Abstract: In a method and a transmitter data is transmitted to two mobile stations sharing the same frequency band and the same timeslot. The data is modulated using a quaternary symbol constellation. Further, the data is transmitted to two mobile stations multiplexed on a shared channel comprising two branches and the transmission power for the transmitted data is set in response to the relative gain of the two branches. Hereby, the total system interference is reduced. The method and transmitter further allows for a cellular radio system individual power control loops for the two sub-channels when the system uses MUROS.

Abstract: A physical layer module includes a mapping module and a plurality of gain modules. The mapping module maps a plurality of coded data streams to a plurality of transmit antennas, in which each transmit antenna is associated with a respective radio frequency channel of a plurality of radio frequency channels. Each gain module is associated with a respective radio frequency channel of the plurality of radio frequency channels, and is configured to apply a complex gain to the coded data stream mapped to the respective radio frequency channel associated with the gain module. The complex gain applied by the gain module differs relative to that applied by other gain modules, and corresponds to the transmit antenna associated with the respective radio frequency channel.

Abstract: Aspects of a method and system for near continuous data rate limit adjustment via a plurality of link variables in an energy efficient network. In this regard, power consumption of a network device may be controlled by enabling and/or disabling one or more components in the network device based on an adjustment of a plurality of data rate variables that control a data rate limit at which the network device may communicate. Exemplary data rate variables may comprise a number of active channels of a network link over which the network device communicates, a symbol rate on an Ethernet link over which said network device communicates, an inter-frame gap time on an Ethernet link over which said network device communicates, a signal constellation utilized for representing signals on an Ethernet link over which said network device communicates.

Abstract: A system including a first receiver module and a first interference canceller module. The first receiver module generates a first set of decoded codewords by decoding codewords in a received signal and determines if any of the first set of decoded codewords fails cyclic redundancy check (CRC). The first interference canceller module generates a second signal based on a first decoded codeword from the first set of decoded codewords when (i) any of the first set of decoded codewords fails CRC and (ii) the first decoded codeword passes CRC. By subtracting the second signal from the first signal, the first interference canceller module (i) cancels interference of a first codeword, which corresponds to the first decoded codeword, on a second set of codewords, which includes the plurality of codewords and excludes the first codeword and (ii) generates a third signal, which includes the second set of codewords.

Abstract: To demodulate a quadrature amplitude modulation (QAM) signal, a reception point is determined corresponding to a symbol in the QAM signal that is received where the symbol is mapped to one reference point of a plurality of reference points in a rotated constellation and the plurality of reference points are represented by an in-phase (I) coordinate and a quadrature-phase (Q) coordinate. A plurality of candidate points corresponding to a portion of the plurality of reference points are selected based on distances between the reception point and the respective reference points. The reception point is demapped by calculating a plurality of log-likelihood ratios based on the plurality of candidate points, the plurality of log-likelihood ratios corresponding to bits of data represented by the reception point.

Abstract: In one embodiment of a communications network, the predetermined encoding scheme and symbol constellation configurations are chosen so that the range in channel qualities that the encoding scheme and symbol constellation configurations are designed to be utilized within overlap with each other. This overlapping provides hysteresis, which reduces the frequency with which a subscriber must alter encoding scheme and symbol constellations. Reducing the frequency of changing encoding scheme and/or symbol constellation eliminates the communication overhead associated with these changes and increases throughput by enabling the subscriber to spend more time transmitting data.

Abstract: A method for transmitting a downlink control channel in a mobile communication system and a method for mapping the control channel to physical resources using a block interleaver are provided. In order to transmit a downlink control channel in a mobile communication system, information bits are modulated to generate one or more modulation symbols according to a specific modulation scheme, the modulation symbols are interleaved using a block interleaver, and the interleaved modulated symbols are mapped to resource elements allocated for transmission of at least one control channel in a subframe, thereby transmitting the at least one control channel.

Abstract: The present disclosure relates to multi-mode RF circuitry using a single IQ modulator topology that may support different communication standards, including enhanced data rates for global system for mobile communications evolution (EDGE) and EDGE evolution by dividing certain modulation functions between a frequency synthesizer and an IQ modulator. Specifically, during a standard modulation mode, which may be used to support many communications standards, the frequency synthesizer provides an un-modulated RF carrier signal to the IQ modulator, which either phase modulates or phase and amplitude modulates the un-modulated RF carrier signal to provide a standard modulated RF signal.

