Abstract: An OFDM-CDMA transmission apparatus may include a first spreader that carries out spreading processing on a plurality of transmission signals using different spreading codes, respectively. A second spreader carries out spreading processing on at least one known signal using a spreading code different from the spreading codes employed by the first spreader. A frequency division multiplexer breaks down the transmission signals spread by the first spreader and the known signal spread by the second spreader into individual chips and subjects these chips to frequency division multiplexing, thereby assigning one chip data signal string per subcarrier. The frequency division multiplexer operates such that information from each of the plurality of transmission signals and the known signal is multiplexed into every chip assigned to a different subcarrier. After the chips are assigned to the subcarriers, they are transmitted by a transmitter.

Abstract: The orthogonal frequency division multiplexing (OFDM) method is well-known for transmitting data on electrical power supply lines. According to this method, the items of information to be transmitted are distributed among numerous carriers, and the composite signal of the modulated carrier signals is transmitted in the form of an OFDM block. Standard OFDM methods are, however, highly sensitive to strong periodic pulse jammers. According to the invention, the method is thus devised such that the OFDM blocks to be transmitted have a length of approximately 85% of the interval between two periodic disturbing pulses. The carrier interval accordingly results from the reciprocal duration of the OFDM blocks. The transmitted OFDM blocks are synchronized with pulse-shaped periodic jammers in such a manner that one block at a time is located between two disturbing pulses. The pulse-shaped jammers can be gated at the receiver.

Abstract: A transmitting/receiving apparatus includes a packet construction section for dividing continuous data into a plurality of subpackets, and constructing a packet by concatenating the plurality of subpackets; a modulation transmission section for modulating the constructed packet, and transmitting the modulated packet to another apparatus; a training session execution section for checking channel conditions, when a predetermined condition is satisfied, and changing a modulation rule; and a subpacket transmission confirmation section for confirming whether or not a subpacket included in the transmitted packet is transmitted successfully to the transmission destination apparatus.

Abstract: To address the need for reducing pilot overhead, a method and apparatus for transmitting and receiving data is provided herein. A communication system having a transmitter (100) that utilizes adaptive modulation and coding (AMC) and utilizes lower-order modulated (e.g., QPSK) data as a substitute for pilot symbols during transmission. Data intended for a user utilizing a lower order modulation can be reliably detected, and if properly processed, used as pilots for a user that is trying to receive a higher order modulation (e.g., 64-QAM). Because lower order modulated data is utilized for pilots, fewer overall pilots are used. This greatly reduces pilot overhead, increasing data throughput.

Abstract: A transmitter for optical communication systems includes a source of optical radiation, a source of complex non-information signals, and a modulator unit in communication with the source of optical radiation. The modulator unit is also in communication with the source of complex non-information signals. The modulator has an input adapted to receive information-bearing signals.

Abstract: A transmission antenna diversity method, and a base station apparatus and a mobile station apparatus therefor in a mobile communication system are provided. In the transmission antenna diversity method, channel information is measured from signals received through the plurality of antennas used in the base station, and a channel information matrix is output. The channel information matrix is transformed according to a transform matrix composed of a complex basis vector set. Reception power with respect to the plurality of antennas is calculated based on the transformed channel information matrix. Antenna selection information obtained based on the calculated reception power is transmitted to the base station as feedback information for controlling transmission antenna diversity. Therefore, power is equally distributed to transmitting antennas, excellent performance is maintained at a high speed of movement, and reliable channel adaptation is accomplished at a low speed of movement of the mobile station.

Abstract: A receiver for generating a transmission symbol stream by applying predetermined modulation processing to an encoded bit series obtained by encoding an information bit series having a predetermined transmission rate. The receiver generates a transmission-information bit series having a transmission rate lower than a predetermined transmission rate in accordance with an information bit series and receives a transmission signal generated in accordance with the transmission-information bit series through a communication channel. The receiver stepwise increases the low transmission rate of the transmission-information bit series to reach a predetermined transmission rate by stepwise increasing the low transmission rate, while stepwise increasing the number of communication channels to be used in accordance with the stepwise increase of the low transmission rate.

