Abstract: Optical correlators are discussed, suitable for in-vehicle distance measurement. The correlators use modulation sequences based on maximal length sequences. A number of different modulation sequences are obtained by generator (32) from a single maximal length sequence, either by adding a variable number of cycles to the end of the maximal length sequence or by starting the maximal length sequence at different points in the sequence.

Abstract: Allocation of multiple training sequences transmitted in a MIMO timeslot from multiple transmit antenna elements is provided. For example, a method of generating signals in a MIMO timeslot, the method comprising: selecting a first training sequence; preparing a first data payload; generating a first signal including the prepared first data payload and the first training sequence; transmitting the first signal in a MIMO timeslot from a first antenna of a network element; selecting a second training sequence, wherein the second training sequence is different from first training sequence; preparing a second data payload; generating a second signal including the prepared second data payload and the second training sequence; and transmitting the second signal in the MIMO timeslot from a second antenna of the network element.

Abstract: An embodiment for wirelessly communicating a signal includes a transmitter generating and transmitting a wireless signal over a wireless communication channel. The wireless signal includes a guard band, data represented within a plurality of data-bearing subcarriers, and a plurality of pilot signals represented within a plurality of pilot subcarriers. In an embodiment, the plurality of pilot signals have variable pilot signal parameters selected from a group of parameters that includes pilot power and pilot spacing with respect to adjacent pilots. An embodiment further includes a receiver receiving a channel-affected version of the wireless signal, and producing a corrected signal by applying corrections to the received signal based on estimated channel perturbations within the received signal, where the estimated channel perturbations are determined based on the plurality of pilot signals. The receiver also produces an output data symbol from the corrected signal.

Abstract: In a pilot signal transmission method for raising the SIR measurement accuracy for transmission power control during high-speed transmission and thus reducing the block error rate and improving the throughput, a first SIR value measured by first pilot signals and second SIR value measured by second pilot signals are first compared, and the presence or absence of second pilot signals then determined in slot units based on the comparison results. When the second pilot signals exist, the second pilot signals are used in addition to the first pilot signals in the SIR measurement for high-speed closed-loop transmission power control. When the second pilot signals do not exist, only the first pilot signals are used in the SIR measurement for high-speed closed-loop transmission power control.

Abstract: OFDM synchronization and signal channel estimation is accomplished by adding pilot signals to the outputs of OFDM encoders, i.e. after encoding of data/symbols, in a spread spectrum wireless communication system utilizing uniquely designed OFDM transmitters, OFDM receivers and OFDM systems and methods.

Abstract: A communication device includes a transmitter and a receiver. The transmitter includes a transmission-side code generator and a first spread unit for example. The receiver includes a reception-side code generator and a first inverse spread unit for example. The transmission-side code generator generates a spread code comprised of a spread code scheduled according to a difference of a transmission cycle of an input signal. The first spread unit performs spread spectrum processing on the input signal by the spread code. The reception-side code generator generates a spread code in use for performing inverse spread spectrum processing on a receiving signal. The first inverse spread unit performs inverse spread spectrum processing on the receiving signal by the spread signal generated at the code generator.

Abstract: Interference of multiplexed signals is reduced in an MC-CDMA communication system. A wireless communication apparatus performing a wireless communication by combining a multicarrier transmission system with a spread spectrum includes: a rearrangement control part that ranks each subcarrier in accordance with a magnitude of received power based on received power information indicating received power of each subcarrier received from a communicating apparatus and groups subcarriers in descending or ascending order of the rank in accordance with a spreading factor; and a rearrangement part that distributes a spread code to each of the groups.

Abstract: An electronic apparatus with power saving functionality is disclosed. The electronic apparatus has a first signal processing circuit and a second signal processing circuit. The first signal processing circuit includes a receiver logic for receiving at least a signal; and a power saving determination logic for monitoring an operation status of the receiver logic and generating a first control signal according to the operation status. The second signal processing circuit includes a processing logic for receiving the received signal from the receiver logic and processing the received signal; and a power saving trigger logic for controlling the processing logic to enter a power saving mode from a normal mode when receiving the first control signal from the power saving control logic.

Abstract: Communication performance is to be improved in a communication system in which a plurality of wireless communication lines share space. A transmitting device 2 transmits a transmission signal to a base station 6 a plurality of number of times. The base station 6 updates a weight wk to be used for an FIR filter, generates a hopping pattern Pk to be used by the transmitting device 2 for generating a transmission signal, adjusts the hopping pattern Pk so as to suppress a peak-to-average ratio (PAR) occurring in the transmission signal to generate a hopping pattern P?k, quantizes the hopping pattern P?k, and transmits the quantized hopping pattern P?k to the transmitting device 2. The transmitting device 2 uses the hopping pattern P?k received from the base station 6 in subsequent spread spectrum to generate a transmission signal.