Abstract: A method of transmitting data symbols via an Orthogonal Frequency Division Multiplexed (OFDM) symbols that includes forming data symbols into pairs and generating a first pair of modulation symbols for each of the pairs of data symbols, where the first pair of modulation symbols form first and second modulation symbols of an Alamouti cell. The method further includes forming a first version of the OFDM symbols by modulating the sub-carriers allocated for carrying the data with the first and second modulation symbols of the Alamouti cells, and modulating the one or more pilot carriers of the first version of the OFDM symbol according to a predetermined pattern.

Abstract: An apparatus for enabling a base station to transmit radio frequency signals with a transmit diversity technique comprises a first antenna implemented in the base station; and a second antenna implemented in the base station, and placed apart from the first antenna by a predetermined distance. The first antenna utilizes a first frequency band of a predetermined frequency spectrum for transmitting signals, and the second antenna utilizes a second frequency band of the predetermined frequency spectrum for transmitting signals. The first and second frequency bands do not overlap.

Abstract: A method of determining a cell identity in a wireless communication system is disclosed. The present invention includes the steps of obtaining a segment ID and a sequence index from an SA-preamble (secondary advanced preamble) sequence received from a base station and determining the cell identity using the segment ID and the sequence index. In this case, the cell identity corresponds to one SA-preamble sequence and a cell identity adjacent to the cell identity corresponds to an SA-preamble sequence having a complex conjugate relation of the one SA-preamble sequence.

Abstract: A communication system utilizing a hierarchically modulated signal and method thereof are provided, wherein a receiver system is configured to receive a hierarchically modulated signal. The receiver system includes a receiver device configured to receive the hierarchically modulated signal, which is a function of a time domain, and including a high priority data stream that has a single carrier type modulation, and a low priority data stream having data bits that are spread over a plurality of data symbols of a high priority data modulation. The receiver system further includes a low priority processor device, which includes an OFDM decoder configured to convert the low priority data stream of the hierarchically modulated signal that is a function of the time domain to be a function of a frequency domain by utilizing a FFT, such that an output is emitted that is representative of the low priority data stream.

Abstract: A method for uplink power control is described. A user equipment (UE) power class may be determined. An uplink multiple access scheme may also be determined. The maximum transmission power for the UE may further be determined according to the determined uplink multiple access scheme and the UE power class.

Abstract: A modulator and a modulation method for a communication device are disclosed. The modulator is configured to multiplex control symbols and data symbols for transmission in a signal based on information of the distance between the positions of at least two control symbols in a representation of symbol positions in the signal.

Abstract: When transmitting data from a transmission unit to a reception unit over a channel in a wireless communication system, it has been observed that there are inherent losses in throughput, especially for a channel experiencing high channel quality variations over its frequency range. To improve the throughput over such a channel, it is proposed to: estimate the quality of each subchannel of a channel. classify the subchannels into a number of quality groups based on the estimated quality, and select a code rate per quality group. This selected code rate per quality group is then used when a data word to be transmitted is coded. Simulations have shown that by grouping the subchannels into a limited number of groups, for example one to four groups depending on the channel quality variation, a high throughput could be achieved with a minimum of signaling cost in the form of extra overhead.

Abstract: In accordance with the teachings described herein, systems and methods are provided for calibrating DC offset in a receiver. A DC calibration circuit may be used that is configured to receive a digital multi-carrier modulated (MCM) signal that includes a sequence of MCM symbols. The DC calibration circuit may include an accumulator and a compensator. The accumulator may be used to determine an estimated DC offset of a current MCM symbol in the sequence of MCM symbols. The compensator may be used to remove the estimated DC offset from a next MCM symbol in the sequence of MCM symbols. The accumulator may also be used to receive a plurality of digital samples that comprise the current MCM symbol and to determine the estimated DC offset by calculating an average of the plurality of digital samples.

Abstract: A method for transmitting a downlink control channel in a mobile communication system and a method for mapping the control channel to physical resources using a block interleaver are provided. In order to transmit a downlink control channel in a mobile communication system, information bits are modulated to generate one or more modulation symbols according to a specific modulation scheme, the modulation symbols are interleaved using a block interleaver, and the interleaved modulated symbols are mapped to resource elements allocated for transmission of at least one control channel in a subframe, thereby transmitting the at least one control channel.