Abstract: A system and method for enhancing the data rate of a WLAN. Through the deployment of a MIMO system, the data rate ordinarily expected of a SISO type system can be doubled. Yet, the MIMO system of the present invention can remain backward compatible with conventional WLAN standards implemented by typical SISO type system. In particular, the packet preamble of the MIMO packet of the present invention is similar to that of a conventional SISO system so as to be backward compatible with conventional SISO receivers. Additionally, the data model of the MIMO system can be configured to support the detection of symbols in the MIMO packet of the present invention. Importantly, the present invention can include a least squares soft-detector for use in a wireless LAN compatible MIMO system.

Abstract: A method and apparatus are provided for error correction in a communication system employing Orthogonal Frequency Division Multiplexing. When a remote unit receives an OFDM symbol, a retransmission indicator bit is examined to determine whether the symbol is an original symbol or a retransmitted symbol. If it is a retransmitted symbol and the remote unit has a corresponding symbol stored in memory, then the received symbol is soft-combined with the stored symbol. Each packet in the symbol, either the received symbol if original or the soft-combined symbol if retransmitted, is examined by the remote unit. If the remote unit determines that a particular packet is intended for the remote unit, but can not determine the contents of the payload of the packet, the remote unit sends a retransmission request to the base station for retransmission of the symbol.

Abstract: An orthogonal frequency division multiplexed signal transmitting apparatus executes a time-division multiplexing process that inserts a reference signal at a predetermined interval based on reference signal position information into an information signal to be transmitted. The transmitting apparatus generates an orthogonal frequency division multiplexed signal by digital-modulating the time-division multiplexed signal to radiate into a spatial transmission line. An orthogonal frequency division multiplexed signal receiving apparatus receives the signal from the transmitting apparatus to get the reference signal by demodulating the signal.

Abstract: A system for bidirectional communication of digital data between a central unit and a remote unit wherein the need for tracking loops in the central unit has been eliminated. The central unit transmitter generates a master carrier and a master clock signal which are used to transmit downstream data to the remote units. The remote units recover the master carrier and master clock and synchronize local oscillators in each remote unit to these master carrier and master clock signals to generate reference carrier and clock signals for use by the remote unit receiver. These reference carrier and clock signals are also used by the remote unit transmitters to transmit upstream data to the central unit. The central unit receiver detects the phase difference between the reference carrier and clock signals from the remote units periodically and adjusts the phase of the master carrier and master clock signals for use by the central unit receiver to receive the upstream data.

Abstract: A communication device for receiving and transmitting OFDM signals in a wireless communication system, in which each OFDM signal is composed of a plurality of subcarrier signals each being assigned to a respective transmission channel. The device includes a diversity antenna, examination mechanism adapted for examining, individually for each antenna element, at least one subcarrier signal of an OFDM reception signal received by a respective one of the antenna elements and for gaining, from the result of such subcarrier signal examination, attenuation information on attenuation properties of at least some of the transmission channels associated with the respective antenna element and an amplitude adjustment mechanism adapted for adjusting, individually for each antenna element, the amplitude of at least one subcarrier signal of an OFDM transmission signal to be transmitted from a respective one of said antenna elements in accordance with said attenuation information.

Abstract: By embedding as a Physical Layer (PHY) Appliqué patterns (time, frequency, tone multiplexed, control signal, explicit network authentication, projective, other, or combined) on wireless electronic communications network (WECN) digital signal packets, and using a QRD-based auto-SCORE adaptation algorithm to maximize the signal-to-interference-and-noise ratio (SINR) attainable by multielement arrays over very small time-bandwidth products, differentiation and detection of signals from environmental noise (particularly from other or non-network signals) can be improved, allowing more compressed, secure, efficient network operations.

