Abstract: An apparatus and operation method of a Mobile Station (MS) for ranging in a broadband wireless access communication system includes receiving information for ranging code hopping from a Base Station (BS). The MS determines a hopping offset value that is a start of a ranging codes group using the information for ranging code hopping. The MS also determines a ranging codes group using the hopping offset value, and randomly selects at least one or more ranging codes among the determined ranging codes group and transmitting the selected ranging codes to the BS.

Abstract: A transmitting apparatus and receiving apparatus of a multi-carrier system using multiple antennas is proposed. A linear complex field (LCF) encoder performs linear precoding of input signals to be transmitted using a linear complex matrix based on the number of antennas and the number of subcarriers, and a subcarrier allocator allocates a subcarrier to each precoded signal. A transmitter transmits the signals through the multiple antennas. In a receiving apparatus, a subcarrier de-allocator extracts a linear-precoded signal by de-allocating a subcarrier of the received signal, and an LCF decoder outputs a bit reliability of the received signal based on the number m of antennas and the number n of subcarriers. Performance may be improved by using space diversity using multiple antennas and frequency diversity using OFDMA, and system complexity may be reduced by using a lattice reduction and a 2-branch Chase decoder.

Abstract: A method for terminal-assisted interference control in a mobile communication system employing multi-carrier techniques such as OFDM, the mobile communication system comprising a network with a plurality of base stations controlled by a central entity, and the base stations having means for communication with user terminals located inside their cell service area, wherein the central entity schedules time-frequency groups available, for data communication purposes between the terminals and the base station, for the base stations under its control and the terminals involved in the scheduling process, each time interval.

Abstract: Angle estimation for modulated signal. A novel compensation technique is presented by which angle estimation may be performed for a modulated signal. More specifically, the angle between a constellation corresponding to a received signal and a constellation corresponding to a received signal may be very efficiently estimated using any one of the possible embodiments corresponding to various aspects of the invention. After this angle has been estimated, the received signal or the expected constellation may be rotated (or de-rotated) to compensate for this angular difference. In doing so, better estimates of the information bits that are demodulated and decoded from the received signal may be made.

Abstract: A method and apparatus for transmitting a preamble for frame synchronization and channel estimation in a MIMO-OFDM communication system are provided. An OFDM communication system using Q transmit antennas generates a base preamble sequence including a CP and an orthogonal sequence. If Q?a predetermined number M, a preamble sequence for a kth antenna is S(t?(k?1)T/M). If Q>M and k?M, the preamble sequence transmitted for the kth antenna is S(t?(k?1)T/M). If Q>M and k>M, the preamble sequence for the kth antenna is (?1)(PS-1)S(t?(k?M?1)T/M). Here, S(t) is the orthogonal sequence, T is the period of the orthogonal sequence, and PS is an index indicating a transmission period of the preamble sequence. The preamble sequences are at least twice transmitted from the Q transmit antennas.

Abstract: A technique for generating a Single-Carrier Frequency Division Multiple Access (SC-FDMA) signal based on a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence is disclosed. A method embodiment of this technique comprises generating a frequency domain representation of the CAZAC sequence by providing an analytical representation of the CAZAC sequence in the frequency domain with an integer phase term and calculating the integer phase term in a recursive manner for each of a plurality of frequency domain samples of the CAZAC sequence. The resulting frequency domain representation of the CAZAC sequence is then mapped to a predetermined frequency location before being transformed into the time domain to obtain a time domain representation of the SC-FDMA signal. The SC-FDMA signal may be a random access signal for transmission on a Physical Random Access Channel (PRACH).

Abstract: A method and apparatus of transmitting a reference signal in a wireless communication system is provided. A reference signal sequence is generated by using a pseudo-random sequence. A portion or entirety of the reference signal sequence is mapped to at least one resource block and is transmitted. The pseudo-random sequence is generated by a gold sequence generator which is initialized with initial values obtained by using cell identifier. The reference signal provides low PAPR and high cross correlation characteristic.

Abstract: Certain embodiments of the present disclosure propose a technique that may be utilized to accelerate the processing of MAC management messages by an MS, allowing the MS to return to a lower power state sooner, thereby conserving power. An indication of whether or not data bursts in a downlink (DL) sub-frame contain MAC management messages may allow the MS to avoid needlessly processing of data bursts and return to a low power state sooner.