Abstract: Systems and methodologies are described that facilitate arrangement and transmission of control information in a wireless communication system. As described herein, a scheduled transmission of acknowledgement (ACK) signaling and channel quality information (CQI) signaling in a common subframe can be adapted for network implementations with limited link budget wherein ACK signaling is configured for repetition over multiple subframes to ensure a desired error rate level for the ACK signaling. To these ends, various aspects described herein facilitate modification of a coding rate applied to ACK signaling to be transmitted with data based on a repetition factor of the ACK signaling. Additionally and/or alternatively, various aspects described herein facilitate dropping of CQI signaling and transmission of only ACK signaling on subframes where CQI and ACK signaling are to be transmitted substantially simultaneously and ACK transmission is configured for repetition over multiple subframes.

Abstract: A transmission within a wireless cellular network may include a first and second type of information. A subframe includes a plurality of symbols, at least one symbol is designated as a data symbol and at least one symbol is designated as a reference signal symbol that contains a pre-defined reference signal. The first type of information is embedded in the data symbols. If the second type of data is expected, then the second type of information is embedded in at least one reference symbol by quadrature amplitude modulating the pre-defined reference signal. The subframe is then transmitted from one node in the network to a second node. If it is determined that the second node is not expecting the second type of information, then a discontinuous transmission (DTX) response is embedded in the reference symbol instead of the second type of information.

Abstract: A method and device for the baseband process of space-time/space-frequency/spatial diversity transmitter in the SC-FDMA system, the device is characterized in that: 1) an encoding means is connected to the output end of the M-point DFT module; 2) a space-time encoding means, for encoding the corresponding symbol of at least two adjacent symbol sets, and outputting at least two data sets; each sub-carrier mapping means maps respectively each data set to the corresponding antenna, so that the mapped data satisfy the requirements: The symbols mapped on each antenna keep the same sequence as the M symbols outputted by the M-point DFT module; the mapped symbols keep the same sub-carrier interval; the M data of each mapped SC-FDMA symbol are the M outputted data of the DFT module, or the inverse of the M outputted data, or the complex conjugate of the M outputted data, or the inverse complex conjugate of the M outputted data.

Abstract: An apparatus comprising an artificial noise (AN) controller coupled to a digital subscriber line (DSL) transmitter and configured to adjust an AN level for a signal transmitted by the DSL transmitter, wherein the AN level is adjusted based on an actual signal to noise ratio (SNR) of the signal from the receiver to achieve a desired SNR for the signal. Also disclosed is a method comprising maintaining a data rate in a line at about a desired level by adjusting an AN level in a transmitted signal based on a SNR of a received signal.

Abstract: An apparatus, system, and method may include providing a plurality of data streams in respective subchannels and modulating a first data stream of the plurality of data streams at least partially with a different modulation constellation than a second data stream of the plurality of data streams. The method may also include transmitting the first and second data streams using a same radio resource to user terminals using different subchannels of the radio resource.

Abstract: The present invention relates to digital data communication and provides an efficient method for generating multi-dimensional constellations for digital data modulation with a high degree of modulation diversity, a method for transmitting and receiving data on the basis of such constellations, and a corresponding apparatus. This is achieved by considering only multi-dimensional rotation matrices with all elements on the diagonal having the same first absolute value and all other elements having the same non-zero second absolute value. In this manner, multi-dimensional rotation matrices can be generated having only a single independent parameter and a structure that is as regular as possible. The independent parameter can be configured in order to minimize the error probability for various constellation sizes.

Abstract: A construction is provided for uplink pilot signals in a cellular network. Three sets of pilot signals are defined, having orthogonality properties that lead to reduced inter-cell interference. In example embodiments, the network has a reuse factor of 3 for pilot signals, with sets U, V, and W of pilot signals assigned to cells in respective reuse classes. The pilots of each set form an orthogonal basis. Some pilots of each class, i.e. those which will generally be assigned to mobile stations near the cell edges, will also form an orthogonal basis with some pilots of each of the other classes.