Abstract: In a radio signal transmitter, a microcomputer operates by receiving an output voltage of a battery to sequentially generate a voltage boosting control signal. This voltage boosting control signal has a longer high level period as generated later. The voltage booster circuit boosts the output voltage of the battery by increasing the number of times of oscillating operations during the high level period of the voltage boosting control signal depending on the increased high level period.

Abstract: An orthogonal wavelet division multiplexing (OWDM) communication system including a synthesis section and a channel interface. The synthesis section includes a filter pair bank with multiple inputs and an output that provides an OWDM signal. Each input receives a corresponding symbol of a supersymbol, where the symbols are from a selected modulation scheme. The synthesis section generates the OWDM signal as a combination of weighted OWDM pulses, where each weighted OWDM pulse represents of a symbol of the supersymbol. An OWDM Spread Spectrum (OWSS) communication system that uses broad-time and broadband pulses generated from a family of OWDM pulses together with a set of orthogonal PN code vectors. The OWSS pulses are mutually orthogonal and allow multi-user operation. Each user is assigned an OWSS pulse corresponding to a particular PN code. OWSS enables high rate operation for wireless channels with the use of an equalizer with FE and DFE sections.

Abstract: A high speed Bluetooth system with switch-to quadrature amplitude modulation allows for simple mobile devices with video data rates in applications such as Internet downloading. Mobile devices may have multiple antennas and adaptive hopping frequencies.

Abstract: A method is provided for defining a pulse function shape for acting on a data stream for transmission in a telecommunication system in accordance with a predetermined modulation scheme. The method comprises defining desired cost parameters (e.g., error functions for amplitude, BER, bandwidth, energy, AFC) and defining the shape of the pulse function in dependence of the desired cost parameters. A pulse generator, modulator and communications device using such a defined device are also provided. Application in dual mode TDMA/CDMA system.

Abstract: A composite signal has two components, each carrying a stream of information that may be digital. In one application of a method according to an embodiment of the invention, at least one of the components is delayed such that a time relation between the streams of information is altered. The components are transferred via a common signal path such that upon transfer, the original time relation between the streams of information may be restored.

Abstract: The present invention provides a unique feedback system in a wireless communication system wherein the transmission channel is always overloaded with data, which is configured and modulated at a select order of modulation. Based on the channel conditions, only a portion of the data can be successfully received. As such, the receiver will attempt to receive the data using demodulation techniques corresponding to the different levels of modulation used to encode the data transmitted. The receiver will determine the data that is recovered, or the highest order of modulation at which the data is recovered, and provide feedback to the transmitter. The transmitter will then retransmit the data that was not properly received. By overloading the channel at all times, the maximum amount of data capable of being transmitted over the channel is optimized without requiring or heavily relying on the receiver feeding back channel condition information to the transmitter.

Abstract: The aim of the invention is to process OFDM signals which are simultaneously received via a multiple antenna system having a plurality of separate receive channels. To this end, the channel correction values or the confidence values are determined in the receive channels for each carrier of the OFDM signal while using known techniques. In addition, the I/Q values of each individual carrier of the OFDM signal which are obtained in the OFDM demodulator are weighted with these channel correction values or confidence values. Afterwards, the I/Q values weighted in such a manner are totaled.

Abstract: A baseband signal multiplexing circuit controls an amplitude level of a baseband signal to be transmitted on the basis of the number of transmission codes. A gain set value is calculated with which an amplitude value of the baseband signal outputted from a level adjustment circuit is adjusted to an amplitude value matching a dynamic range of a D/A converter based on transmission code number information transmitted from a signal processor. The level adjusting circuit is notified of the gain set value with a control signal.