Abstract: The present invention is provided with a wireless transceiver and wireless transmitting/receiving method and program thereof capable of improving the robustness against Doppler frequency by containing transmit diversity signals in one spreading region. In the present invention, the transmitter encodes the transmit signals using a space-time matrix and transmits the encoded space-time signals after being spread with different spreading codes, and the receiver de-spreads the received spread signals, in unit of time slot, with the spreading codes corresponding to the respective time slots and then decodes the de-spread signals using the space-time matrix.

Abstract: One embodiment of the invention provides a method of creating a set of secondary spreading codes for use in a satellite navigation system comprising a constellation of satellites. Each satellite in the constellation employs a tiered spreading code comprising at least a primary code and a secondary code. Each satellite in the constellation is allocated a different secondary spreading code from the set of secondary spreading codes. The method involves generating an initial set of bit patterns, where each bit pattern represents a potential secondary spreading code. The method further involves performing an optimization process on bit patterns within the initial set of bit patterns. As a result of the optimization, at least some of the bit patterns in the initial set are modified or replaced, to create a final set of bit patterns for use as the set of secondary spreading codes.

Abstract: Provided is a high frequency radio apparatus for correcting a frequency of a carrier of the own apparatus in accordance with a frequency of a reception carrier when performing spread spectrum communication using very weak power. A carrier demodulating part demodulates a spread code received from a communication counterpart radio apparatus by using default carrier data, and sends the demodulated spread code to a synchronization timing detecting part. When the synchronization timing detecting part detects the spread code from the carrier demodulated data, a carrier frequency deviation detecting part performs a frequency analysis of the spread code to detect a deviation amount of the carrier frequency. A carrier data generating part generates corrected carrier data based on the detected deviation amount. A DBPSK modulating part uses the corrected carrier data to perform data transmission to the communication counterpart radio apparatus.

Abstract: Allocation of multiple training sequences transmitted in a MIMO timeslot from multiple transmit antenna elements is provided. For example, a method of generating signals in a MIMO timeslot, the method comprising: selecting a first training sequence; preparing a first data payload; generating a first signal including the prepared first data payload and the first training sequence; transmitting the first signal in a MIMO timeslot from a first antenna of a network element; selecting a second training sequence, wherein the second training sequence is different from first training sequence; preparing a second data payload; generating a second signal including the prepared second data payload and the second training sequence; and transmitting the second signal in the MIMO timeslot from a second antenna of the network element.

Abstract: A transmitter suppresses peak power occurring in a transmission signal. The transmitter generates peak suppression signals for suppressing the peak power in the transmission signal respectively, synthesizes the peak suppression signals generated, and subtracts a signal as a synthesis result from the transmission signal.

Abstract: A method and system for processing communication signals is provided and may comprise, minimizing a cost function in a MIMO pre-coding system by choosing a smallest scalar cost from a plurality of scalar costs, wherein each one of the scalar costs is generated from one or more sums and one or more products of elements of a product matrix, and wherein the product matrix is generated from one of the plurality of unitary matrices, a matrix comprising the channel estimate, and their respective Hermitian Transposes. The codebook is selected based on the minimized cost function. The channel estimate is quantized onto the selected codebook.

Abstract: A spread spectrum communication system includes a first and a second antenna, a first and a second radio frequency demodulator, a first and a second analog-to-digital converter, a first and a second filter, a clear channel assessment device, and a selection device. The radio frequency demodulators convert radio frequency signals to baseband signals, respectively. The analog-to-digital converters convert baseband signals to digital signals, respectively. The filters filter the first and second digital signals to generate filtered signals, respectively. The clear channel assessment device generates a channel assessment signal and a path selection signal according to signal characteristics of the filtered signals. The selection device refers to at least one of the channel assessment signal and path selection signal to selectively output one of the filtered signals, or generate no signal output.

Abstract: A method of embedding information within a burst carrier signal, the method comprising modulating meta-data using a modulator such that a meta-carrier signal results, lowering a Power Spectral Density (PSD) of the meta-carrier signal by Direct Sequence Spread Spectrum (DSSS) chipping the meta-carrier signal using a linear Pseudo-Random Number (PRN) sequence, embedding one or more modulated symbols of the meta-carrier signal within an unused portion of one or more quadrants of a modulation constellation of a burst carrier signal such that a composite carrier signal results, and synchronously transmitting the composite carrier signal using a transmitter such that symbols of the meta-carrier signal are synchronized with symbols of the burst carrier signal.