Abstract: Channel state information for closed-loop transmit precoding in MIMO networks is fed back from the MSs to the BSs. The feedback is quantized using codebooks shared by the MSs and BSs to reduce overhead. The codebooks can be full-rank or rank-one. The quantized feedback is applicable to any definitions of MIMO channel covariance matrix as well as MIMO channel matrix. Since these codebooks are designed for closed-loop MIMO precoded transmissions, no additional memory is needed to store the codebooks at the BS and the MS only for the quantized feedback purposes.

Abstract: An apparatus and method for simultaneously providing service to users each having a different number of antennas in a multiple-antenna wireless communication system are provided. The communication method discloses a BS in a wireless communication system that services a first multiple antenna mode using X transmit antennas and a second multiple antenna mode using Y transmit antennas such that (Y>X), the BS determines an MS to be serviced in the second multiple antenna mode and receives a sounding signal from the MS. The BS estimates an uplink channel using the received sounding signal and acquires downlink channel values using estimated uplink channel values. Then the BS services the MS in the second multiple antenna mode using the downlink channel values.

Abstract: Disclosed is a downlink signal configuring method and device, and synchronization and cell search method and device using the same in a mobile communication system. A downlink frame has plural symbols into which pilot subcarriers are distributively arranged with respect to time and frequency axes. Initial symbol synchronization and initial frequency synchronization are estimated by using a position at which autocorrelation of a cyclic prefix of a downlink signal and a valid symbol of the downlink is maximized, and cell search and integer-times frequency synchronization are estimated by using pilot subcarriers included in the estimated symbol. Fine symbol synchronization, fine frequency synchronization, and downlink frame synchronization is estimated by using an estimated cell search result.

Abstract: Embodiments described herein include methods for improving the SINR, and therefore communication quality or rate, in the downlink of a cellular communication system. In an embodiment, the system is an orthogonal-frequency-division multiple-access (OFDMA) system. In an embodiment, a set of terminals is designated a coordinated-transmission group. The set of terminal is chosen such that the slot-allocations of the set are given special treatment to alleviate interference from other sectors or cells. In an embodiment, “zones” defined in the WiMax standard are “repurposed” to handle the coordinated-transmission, although the zone was originally intended for another purpose.

Abstract: A method and apparatus for de-interleaving interleaved data in a deinterleaver memory in an Orthogonal Frequency Division Multiplexing (OFDM) based Integrated Services Digital Broadcasting Terrestrial (ISDB-T) receiver. In different embodiments, the apparatus comprises of a OFDM symbol counter along with a divider or a buffer pointer RAM with circular pointer logic, a first lookup table to obtain delay buffer size and interleaving lengths for a given OFDM transmission layer, and a second lookup table to obtain buffer base address and interleaving lengths for a given OFDM transmission layer.

Abstract: A method of transmitting OFDM signals including, allocating a first pilot signal and a first data signal which are both common among OFDM transmitters respectively to at least one first pilot subcarrier and first data subcarriers within a specific time-frequency domain that is common among the OFDM transmitters and different among wireless transmitting units, allocating a second pilot signal and a second data signal respectively to second pilot subcarrier and second data subcarriers outside the time-frequency domain, multiplying the first pilot signal and the first data signal by a complex number set for the time-frequency domain, generating an OFDM signal by performing OFDM modulation on the first pilot signal and the first data signal multiplied by the complex number and the second pilot signal and the second data signal, and transmitting the OFDM signal.

Abstract: A method of configuring a data packet including an orthogonal frequency division multiplexing (OFDM) preamble in a wireless communication system is disclosed. The method includes configuring the data packet to include the OFDM preamble in a first region, a pilot and medium access control (MAC) in a second region, and a data symbol in a third region.

Abstract: In a communication device for receiving signals from devices that become communication partners, received signals from the respective devices are identified. Each of the devices that become communication partners is provided with a frequency spectrum of a pattern specific to each of the devices. The communication device stores correspondence between information identifying the devices that become communication partners and the frequency spectrums provided to the respective devices, acquires a frequency spectrum contained in a received signal, compares the frequency spectrum acquired with the frequency spectrums stored to identify a device corresponding to the frequency spectrum that coincides with the frequency spectrum acquired and which is stored.