Abstract: A method for retransmitting coded bits by a transmitter in response to a retransmission request from a receiver in a mobile communication system which separates coded bits output from an encoder into coded bits with higher priority and coded bits with lower priority, and transmits from the transmitter to the receiver a stream of symbols obtained by symbol mapping the coded bits by a specific modulation technique. The method comprises determining orthogonal codes available for retransmission; separating the coded bits with higher priority and the coded bits with lower priority into a plurality of sub-packets with a given size, and selecting a part of the sub-packets or sub-packets to be repeatedly transmitted, depending on the determined number of available orthogonal codes; and transmitting a stream of symbols obtained by symbol-mapping coded bits of the selected sub-packets by the specific modulation technique, with the determined available orthogonal codes.

Abstract: Disclosed is a method for providing first and second interleaved bit streams to a modulator in order to transmit the first and second interleaved bit streams through at least two antennas in a mobile communication system. An encoder encodes a transmission data stream into a first bit stream with first priority and a second bit stream with second priority being lower than the first priority. An interleaver interleaves the first and second bit streams into the first and second interleaved bit streams. The modulator modulates the first and second interleaved bit streams.

Abstract: Apparatus, and an associated method, for forming a space-generated multilevel coding scheme for a radio communication system. Two or more modulators are positioned at a sending station. The modulators modulate, pursuant to separate modulation schemes, data that is to be communicated by the sending station. The modulation schemes are lower-order modulation schemes. The modulated data is communicated to a receiving station, and detected at a least single receive antenna. The modulated symbols formed by the separate modulators are superimposed theretogether and form symbols of a higher order modulation scheme.

Abstract: Methods and systems for communicating on a wireless channel are provided which enable subscribers that share the channel to transmit using different modulation schemes. The modulation scheme used by each subscriber is assigned to the subscriber by a wireless access termination system. The modulation scheme assigned to a subscriber by the wireless access termination system is determined based on measurements of the quality of signals received from that subscriber. In one embodiment, the invention includes a transmitter and a receiver. The receiver is capable of transmitting data using one of a number of encoding and symbol constellation configurations. The receiver is also capable of receiving a first signal. Receiving the first signal causes the transmitter to transmit a second signal using a specified encoding and symbol constellation configuration.

Abstract: Disclosed is an OFDM communications system and a method of operating the OFDM communications system. The system includes an OFDM transmitter for transmitting data over a plurality of OFDM sub-channels, where the OFDM transmitter has a plurality of modulators of different types. The system further includes an OFDM receiver for receiving the data from the plurality of OFDM sub-channels, where the OFDM receiver has a plurality of corresponding demodulators of the different types. The system further includes, in accordance with this invention, an adaptive learning automata that contains a group or team of independent, decentralized automaton operating in accordance with a game theory-based approach. Each of the plurality of automaton are responsible for managing one MCS switching threshold value so as to maximize at least one selected performance criterion.

Abstract: A system is described which provides bidirectional transport of data at different data rates for each direction over a shared medium. In one embodiment, the different data rates are accomplished using different modulation techniques. For example, in the downstream direction, quadrature amplitude modulation (QAM) 64 is used and in the upstream direction orthogonal frequency division multiplexing (OFDM) is used. The QAM 64 modulation provides for a higher number of bits per hertz in a transmission channel. By using QAM 64 modulation, down stream transmission rates on the order of 30 megabits per second (Mbps) in a 6 MHz channel can be achieved. A number of 6 MHz channels can be combined to provide for even higher data rates.

Abstract: The invention relates to a device for aiding the analysis of signals by using symbols-based digital modulation. The device includes a signal memory for storing a complex digital signal, representative in amplitude and phase of a captured signal, over a chosen duration, as well as a processor for searching for the properties relating to the carrier frequency of the complex signal and to its modulation. According to the invention, the processor includes a projector for calculating the components of the complex signal in a function basis, the function basis being parameterized according to an estimated tempo of the modulation, as well as a calculator, operating on these components so as to determine an estimate relating to a property of the complex signal, from among its elementary pulse shape, the string of symbols of the complex signal and its carrier.