Abstract: At least a portion of a total spectrum bandwidth of a wireless system may be allocated to each of a plurality of users by assigning at least one unique spreading code to each of the plurality of users. At least two of the plurality of users may have different spectrum capabilities and may transmit simultaneously. Each of the assigned spreading codes may have a different code length. The number and/or the code length of the spreading codes assigned to each user may be indicative of a portion of the total spectrum bandwidth allocated to each user.

Abstract: A radio transmitting apparatus wherein unnecessary consumption of transmission power can be suppressed and PAPR (Peak to Average Power Ratio) can be reduced in multicarrier communication. In the apparatus, a repetition part (105) replicates (repeats) each symbol outputted from a modulating part (103) to generate and output a plurality of identical symbols to an S/P part (107), which converts the symbol sequence outputted in series from the repetition part (105) into parallel symbol sequences and outputs them to an interleaver (109). The interleaver (109) then reorders the symbol sequences outputted from the S/P part (107) and outputs them to a mapping part (111), which removes, in accordance with the propagation path quality of each of subcarriers constituting OFDM symbols that are multicarrier signals, some of the identical symbols as replicated by the repetition part (105) and then maps the rest of the symbols onto subcarriers for application to an IFFT part (113).

Abstract: Systems and methods are disclosed for processing at least two spread spectrum signals that at least partially overlap in time and in frequency. A main correlator bank with a trip detection component can determine a PN code phase for each of the spread spectrum signals that are associated with a PN code signal. The signals may at least partially overlap in time and in frequency. The PN code phases can be determined by comparing the signals to internally generated PN code phases. Based on the comparison, trips associated with the code phases are detected. The PN code phase for each signal can be used to extract a data signal from the signal. The data signals can be outputted.

Abstract: A disclosed signal transmitting method includes the steps of a) categorizing plural digital signals, obtained by performing A/D conversion on plural analog signals consecutively arranged in a time direction, into plural signal groups in an order starting from lower bits of the plural digital signals, b) performing code spreading on the plural digital signals by using a different spread frequency for each signal group and using different spread codes for each bit, c) multiplexing the spread digital signals, and d) transmitting the multiplexed plural digital signals.

Abstract: A transmitting apparatus for transmitting digital data includes storage unit for storing a digital data delay due to digital processing inside the transmitting apparatus; and delay information transmitting unit for transmitting delay information indicating the delay stored in the storage unit.

Abstract: A frequency synthesizer is described illustrating a method for modulation having an adjustable standard curve used to modulate an input signal for spread spectrum modulation. In particular, the a standard curve is generated, wherein the standard curve modulates an input signal to generate a spread spectrum of frequencies. The standard curve is associated with a standard modulation frequency. The standard curve is sampled at a constant sampling frequency. A shape of the standard curve is adjusted, such that critical points of the standard curve are captured when sampling the standard curve. The shape of said standard curve that is altered varies between at least two periods.

Abstract: An electric wave receiving apparatus comprises: an antenna; an amplifier; filter circuits that extract signals in different frequency bands from an output of the amplifier; detector circuits that demodulate time codes from outputs of the filter circuits; automatic gain control circuits that generate gain control signals from the detector circuits; a selector that selects one gain control signal indicating a maximum signal level among the gain control signals; and an arithmetic processing section to be able to analyze the time codes of outputs of the plurality of detector circuits, wherein the one gain control signal is supplied to the amplifier to control an amplification factor of the amplifier so that signal levels output from detector circuits do not become excessive, and the arithmetic processing section selects an output to enable the analysis of the time code among the outputs of detector circuits to perform the analysis of the time code.

Abstract: A flexible, reconfigurable, power efficient transmitter device and method is provided. In one embodiment, the method includes receiving outbound data and determining a mode of operation. When operating in a first mode the method may include modulation mapping the outbound data according a modulation scheme to provide first modulation mapped digital data, converting the first modulation mapped digital data to an analog signal that comprises an intermediate frequency (IF) analog signal, upconverting the IF analog signal to produce a first modulated radio frequency (RF) signal based on a local oscillator signal, amplifying the first RF modulated signal to produce a first RF output signal, and outputting the first RF output signal via an isolator.

Abstract: An apparatus and a method for transmitting/receiving data generate main service data of broadcasting data, generate additional data of the broadcasting data, transform the additional data into a parallel type, generate pseudo-random noise sequences as a spreading code of the additional data, select polarities of the pseudo-random noise sequences using any one additional data bits in the additional data in the transformed parallel type, map the remaining additional data bits excluding the one additional data bit from the additional data in the transformed parallel type to a single sequence, multiply a single sequence to which the remaining additional data bits are mapped by pseudo-noise sequences of which the polarities are selected, control mean power of the additional data multiplied by the sequences, couple the additional data of which the mean power is controlled with the main service data, and then, transmit the broadcasting data.