Abstract: Messages transmitted between a receiver and a transmitter are used to maximize a communication data rate. In particular, a multicarrier modulation system uses messages that are sent from the receiver to the transmitter to exchange one or more sets of optimized communication parameters. The transmitter then stores these communication parameters and when transmitting to that particular receiver, the transmitter utilizes the stored parameters in an effort to maximize the data rate to that receiver. Likewise, when the receiver receives packets from that particular transmitter, the receiver can utilize the stored communication parameters for reception.

Abstract: A transmission of information within a wireless cellular network may include a first and second type of information. A subframe is produced that includes a plurality of symbols, wherein at least one symbol is designated as a data symbol and at least one symbol is designated as a reference signal symbol that contains a pre-defined reference signal. The first type of information is embedded in the data symbols. If the second type of data is expected, then the second type of information is embedded in at least one reference symbol by quadrature amplitude modulating the pre-defined reference signal. The subframe is then transmitted from one node in the network to a second node. In some embodiments, if it is determined that the second node is not expecting the second type of information, then a discontinuous transmission (DTX) response is embedded in the reference symbol instead of the second type of information.

Abstract: The communications terminal and acquisition method is for use with Continuous Phase Modulation (CPM) and Phase Shift Keying (PSK) modulation-type signals, each modulation-type signal having a respective preamble phasing sequence. The communications terminal may include a wireless communications device to receive a modulated signal having one of the CPM and PSK modulation types, and having a symbol rate. A controller may be included to cooperate with the wireless communications device to perform a transform process, such as a Fourier Transform (FT) process, on the received modulated signal to detect the modulation type and the symbol rate of the received modulated signal based upon the preamble phasing sequence. Carrier phase and frequency of the received modulated signal may be estimated based upon bin amplitudes. Also, symbol timing may be estimated based upon a phase difference between tones associated with the preamble phasing sequence.

Abstract: A system includes a linked-list generator module that generates a linked list of tones based on tones and bit loads of the respective tones in a digital subscriber line (DSL) communication system, a trellis encoder module that encodes data bits associated with respective ones of the tones, and a bit application module that communicates the data bits to the trellis encoder module based on the linked list.

Abstract: A method and system enables the selective addressing of groups of broadcast receivers within part of a satellite footprint. It uses two satellites having a common transmission band to transmit respective signals, and at receivers in the footprint the phases of the signals received from the two satellites are compared. This phase difference is dependent upon receiver location, but by measuring phase difference no absolute timing or phase measurement is required. A common key is generated at the receivers in a certain area. The output of selected receivers is fed back to the broadcast control centre and is used to encode the location-based services for that area. Preferably the operation is conducted on multiple frequencies and in multiple rounds of such frequencies. A multibit keyword can be directly generated at the receivers by use of a discrete Fourier transform (DFT) and combining its outputs for different rounds.

Abstract: A signal transmitting method, a signal receiving method, and a signal receiving device are adapted to an OFDM system. In the signal transmitting method and signal receiving method, double asymmetric training symbols are used for performing time-varying channel response estimation. In the transmitting method, asymmetric pilot sub-carriers are added in data sub-carriers to form a plurality of first and second training symbols. The pilot symbols in the first and second training symbols are asymmetrically configured. In the receiving method, a channel response corresponding to each pilot sub-carrier is estimated by using two adjacent asymmetric pilot symbols. The received data sub-carrier is then restored through the channel response. Through the signal transmitting method and signal receiving method, even in a transmitter or a receiver moving at a high speed, more bandwidths can be used to transfer data, and contents of the transferred data can be correctly estimated.

Abstract: A control unit generates packet signals to be transmitted. The control unit uses either a first packet format, where a second known signal defined by a second radio communication system different from a first radio communication system is assigned anterior to a first known signal defined by the first radio communication system, or a second packet format, where the first known signal is assigned in an anterior part. Subcarriers to be used in the first known signal contain subcarriers to be used in the second known signal, and the first known signal and the second known signal are defined by different values.

Abstract: Provided are an apparatus and method for generating a soft bit metric and a multi-level (M-ary) Quadrature Amplitude Modulation (QAM) receiving system using the same. The apparatus includes an analog to digital converter for converting an analog symbol signal of a demodulated I (Inphase) or Q (Quadrature) channel into a digital signal, a scaler for scaling the converted digital signal based on a reference value used for determining a space between symbols, a positive integer converter for calculating a positive integer of the scaled digital I or Q channel symbol signal, a sign determinator for determining a sign of the scaled digital I or Q channel symbol signal, and a bit information converter for converting the scaled digital I or Q channel symbol signal into soft bit metric information per bit on the basis of the calculated positive integer and the determined sign value.