Abstract: A transmitting apparatus, receiving apparatus, communication system, and a signal processing method for each apply a suitable modulation method and transmission path estimation method in accordance with the characteristics of the transmission information and capable of improving the transmission efficiency. At the transmission side, the method of estimation of the transmission path and the modulation method are selected in accordance with an attribute of the data to be transmitted, for example, the size of a packet to be transmitted, the transmission data is mapped by the selected modulation method, the signal is processed in accordance with the transmission path estimation method, and a transmission signal is created by increase fast Fourier transform processing and transmitted.

Abstract: A transmitting apparatus, receiving apparatus, communication system, and a signal processing method for each apply a suitable modulation method and transmission path estimation method in accordance with the characteristics of the transmission information and capable of improving the transmission efficiency. At the transmission side, the method of estimation of the transmission path and the modulation method are selected in accordance with an attribute of the data to be transmitted, for example, the size of a packet to be transmitted, the transmission data is mapped by the selected modulation method, the signal is processed in accordance with the transmission path estimation method, and a transmission signal is created by increase fast Fourier transform processing and transmitted.

Abstract: A method and apparatus of communicating information using Time Division Multiple Access and adaptive transmission and reception are disclosed. Signal bursts are transmitted from TDMA transmitters to a TDMA receiver wherein the transmitter codes the information and transmits coded information to the receiver using at least one of two timeslots of a plurality of timeslots in a repetitive TDMA frame period. Both of the two timeslots are received whether or not the transmitter has transmitted using one or two timeslots and the received signals are classified as intended and non-intended. Successively received signals classified as intended are then assembled into a block for decoding to reproduce the information.

Abstract: A method for bi-directional data synchronization between different clock frequencies is described wherein a state machine counter is provided a first clock signal having a first frequency. The state machine counter is then provided a second clock signal having a second frequency that is an integer multiple of the first clock frequency. The state machine counter has an integer number of states equivalent to the ratio of the second clock signal frequency to the first clock signal frequency. The first clock signal is applied to reset the state machine counter to an initial state. The state machine counter generates an intermediate clock signal whenever the state machine increments through all states to return to the initial state. The intermediate clock is then applied to synchronize data between the first clock frequency and the second clock frequency.

Abstract: In comb-form spectrum communication systems using repeated complementary sequence modulation, a transmitting signal is constituted by assigning one set of N auto-complementary sequences to each user, where N is an integer equal to or higher than 2, and by transforming the N sequences to N repeated signals which have comb-form spectra without overlapping in frequency with one another with a method of repeating each sequence of the set of auto-complementary sequences a plurality of times, and by assigning the N complementary sequences with auto-complementary sequence characteristics to the N comb-form spectra. Thus, the near-far problem is solved by making the cross-correlation between a signal input to a user's station but addressed to another station and the user's reference code sequence, zero.

Abstract: An apparatus and method for phase modulating SYNC codes transmitted over downlink pilot time slots DwPTSs when a primary common control physical channel P-CCPCH is transmitted using transmit diversity in an NB-TDD CDMA mobile communication system. The apparatus and method transmits and receives the P-CCPCH signal using the transmit diversity by providing a diversity indicator for changing phase variation of the SYNC codes included in the DwPTSs.

Abstract: Systems and methods for sharing a single decoder among data streams originating with multiple sources. Error correction coding techniques are modified to facilitate decoding of data from multiple sources multiplexed in the time domain at the decoder input. A single decoder accommodates multiple sources that have been encoded using disparate code rates. One application is an OFDM point to multipoint system.

Abstract: A dual modulation transmitter apparatus (100) includes first (134), second (136), and third (132) signal paths. The first signal path includes a polar modulator (120) coupled to a data input (115). The second signal path includes a quadrature modulator (122) coupled to the data input. The third signal path is coupled to an antenna (142) and includes a switch (128) configured to couple the third signal path to the first signal path under a first condition and to couple the third signal path to the second signal path under a second condition. Thus, the transmitter apparatus enjoys the best of both worlds, since it utilizes quadrature or polar modulation in the most appropriate circumstances.