Abstract: A system for communicating includes a transmitter that has an encoder and baseband modulator that encodes and modulates a sequence of data symbols as a payload data constellation to be communicated. A PN sequence generator and baseband modulator form a pilot signal as a training sequence with a periodically repeating spread spectrum sequence. A circuit superimposes the pilot signal over the sequence of data symbols to form a composite communication signal that is transmitted. A receiver receives the composite communication signal and extracts the pilot signal from the composite communication signal.

Abstract: Estimation of channel characteristics and interference level in a time-varying multi-carrier multi-user systems is carried out concurrently. To perform the estimation, a multitude of data symbols and dedicated pilot symbols are transmitted over the channel. The estimate of the interference level is used to estimate the channel parameters.

Abstract: Provided are an apparatus and method for transmitting/receiving a pilot code pattern used to identify a base station. In the base station, a pilot code pattern determiner determines a code set that includes a number of spreading codes based on a specific ID of the base station. A first spreader spreads a pilot symbol mapped onto an FC with a corresponding spreading code according to the determined code set, and controls gain so as to transmit the pilot symbol at a higher signal level than data. A second spreader spreads data symbols mapped onto the FC with spreading codes of the code set except for the spreading code used for the pilot spreading. A mapper groups a spread signal from the first spreader and spread signals from the second spreader on a TFC basis, and outputs signals that constitute each TFC to points of sub-carriers. An IFFT unit performs an IFFT operation on signals output from the mapper. Because the pilot as well as the data is spread, it is easy to implement the base station.

Abstract: Embodiments of the invention relate to a method of generating digital multi-carrier frequency division multiplexing (FDM) signals, the signals comprising FDM symbols having pilot symbols, wherein at least one FDM symbol has pilot symbols which are non-equidistantly spaced in frequency. Other embodiments of the invention relate to a method of processing multi-carrier frequency division multiplexing (FDM) signals, the method comprising the following steps: a) demodulating digital multi-carrier FDM signals, said signals being comprised of FDM symbols having pilot symbols, the pilot symbols of at least one FDM symbol being non-equidistantly spaced in frequency, b) replacing, on a sub-carrier basis, at least one data symbol with a pilot symbol, whereby the replacement yields a spacing of pilot symbols which is equidistant in frequency for all FDM symbols.

Abstract: A method for providing two or more broadcast services in an orthogonal frequency division multiple access (OFDMA) wireless communication system. The method comprises the steps of separately receiving broadcast services to be transmitted, and independently performing coding, interleaving and modulation on the broadcast services according to a required quality for each of the broadcast services; segmenting each of the modulated broadcast signals into minimum transmission units; time-division-multiplexing the segmented broadcast service signals; configuring a frame comprising information on the broadcast service in physical layer transmission information transmitted together with the broadcast service; and transmitting the frame.

Abstract: A multiple-access communications downlink uses OFDM and error-correcting codes to send data to multiple terminals from a single access point, in which packets of message information for multiple users are aggregated and encoded into a single error-correction codeword, in which assigned time slots corresponding to specific OFDM symbols are used to separate different users, so that a near-capacity achieving channel coding system constructs a single codeword for use with iterative decoding architectures at the mobile terminals.

Abstract: A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.

Abstract: A method of generating a code sequence in a wireless communication system is disclosed. More specifically, the method includes recognizing a desired length of the code sequence, generating a code sequence having a length different from the desired length, and modifying the length of the generated code sequence to equal the desired length. Here, the step of modifying includes discarding at least one element of the generated code sequence or inserting at least one null element to the generated code sequence.

Abstract: In this invention, we propose a near maximum likelihood (ML) method for the decoding of multiple input multiple output systems. By employing the metric-first search method, Schnorr-Euchner enumeration, and branch length thresholds in a single frame systematically, the proposed technique provides a higher efficiency than other conventional near ML decoding schemes. From simulation results, it is confirmed that the proposed method has lower computational complexity than other near ML decoders while maintaining the bit error rate (BER) very close to the ML performance. The proposed method in addition possesses the capability of allowing flexible tradeoffs between the computational complexity and BER performance.

