first time of flight between the two equipments (A, Z) corresponding to the signal transmission time to go from one equipment to the other along a propagation path, called the “strongest path”, taken by a main part of the energy of the signals, a phase for estimating a difference in time of flight comprising the sending of a channel sounding frame by the first equipment to the second and, from the received radio signals corresponding to said channel sounding frame, estimating a difference in time of flight between the strongest propagation path and a first propagation path, performed by the second equipment, and a phase for calculating the distance between the two equipments (A, Z) comprising the determination of a second time of flight by subtracting the estimated difference in time of flight from the estimated first time of flight (E30) and calculating the distance between the two equipments from the duly determined second ti

Abstract: A method for transmitting channel quality information (CQI) from a receiver station to a transmitter station in a wireless communication system which includes diversity mode consisted of spaced apart subcarriers and band AMC mode consisted of a number of bands comprised of a predetermined number of adjacent subcarriers. The method comprises the steps of transmitting an average CINR(Carrier to Interference and Noise Ratio) value for a full frequency band if the receiver station operates in the diversity mode; transmitting a differential CINR of a predetermined number of bins if the receiver station operates in the band AMC mode.

Abstract: An efficient channel estimation system and method provides good performance under high Doppler conditions and is suitable for OFDM systems such as DVB-T. A number of different pilot interpolations techniques enable the estimation of channel for the OFDM systems. For 2k and 4k modes, the channel is estimated using the preceding symbol, the present symbol, and two succeeding symbols. For an 8k mode, only one future symbol is used to estimate the channel.

Abstract: A communication network system sets communication parameters which enable an operation under a maximum possible communication rate in a situation where a transmission path has cyclic noise/impedance fluctuations. A transmission/reception apparatus 100 transmits training packets for checking the state of the power line at two distinct points in time. A transmission/reception apparatus analyzes SNR at each carrier frequency, and stores an SNR evaluation result. The transmission/reception apparatus compares two SNR evaluation results which are obtained through two instances of a channel estimation algorithm, selects an SNR evaluation result which dictates a faster PHY rate, and transmits it to the transmission/reception apparatus. The transmission/reception apparatus changes modulation/demodulation rules based on the received SNR analytical result.

Abstract: To remove DC offset from received data symbols having cyclic prefixes in a data communication system, means (5) are provided for determining the location of the cyclic prefixes, means (3) are provided for calculating the DC offset by calculating a mean value of at least one data symbol without its cyclic prefix and means (4) are provided for subtracting the calculated DC offset from said at least one data symbol with its cyclic prefix.

Abstract: The present invention relates to a method for data transmission in a communication system. The method including, determining, at the transmitter, whether to transmit data signal using a single codeword or two codewords, when it is determined that the single codeword transmission is used, coding, by the transmitter, a control signal by using a first signal format, with the control signal coded by the first signal format carrying information regarding the single codeword, when it is determined that the two codewords transmission is used, coding, by the transmitter, the control signal by using a second signal format, with the control signal coded by the second signal format carrying information regarding both of the two codewords, transmitting the data signal and the control signal according to the determined transmission format from the transmitter to the receiver.

Abstract: A method and apparatus for transmitting data in a communication system. In the apparatus, a repeater repeatedly processes an input signal a predetermined number of times. A Space-Frequency Block-Coded (SFBC) encoder performs SFBC coding on the repeatedly processed input signals, and outputs at least two signal blocks in parallel. A cyclic prefix (CP) inserter inserts a CP in the signal blocks and transmits the CP-inserted signal blocks via associated transmission antennas using a single carrier.

Abstract: A radio device operable to compensate for a large RF filter group delay variation is provided. The radio device includes a receiving unit operable to receive an OFDM signal that comprises pilot subcarrier signals and data subcarrier signals. The radio device further includes a group delay (GD) compensator, operable in frequency domain, and configured to perform phase rotation to correct a group delay individually on tones of an OFDM symbol. The phase rotation is calculated as a function of the phase shifts of the received pilot subcarrier signals and subcarrier index.

Abstract: A communication device carries out communication using N number of communication channels, where N is an integer not less than 2. The communication device includes interleavers that shuffle a data series, which is meant to be transmitted over the N number of communication channels, in at least two directions from among a time direction, a space direction, and a frequency direction, and deinterleavers that shuffle the data series back to obtain the original data series.