Abstract: The invention is a process and system for controlling selection of which MS is to receive the next packet data transmission on a forward channel and selection of which plural MCS is to be used for the packet data transmissions on the forward channel. A process for controlling selection of MCS method to be used by a BTS (10) to transmit data packets over a forward shared channel to a MS (12) in accordance with the invention stores information at the BTS, the information containing MCS methods which may be selected to transmit data packets over the forward shared channel to the MS; receiving from the MS at the BTS a quality indication of transmission of data packets over the forward channel to the MS; and selecting a MCS method from a plurality of MCS methods which may be used to transmit data packets on the forward channel dependent upon the received quality indication.

Abstract: A transmitting apparatus, receiving apparatus, communication system, and a signal processing method of each applying a suitable modulation method and transmission path estimation method in accordance with characteristics of the transmission information for improving the transmission efficiency operate so that at the transmission side, the ratio of adding transmission path estimation pilot symbols is suitably controlled in accordance with an aspect of the dat transmitted, for example, the size of the packets transmitted and the state of the transmission path, wherein the transmission data is mapped by the selected modulation method, and the signal is processed in accordance with the method of estimation of the transmission path, and the transmission signal is produced by inverse fast Fourier transform processing and transmitted.

Abstract: A transmitting apparatus, receiving apparatus, communication system, and a signal processing method for each apply a suitable modulation method and transmission path estimation method in accordance with the characteristics of the transmission information and capable of improving the transmission efficiency. At the transmission side, the method of estimation of the transmission path and the modulation method are selected in accordance with an attribute of the data to be transmitted, for example, the size of a packet to be transmitted, the transmission data is mapped by the selected modulation method, the signal is processed in accordance with the transmission path estimation method, and a transmission signal is created by increase fast Fourier transform processing and transmitted.

Abstract: An apparatus for detecting the signals of transmission diversity based on space-time coding is disclosed. The apparatus and method for detecting signals of space-time coding performs linear interpolation and linear filtering to calculate the channel estimate of each transmission symbol from the channel estimate of each slot, thus providing the correct channel estimate even in a channel with considerable fluctuation. Further, the output control with estimation of SIR only passes a proper output of the demodulating and detecting circuit to improve the signal to noise ratio, maintaining enough communication quality even in a bad communication environment.

Abstract: A multi-protocol modulator capable of supporting two or more different modes of operation, each mode of operation corresponding to a different type of modulation, comprises an m-level phase shift keying (m-PSK) modulator which receives a serial input data stream and maps data contained therein into a constellation including m equidistant phases in accordance with a predetermined mapping scheme. The m-PSK modulator is shared by at least two different modulation protocols by allowing the mapping scheme to be selectively changed depending upon the modulation protocol used. The multi-protocol modulator further includes a phase rotator operatively coupled to the output of the m-PSK modulator. The phase rotator selectively rotates the phase of the m-PSK signal by a predetermined phase rotation value. The phase rotator is shared by the two or more modulation protocols by allowing the phase rotation value to be selectively modified depending upon the modulation protocol used.

Abstract: A system and method for enhancing the data rate of a WLAN. Through the deployment of a MIMO system, the data rate ordinarily expected of a SISO type system can be doubled. Yet, the MIMO system of the present invention can remain backward compatible with conventional WLAN standards implemented by typical SISO type system. In particular, the packet preamble of the MIMO packet of the present invention is similar to that of a conventional SISO system so as to be backward compatible with conventional SISO receivers. Additionally, the data model of the MIMO system can be configured to support the detection of symbols in the MIMO packet of the present invention. Importantly, the present invention can include a least squares soft-detector for use in a wireless LAN compatible MIMO system.