Abstract: A modulator, and more particularly an HPSK modulator, is disclosed that enables the circuit scale to be reduced and also enables power consumption to be reduced. An HPSK modulator 209 incorporated in a radio communication apparatus or the like is equipped with a spreading code multiplication section 11, a complex arithmetic section 101, a coefficient determination section 51, and raised COS filters 41 and 42. Spreading code multiplication section 11 multiplies transmit data DPDCH1 by a spreading code Cd1. Complex arithmetic section 101 performs complex arithmetic on an output signal output from spreading code multiplication section 11 and a scrambling code Sn, and performs conversion to complex data. Coefficient determination section 51 determines a filter coefficient Ad1n based on a gain factor ?d1 that determines transmission power. Raised COS filters 41 and 42 band-limit the complex data using the filter coefficient.

Abstract: This invention is concerned with a transmission control method and apparatus in a collision interval for a collision of multidimensional hopping patterns. In the present invention, each orthogonal wireless resource in the coordinate of the multidimensional orthogonal resource can hop according to the hopping pattern negotiated between a transmitter and a receiver, and each corresponding channel is distinguished by the hopping pattern. A specific multidimensional hopping pattern is allocated to each secondary station. The hopping pattern is either permanently allocated to the secondary stations or temporarily allocated from the primary station during a call set-up. The permanent allocation of the hopping pattern to the secondary stations is achieved when the hopping pattern is identified based on a unique identifier, such as ESN of the secondary station.

Abstract: Disclosed are a method, information processing system and wireless communications device for suppressing interference. The method includes receiving a transmission from each of a target (104) and interfering device (106). A set of pilot sequences (604) for an interfering device (106) and the target device (104) are determined. A channel estimate (608) for the target device (104) and the interfering device (106) is determined. A set of combining weights (610) associated with each pilot sequence for the interfering device (106) is determined as a function of the determined channel estimates (608) of the target device (104) and the interfering device (106). At least one pilot symbol estimate (612) for each pilot sequence in the set of pilot sequences for the interfering device is determined as a function of the received transmission and the determined set of combining weights (610).

Abstract: A multiple stream cyclic-shifted delay transmitter including a baseband processing module and a plurality of RF transmit sections. The baseband processing module is operably coupled to convert outbound data into a plurality of transmit baseband signal streams and cyclic-shift delay at least one of the plurality of transmit baseband signal streams to produce at least one cyclic shift delayed transmit baseband signal stream. The plurality of RF) transmit sections is operably coupled to convert the plurality of transmit baseband signal streams and the at least one cyclic-shift delayed transmit baseband signal stream into a plurality of RF signals.

Abstract: A method and apparatus of transmitting control information in a wireless communication system is provided. A sequence corresponding to control information from a sequence set is determined. A reference modulation symbol set corresponding to a mini unit by modulating the sequence is generated. At least one reordered modulation symbol set is generated by reordering and repeating the reference modulation symbol set. The at least one reordered modulation symbol set is reordered in a unit of a subgroup. The reference modulation symbol set and the at least one reordered modulation symbol set are mapped to the plurality of mini units in the resource unit respectively.

Abstract: A method of transmitting and receiving data using superposition modulation in a wireless communication system having multiple antennas is disclosed. More specifically, the method comprises encoding the at least one inputted data stream by a channel coding scheme, puncturing the at least one inputted coded data stream into at least two sub-streams, layer-modulating the at least two sub-streams using layer-modulation schemes, transmitting the layered-modulated sub-streams via the multiple antennas, wherein transmission power of each antenna is based channel condition, and receiving by at least one user the layered-modulated sub-stream, wherein the each user uses different demodulation scheme.

Abstract: In a high-speed search system for CDMA, plural (M) symbols which are subjected to spread frequency coding with a spreading code called as a short code are prepared when synchronization of the spreading code is established before synchronization of carrier is established in a mobile station used in a CDMA cellular system, data which are obtained by forming an orthogonal code with the polarities of the M symbols are set as a down signal, and when the orthogonal code concerned is detected, coherent integration is performed by a correlator having combinations of the polarities which can be possibly taken by the code over the plural symbols (of M) constituting the code.

Abstract: An apparatus and method for measuring noise in a reception apparatus of a wireless communication system supporting Orthogonal Frequency Division Multiplexing (OFDM). The apparatus and method converts a preamble signal of a received OFDM frame into a frequency domain, and measures signal strength at each of subcarriers to which a null signal is allocated, from the preamble signal converted into the frequency domain. Further, the apparatus and method determines signal strength caused by noise depending on an average of signal strengths measured at the subcarriers. The preamble signal includes multiple subcarrier signals, and the subcarrier to which a null signal is allocated is a subcarrier over which no signal is transmitted by the transmission apparatus.