Abstract: A system and method are provided for generating bit log likelihood ratio (LLR) values for two-layered Quadrature Phase-Shift Keying (QPSK) turbo decoding in a wireless communications user terminal (UT). The method includes receiving a two-layered QPSK signal with an energy ratio that is unknown, but typically defined as either k12 or k22. The method selects a mismatched energy ratio (k2) between k12 and k22, and generating bit LLR values for two-layered QPSK turbo decoding, using the mismatched k2 energy ratio. For example, if the received two-layered QPSK signal is known to have an energy ratio of about 4 or about 6.25. Then, k2 is selected to be about 5.0625. Alternately stated, the mismatched k2 energy ratio in selected by determining the approximate midpoint between k12 and k22.

Abstract: A mobile communication network includes an antenna site shared by two or more telecommunications service providers. The antenna site includes a shared resource, such as an antenna, telecommunications equipment, or bandwidth, used by multiple service providers and connects to multiple signal processing centers, each of which belongs to one of the service providers. The signal processing centers may provide modulating signals to the antenna site to use in modulating a carrier. The antenna site may also direct received signals from mobile terminals to the signal processing center for the appropriate service provider. A billing module at the antenna site maintains an accounting of resources used by each service provider.

Abstract: A method and apparatus for generating a TSC in a communication system are provided, in which a pair of sequences A and B having auto-correlation and cross-correlation properties are generated and the TSC is generated by inserting guard sequences Z each having z zero symbols in the most significant bits of the sequences A and B.

Abstract: An interleaving method (1) and a frequency interleaver (EF) of data symbols. The data symbols are for allocation to carriers of a set of NFFT carriers of a module for multiplexing and modulation by orthogonal functions in a multicarrier transmitter device (EM). The method includes selecting in time-varying manner from the set of carriers, carriers that are dedicated to transmitting data symbols and in dynamically interleaving a block of carriers constituted by the selected carriers and by null carriers.

Abstract: A physical layer module includes a mapping module and a plurality of gain modules. The mapping module maps a plurality of coded data streams to a plurality of transmit antennas, in which each transmit antenna is associated with a respective radio frequency channel of a plurality of radio frequency channels. Each gain module is associated with a respective radio frequency channel of the plurality of radio frequency channels, and is configured to apply a complex gain to the coded data stream mapped to the respective radio frequency channel associated with the gain module. The complex gain applied by the gain module differs relative to that applied by other gain modules, and corresponds to the transmit antenna associated with the respective radio frequency channel.

Abstract: In one embodiment of a communications network, the predetermined encoding scheme and symbol constellation configurations are chosen so that the range in channel qualities that the encoding scheme and symbol constellation configurations are designed to be utilized within overlap with each other. This overlapping provides hysteresis, which reduces the frequency with which a subscriber must alter encoding scheme and symbol constellations. Reducing the frequency of changing encoding scheme and/or symbol constellation eliminates the communication overhead associated with these changes and increases throughput by enabling the subscriber to spend more time transmitting data.

Abstract: An apparatus and method are disclosed for generating a transmission connection identifier (CID) for a transmitter/receiver pair in a wireless network. The CID may be selected from or mapped to a hybrid CID space comprising a first set of orthogonal CIDs and a second set of non-orthogonal (random or pseudo-random) CIDs. When a transmitter device wants to initiate a peer-to-peer connection with a receiver device, the transmitter and receiver devices attempt to obtain a CID to identify their connection within a traffic channel in a shared frequency space. The first and/or second device attempt to select a CID from the first set of orthogonal CIDs. However, if a CID collision is detected, the first and second devices select their CID from the second set of non-orthogonal CIDs. The selected transmission CID may be used during a time slot or interval to facilitate communications between the first and second devices.