Abstract: An adaptive modulation and coding (AMC) method for data transmission by various modulation orders and coding rates is provided. A signal-to-noise ratio (SNR) of a transmission channel is estimated. Quality of service (QOS) parameters are provided, defining maximum allowable delay and packet error rate (PER). A retransmission limit is determined from the maximum allowable delay. An optimum packet length is determined based on the QOS parameters and the SNR. A modulation order and a coding rate most suitable for the estimated SNR and the defined PER are selected based on the optimum packet length and the retransmission limit.

Abstract: A radio communication system for carrying out communications between radio stations by modulating a plurality of signal sequences to be transmitted and received into at least one frequency channel assigned to each of a plurality of cells is formed by a channel mapping means for rearranging for each cell a plurality of frequency channels assigned with respect to each cell, and newly assigning particular frequency channels as a transmission and reception band of said signal sequences, and a bandwidth control means for controlling a bandwidth of said assigned frequency channel according to a propagation state of said assigned frequency channel.

Abstract: A method for transmission, by dividing a transmission resource in a time domain subframe into a plurality of equal duration resource elements in a time and frequency domain, segregating the plurality of resource elements into a plurality of resource regions, modulating information to be transmitted to generate a sequence of modulation symbols at a transmitter, mapping the sequence of modulation symbols into the plurality of resource elements in the plurality of resource regions, and transmitting the modulation symbols via a plurality of antennas using the respective corresponding resource elements to a receiver. The mapping of the modulation symbols in at least one resource region is independent of a certain control channel information that is carried in said time domain subframe, and the mapping of the modulation symbols in at least another resource region is dependent upon said certain control channel information that is carried in said subframe.

Abstract: A method for allocating a physical hybrid ARQ indicator channel (PHICH) includes allocating a CDM group according to a cyclic prefix type in consideration of a ratio of the numbers of necessary CDM groups according to spreading factors, and allocating a PHICH to the allocated CDM group. The PHICH includes an ACK/NACK signal multiplexed by code division multiplexing (CDM). Therefore, resources for PHICH transmission are efficiently allocated and a transmission structure can be maintained irrespective of a spreading factor.

Abstract: Systems and methods for orthogonal frequency division multiplexing are provided. In one embodiment, a multi-carrier modem comprising: a receiver configured to de-modulate symbols from at least one of a plurality of spectrally overlapping carrier signals; a transmitter configured to modulate symbols onto at least one of a plurality of the spectrally overlapping carrier signals; a processor coupled to the transmitter, wherein the processor outputs data for transmission by the transmitter, wherein the processor applies an inverse Fourier transform to the data transmitted by the transmitter; and a controller programmed to multiplex both payload data and control data onto a first carrier of the spectrally overlapping carrier signals.

Abstract: Systems and methods for orthogonal frequency division multiplexing are provided. In one embodiment, a multi-carrier modem comprises: a receiver configured to receive a waveform comprising a plurality of spectrally overlapping carrier signals from at least two of a plurality of remotes, the carrier signals are modulated using an inverse Fourier transform; a transmitter; a processor coupled to the transmitter, the processor outputs data for transmission to the transmitter, the processor applies an inverse Fourier transform to the data provided to the transmitter; a controller programmed to instruct the transmitter to transmit timing adjustments to the at least two of the plurality of remotes, the timing adjustments instruct the at least two of the plurality of remotes to adjust transmission timing so that transmitted symbols associated with frames of a predetermined multiframe structure are received in sequence from the at least two of the plurality of remotes based on the structure.

Abstract: A frequency-division multiplexing transmission apparatus for transmitting data in a frequency spectrum specific to both symbol and mobile station, is disclosed. The apparatus encodes transmission data, modulates the encoded data, compresses the time domains of each symbol of the modulated transmission-symbol sequence, repeats the symbols a specified number of times, rearranges each of the symbols of the obtained repetitive-symbol sequence so that they have the same arrangement as the transmission-symbol sequence, generates each phase that changes at a speed specific to each symbol of the transmission-symbol sequence, performs phase rotation specific to the symbols for each symbol of the rearranged repetitive-symbol sequence, generates phase that changes at a speed specific to a mobile station, performs phase rotation specific to the mobile station for the symbol sequence for which the phase rotation was performed, and transmits the phase-rotated symbol sequence.