Abstract: The invention relates to a method and to a modulator for modulating signals. The signals are to be transmitted by a device in packets via an air interface. Each packet is supposed to comprise at least one entity of at least two different entities, which different entities are employed for transmitting signals representing different kinds of information. In order to enable a higher data rate, signals that are to be transmitted in at least one of said different entities are modulated with a first set of values of at least one modulation parameter of a selected modulation scheme. Further, signals that are to be transmitted in at least one other of said different entities are modulated with a second set of values of said at least one modulation parameter, said second set of values comprising less values than said first set of values.

Abstract: A method for channel response estimation for an OFDM communication system based on a certain normal training symbols plus one virtual training symbol begins with receiving at least one preamble symbol of a transmitted data frame. A first channel state information is estimated from the at least one preamble symbol. At least one signalling symbol is then received and equalized and a rate factor and a length factor are extracted from the at least one signalling symbol. A virtual training symbol is formed from the rate factor and the length factor. A second channel state information is estimated from the at least one preamble symbol and the virtual training symbol. The data symbols are equalized by performing channel correction on data symbols with the second channel estimation and pilot sub-carriers in each of the plurality of data symbols.

Abstract: A method of mode detection for an OFDM signal. The method comprises the steps of a) selecting one of the desired symbol lengths, b) selecting one of the threshold values, c) generating a correlation power signal of the OFDM signal using the selected desired symbol length, d) detecting edges of the correlation power signal using the selected threshold value, e) when the edge detection succeeds, determining the transmission mode and guard interval length by the detected edges, and f) when the edge detection fails, determining whether all the threshold values have been selected, if so, selecting another one of the desired symbol lengths and repeating steps b, c, d, e and f, otherwise, selecting another one of the threshold values and repeating steps c, d, e and f.

Abstract: Orthogonal frequency division multiplexing (OFDM) transmitting and receiving apparatus and methods can extend a communication distance by duplicated transmission of symbols in multiple channels. An input OFDM data bitstream is encoded to generate a symbol stream. The symbol stream is copied into multiple symbol streams and converted into data complex symbol streams by a modulation method. An input pilot bitstream is converted into a pilot complex symbol stream, and the pilot complex symbol stream is inserted into the data complex symbol streams to generate transmission symbol streams. Fast Fourier transform (FFT) processing of the transmission symbol streams is performed. Guard intervals (GIs) are inserted into the FFT processed signals. The signals are converted into analog signals, loaded onto carriers and transmitted.

Abstract: The present invention relates to a method of reducing a peak-to-average power ratio of a signal to be transmitted. The method comprises the steps of detecting a portion of the signal being above a clipping threshold level, decomposing the portion of the signal into a number of functions, the number of functions being proportional to a duration of the portion of the signal, performing the number of soft-clippings on the signal by means of a reference function, the positions of the soft-clippings being given by the positions of the functions and the respective scalings of the reference function being determined by the amplitudes of the functions.

Abstract: The present invention relates to a method for modulating a signal in a system providing short-range wireless communication. In the signal, the signal is transmitted in packet format, in which each packet comprises at least a first part and a second part. In the method, the first part and the second part are modulated by using the first modulation method and the second modulation method, respectively. The second modulation method is initialized by using the first part. The invention also relates to a transceiver device and a wireless communication system, in which the method is applied.

Abstract: The present invention provides a method of operation for a variable transmission mode multi-carrier communication system by receiving a signal, determining a link quality as a function of the received signal, and selecting a compound multi-carrier communication mode as a function of the link quality.

Abstract: The present invention makes it possible to perform channel estimation and delay profile detection based on not only an dedicated physical channel (DPCH) but also a common channel signal (e.g., downlink shared channel (DSCH)), and can thereby implement a radio reception apparatus capable of performing channel estimation and creation of a delay profile with a high degree of accuracy.