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 wireless communication device includes a converting circuit, a discrete Fourier transformer, a separating circuit, a correcting unit. The converting circuit converts an analog signal having an in-phase component and a quadrature component into a digital signal having a real part and an imaginary part of complex number respectively. The discrete Fourier transformer converts the real part and the imaginary part of the digital signal obtained in the converting circuit from a time domain to a frequency domain. The separating circuit separates the digital signal into a first sum of a symmetrical component of the real part and an antisymmetrical component of the imaginary part of the digital signal and a second sum of the antisymmetrical component of the real part and the symmetrical component of the imaginary part of the digital signal. The correcting unit corrects a value of the second sum.

Abstract: A method for adapting filter cut-off frequencies for the transmission of discrete multitone symbols, where a transmit symbol datastream consisting of discrete multitone symbols is applied to an interpolation device, the transmit symbol datastream is interpolated with a symbol rate in the interpolation device, an interpolated symbol datastream is filtered in a first low-pass filtering device in accordance with a first filter cut-off frequency, which can be predetermined by a first filter cut-off frequency determining device, a digital symbol datastream obtained after a digital-analog conversion, transmission and analog-digital conversion, is filtered at the receiver end in a second low-pass filtering device in accordance with a second filter cut-off frequency, which can be predetermined by a second filter cut-off frequency determining device, in order to provide an equalized symbol datastream, the equalized symbol datastream is decimated in a decimation device and the decimated received symbol datastream consi

Abstract: A multipoint-to-point, orthogonal frequency division multiplexed (OFDM) communication system is provided. The system includes a plurality of remote units and a host unit that includes a demodulator. Each of the remote units transmits an upstream OFDM signal using a multiple access scheme to the host unit demodulator using at least one of a plurality of orthogonal tones within an OFDM waveform. The host unit receives the upstream OFDM signals from a plurality of the remote units. Portions of upstream OFDM signals from at least two of the remote units arrive at the host unit at the same time. The host unit demodulator demodulates the portions and the upstream signals from the plurality of remote units arrive at the host unit synchronized in time and frequency within the OFDM waveform.

Abstract: A method, system and apparatus using hybrid automatic repeat-request (HARQ) to enhance a system throughput in a transmit diversity system.

Abstract: Provided is an apparatus and method for detecting a packet in a Wireless Local Area Network (WLAN) which can reduce a processing time of packet detection based on Orthogonal Frequency Division Multiplexing (OFDM) by detecting a received packet employing symmetry of a short preamble. The packet detecting apparatus includes an autocorrelation average power calculation unit for calculating an absolute value of an autocorrelation average power value obtained by delaying a preamble signal of a received signal by half of a preamble length, an average power calculation unit for calculating an average power value of the received signal, a power ratio calculation unit for calculating a ratio of the average power value to the absolute value of the average power value, and a packet detection unit for detecting the packet by using the power ratio calculated by the power ratio calculation unit.

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 of transmitting pilot signals in a system which performs communication using two or more earners comprises transmitting first pilots and second pilots from at least one user equipment to a base station, the first and second pilots, which are transmitted from the at least one user equipment, being multiplexed by code division multiplexing, and the first and second pilots, which are transmitted from a specific user equipment, having different transmission powers, and transmitting data from the at least one user equipment to the base station depending on the first pilots and the second pilots. Since many UEs can transmit CQ pilots, exact channel estimation can be performed and thus communication efficiency can be improved.

Abstract: A software correlator comprising: a partitioning module adapted to divide a number of the received data samples into a first number of data blocks; a first correlation module adapted to correlate each of the data blocks with a respective local code replica segment to produce a first number of intermediate accumulation results; an aggregation module adapted to combine a number of consecutive results of the intermediate accumulation results into a target number of aggregated accumulation results, the target number expresses a number of discrete carrier values in a carrier vector that represents a Doppler shift of the at least one spread spectrum source signal relative to a downconverting frequency for this signal; and a second correlation module adapted to correlate the aggregated accumulation results with the carrier vector to produce the decoded signal, which is compensated for the Doppler shift relative to the downconverting frequency.

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: System and method for providing multiple access in a multi-band, orthogonal frequency division multiplexed (multi-band-OFDM) communications system. A preferred embodiment comprises determining a transmission bandwidth to support a performance requirement and configuring transmission bands in the multi-band-OFDM communications system based upon the transmission bandwidth, wherein the transmission bands may be made up of smaller transmission bands bonded together. Further comprising initializing communications with the configured transmission bands. The use of bonded transmission bands can provide increased data rates and/or increased range performance.