Abstract: Systems and techniques are disclosed relating to communications. The systems and techniques involve communicating over a physical channel having a plurality of modulation channels each having a channel capacity by allocating a plurality of data streams among the modulation channels as a function of the channel capacity for each of the modulation channels, and modulating the data streams to support transmission over the physical channel as a function of the data stream allocation among the modulation channels. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: An Orthogonal Frequency Division Multiplexing, OFDM, transmitter comprises a signalling data generator (113) which generates a set of data symbols indicative of physical layer characteristics of data transmissions from the OFDM transmitter (100). A first symbol generator (115) and second symbol generator (117) generates a first and second OFDM signalling symbol by allocating the set of data symbols to subcarriers. The allocation of the physical layer data symbols to subcarriers is different for the first OFDM signalling symbol and the second OFDM signalling symbol. A data packet generator (105) and transmitter (101) generate a data packet and transmit this to an OFDM receiver (300). The OFDM receiver (300) determines the physical layer data symbols by combining the data symbols of corresponding subcarriers of the first and second OFDM signalling symbols and uses the resulting information to decode the user data of the data packet.

Abstract: Dynamic and asymmetric sub-channel allocation in a wireless communications system—particularly an orthogonal frequency division multiple access (OFDMA) system—is disclosed. The methods and constructs of the present disclosure identify a plurality of cells, each divided into an equal number of sectors. A transmission channel associated with each cell is divided into a plurality of sub-channel groups. For each sector, a set of adjoining inter and intra coverage area sectors is identified, and associated together as a pool set. For each such pool set, a resource pool is formed from the plurality of sub-channel groups. A single sub-channel group from a resource pool is allocated to each sector in a corresponding pool set. Additional sub-channel group in that resource pool are thereafter allocated to sectors from the pool set on an as-needed, as-available basis.

Abstract: Disclosed is a method for controlling downlink power transmitted from a base station to subscriber stations in a mobile communication system employing an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, in which data is carried from the base station to the subscriber stations by subchannels to each of which a plurality of subcarriers are assigned. The method includes the steps of receiving from the subscriber stations channel condition information of each of the subchannels together with information related to a subcarrier having a channel condition below a threshold from among at least one subcarrier included in each of the subchannels; calculating transmission power for each of the subchannels based on the received information; and transmitting each of the subchannels with the calculated transmission power, excluding the subcarrier having a channel condition below the threshold.

Abstract: Inter-carrier interference (ICI) in a kth sub-carrier of an orthogonal frequency division multiplexing (OFDM) signal received at time t is reduced, wherein the received OFDM signal comprises a plurality of sub-carriers. This is achieved by generating a self-interference term, ICIk?L,k?L, for a signal received on sub-carrier k?L, wherein L ? [ . . . , ?3,?2,?1,1,2,3, . . . ], and wherein the self-interference term is an estimate of the data received at time t on the sub-carrier k?L, weighted by a rate of change of the channel through which sub-carrier k?L passes at time t. An ICI cancellation coefficient, GL is obtained, and an estimated ICI term is generated by adjusting the self-interference term, ICIk?L,k?L, by an amount based on the ICI cancellation coefficient, GL. The estimated ICI term is then subtracted from a term representing a signal received on the kth sub-carrier at time t.

Abstract: Embodiments described herein include methods for improving the SINR, and therefore communication quality or rate, in the downlink of a cellular communication system. In an embodiment, the system is an orthogonal-frequency-division multiple-access (OFDMA) system. In an embodiment, a set of terminals is designated a coordinated-transmission group. The set of terminal is chosen such that the slot-allocations of the set are given special treatment to alleviate interference from other sectors or cells. All terminals within a coordination group generally use the same slot, but embodiments are not so limited.

Abstract: Pilots are transmitted on demand on a reverse link and used for channel estimation and data transmission on a forward link. A base station selects at least one terminal for on-demand pilot transmission on the reverse link. Each selected terminal is a candidate for receiving data transmission on the forward link. The base station assigns each selected terminal with a time-frequency allocation, which may be for a wideband pilot, a narrowband pilot, or some other type of pilot. The base station receives and processes on-demand pilot transmission from each selected terminal and derives a channel estimate for the terminal based on the received pilot transmission. The base station may schedule terminals for data transmission on the forward link based on the channel estimates for all selected terminals. The base station may also process data (e.g., perform beamforming or eigensteering) for transmission to each scheduled terminal based on its channel estimate.