Abstract: An apparatus and method for positioning a pilot in a transmitter for an Orthogonal Frequency Division Multiple Access (OFDMA) mobile communication system. In the apparatus, a consecutive block assignment determiner determines whether it will assign a consecutive block or a single block in a frequency axis or a time axis. A pilot tone pattern generator determines a pilot pattern in the block by applying a predetermined rule according to the determination result. A pilot tone inserter positions pilots in the block based on the determined pilot pattern.

Abstract: Methods and apparatus for converting original data into a plurality of sub-bands using wavelet decomposition; encrypting at least one of the sub-bands using a key to produce encrypted sub-band data; and transmitting the encrypted sub-band data to a recipient separately from the other sub-bands.

Abstract: A differential STBC transmitting/receiving apparatus in a multiple antenna system using eight or less transmit antennas is provided. In the differential STBC transmitting apparatus, a symbol mapper receives binary data and generates a number of symbols from the binary data, each symbol having a number of bits. A space-time block encoder generates an STBC by encoding the symbols. A differential processor differentially encodes the STBC through feedback and delay. A distribution matrix processor substitutes the differentially coded STBC into a distribution matrix preset according to the number of transmit antennas, and outputs the differential STBC code of the distribution matrix to the transmit antennas.

Abstract: The present disclosure provides a method and apparatus of channel estimation for a wireless communication system. A pilot signal energy is estimated based on received pilot symbols. An estimated traffic signal energy of the traffic signal symbols is estimated based on the received traffic signal symbols, the received pilot symbols and a noise estimate. A traffic to pilot ratio is estimated based on the pilot signal energy and the traffic signal energy.

Abstract: Described is a method for compensation of an OFDM signal propagating through Doppler-distorted, time-varying multipath channels. The method is based on low-complexity post-FFT signal processing. Minimum mean square error combining of signals is performed for signals received at spatially-distributed receiver elements using adaptive channel estimation and phase tracking. Doppler shifts are modeled as a consequence of motion-induced time compression and dilation. The Doppler rate is assumed constant over one OFDM block but can vary between OFDM blocks. Thus a non-constant Doppler shift is accommodated by the method. Non-uniform Doppler compensation across subchannels is based on adaptive estimation and prediction of the Doppler rate. A single adaptively estimated parameter is used to track the phases of all the carriers and channel estimates are updated on a block by block basis.

Abstract: The present invention relates to an orthogonal frequency division multiplexing wireless local area network (LAN) transmitting/receiving system for providing expanded service coverage, and a method thereof. A first OFDM modulation is performed for an even-numbered time, and a second OFDM modulation is performed for an odd-numbered time. A transmitting frame including a plurality of signal fields according to the first and second OFDM modulation is transmitted. The receiving system determines whether a signal field is repeatedly generated in the frame. If the signal field is not repeatedly generated, corresponding demodulation is performed. If repeatedly performed, the signal field is demodulated by using first bit allocation information and second bit allocation information having a ½ value of the first bit allocation information. A data field is demodulated according to the demodulated signal field.

Abstract: A method and apparatus for transmitting and receiving MAP information in a communication system are provided. A base station acquires channel quality information of each mobile station, generates sub-MAPs using MAP information, to which at least one of a coding scheme, a modulation scheme and a repetition scheme is applied, separately for each mobile station according to the channel quality information, and transmits the generated sub-MAPs. A mobile station receives MAP information from the base station, detects a sub-MAP allocated to the mobile station from the received MAP information, and restores the detected sub-MAP to MAP information using at least one of a corresponding decoding scheme, demodulation scheme and repetition scheme corresponding to coding scheme, modulation scheme and repetition scheme applied in the base station, based on channel quality information of the mobile station. Accordingly, system overhead can be reduced.

Abstract: The transmitting side is equipped with chip steering section 30 that performs a chip steering that shifts the allocation of N×M chip elements upon their respective subcarriers by one chip for every transmission unit in sequence, and the receiving side is equipped with a parallel/serial conversion section and an inverse chip steering section that rearranges the allocation of the chip elements shifted in chip steering section 30 back to original.