Abstract: In a communication system, when packet data units (PDUs) to be transmitted from a transmitter apparatus are modulated according to Orthogonal Frequency Division Multiplexing (OFDM), the waveforms representing the modulated PDUs will experience different peak to average ratio values (PAR) making the PDUs differently sensitive to non-ideal transmitter characteristics. To minimize errors in the transmitted PDUs, at least two PDUs (304, 305, 306) are scrambled and modulated in parallel and substantially simultaneously in the transmitter (100), and the PAR values of the at least two PDUs (304, 305, 306) are determined at each transmit instance. The measured PAR values of the at least two PDUs are compared in a scheduler (310), and the scheduler selects for transmission the PDU with the lowest PAR value. The scheduler (310) then instructs the transmitter (100) to transmit the selected PDU.

Abstract: In the system acquisition process system information is non-coherently detected using correlation of reconstructed and received preamble signals, such as the primary broadcast control channel (PBCCH) and the acquisition pilots (TDM1, TDM2, and TDM3). The phase correlation signals between the correlated signals of PBCCH and TDM2 or TDM3 and between the correlated signals of TDM2 and TDM3 are combined to decode other sector interference (OSI) information and the like. Acquisition is also made more efficient by taking advantage of predictable information based on system synchronicity. The sync/async bit is included in at least one of the acquisition pilots. The mobile then uses knowledge of system synchronicity to more efficiently detect the additional information in the superframe preamble.

Abstract: An arrangement is disclosed where in a multi-carrier communication system, the modulation scheme, coding attributes, training pilots, and signal power may be adjusted to adapt to channel conditions in order to maximize the overall system capacity and spectral efficiency without wasting radio resources or compromising error probability performance.

Abstract: An improved method is provided for reducing inter-carrier interference in the CDMA subchannels of hybrid OFDMA-CDMA systems. The results of decoding OFDMA tones are used to at least partially cancel interference from CDMA tones. Then, the CDMA tones are decoded. In specific embodiments, control information is obtained by an initial step of decoding the CDMA tones. The control information is used in decoding the OFDMA tones. Then, the decoding of the OFDMA tones and the decoding of the CDMA tones are performed iteratively, such that at least one instance of OFDMA decoding is used to cancel interference from the CDMA tones, and at least one instance of CDMA decoding is used to obtain improved control information for decoding the OFDMA tones.

Abstract: Method and embodiments in a multipath wireless communication system employing a wireless frame having alternating cyclic prefixes to reduce inter-symbol interference (ISI) are presented herein.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent sub-carriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent subcarriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.

Abstract: A signal scrambling method is provided for peak-to-average power ratio (PAPR) reduction of STBC MIMO-OFDM signals in a MIMO-OFDM system having Y transmit antenna. In general terms the OFDM sequence of symbols in said signal for each transmit antenna is divided into M sub-blocks of equal size and subclockwise subblockwise rotation and inversions are performed across all transmit antennas to generate [2Y]M permuted sequence sets from the original OFDM sequence. Based on a predetermined criteria, there is then selected from the resulting sets of OFDM sequences the one with the best PAPR properties for transmission. The predetermined criteria preferably comprises identifying maximums for all [2Y]M sequence sets, by calculating the largest PAPR value of Y sequences in each set and selecting a set with the minimum maximum for transmission.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent subcarriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.

Abstract: The present invention proposes a method for generating synchronization bursts for OFDM transmission systems. The symbols of a predefined symbol sequence are mapped according to a predefined mapping scheme on subcarriers of the OFDM systems by a mapping unit (2), wherein the symbols of the predefined symbol sequence represent subcarriers of the OFDM system with nonzero amplitudes. A synchronization burst is generated by a inverse fast Fourier transforming unit (3) transforming the subcarriers of the OFDM system mapped to said predefined symbol sequence. The mapping (2) of the symbols of the predefined symbol sequence is set such that the resulting time domain signal of the synchronization burst represents a periodic nature. According to the invention the predefined symbol sequence is set such that the envelope fluctuation of the time domain signal of the synchronization burst is minimized. Therefore advantageous symbol sequences reducing said the envelope fluctuation of the time domain signal are proposed.