Abstract: A transmitting device includes a setting unit dividing a transmitting frequency bandwidth into frequency blocks each narrower than a receivable bandwidth of a receiving device, and setting a transmission rate in each of the frequency blocks so as to increase or decrease stepwise, and a receiving device receiving signal with the transmission rate being thus set includes a receiving unit receiving the signal in any one of a plurality of receiving segments falling within the transmitting frequency bandwidth, each having the receivable bandwidth and provided so that at least one of the frequency blocks included in each receiving segment is also included in at least one of other receiving segments.

Abstract: A transmitter and a method are described herein that generate a reduced peak-to-rms ratio multicode radio signal which helps to conserve battery life and increase the communication range and average data throughput rate.

Abstract: An ultra-wideband pulse Doppler radar employing a transform domain communication system class of output waveform, a waveform additionally modified for enhanced radar usage. The achieved waveform includes sequential radar output pulse discrimination, improved pulse repetition frequency range ambiguity, phase modulation generating a noise-like output signal appearance and improved resolution characteristics. The invention employs radar waveform shaping in the frequency domain according to a sample of present operating band interference conditions followed by transformation into the time domain for fabricating an output pulse waveform. Mathematical basis for the improved output waveform and correlation comparisons in graphical form are included in the disclosure.

Abstract: A system and method for generating a spread spectrum clock signal with a constant ppm offset as a function of a repetition number. A phase interpolator can be configured in association with of a phase-locked loop circuit in order to provide a phase movement from a bit clock generated by the PLL circuit. A repetition number divider computes the repetition number for each time slot in a piece-wise SSC modulation profile. A noise shaping modulator can be employed for modulating a fractional part associated with the repetition number. A repetition counter and a phase accumulator receives an integer part of the repetition number and counts unit interval clock periods equal to a sum of integer and the sigma-delta modulated fractional parts of the repetition number. The phase accumulator can be incremented and/or decremented based on the sign of the spread spectrum direction.

Abstract: To suppress deterioration of retransmission efficiency and retransmit a transmission signal efficiently even when the system bandwidth is extended, provided are a base station apparatus (20) which divides, in a retransmission block dividing section (21), a transmission signal into retransmission blocks according to a retransmission block table in which the number of the retransmission blocks each of which is a retransmission unit of a transmission signal is increased corresponding to the number of transmission antennas and registered, and retransmits in downlink transmission signals associated with the divided retransmission blocks, and a mobile terminal apparatus (10) which receives the transmission signals associated with the retransmission blocks from the base station apparatus (20), and combines the retransmission blocks to restore the transmission signal prior to division.

Abstract: A UWB transmitting/receiving apparatus, a UWB transmitting/receiving terminal apparatus and a UWB transmitting/receiving system wherein a possibly reduced number of data retransmissions is achieved so as to raise the transmission efficiency. A UWB transmitting/receiving apparatus (100), which performs a UWB transmission, comprises a receiving part (400) that receives a propagation environment determination pulse transmitted from a UWB transmitting/receiving terminal apparatus (200), which also performs a UWB transmission, and a transmitting part (300) that transmits a data signal while the receiving part (400) is receiving the propagation environment determination pulse.

Abstract: A method of processing data comprises the receiving a frame of data having a predetermined number of time slots (502,504,506). Each time slot comprises a respective plurality of data symbols (520). The method further comprises a primary (508), a secondary (510) and a tertiary (512) synchronization code in each said predetermined number of time slots.

Abstract: An improved method is provided for positioning a directional antenna coupled to a radio towards a satellite. The method includes: receiving an input to the radio from an operator of the radio, where the input indicates a desired time period for positioning the antenna; transmitting, during the desired time period, a plurality of burst data transmissions from the radio over a channel associated with the satellite; receiving a plurality of reply data transmissions from the satellite which correspond to the plurality of burst data transmissions sent by the radio; determining a metric indicative of signal quality for each of the reply data transmissions; and outputting from the radio an indicator for each metric. The operator of the radio can use the indicator output by the radio to better position the antenna towards the satellite.

Abstract: It is an object of the present invention to hold the detecting range of a timing correlator in a base station to the minimum required and to reduce the circuit scale and power requirement of the timing correlator. Before a mobile station transmits a data signal, it transmits a signal referred to as a preamble signal to measure the transmission timing to the base station. If the base station detects the preamble signal with a timing correlator having a limited circuit scale, then the base station transmits a transmission permission signal to the mobile station. If the mobile station fails to receive the transmission permission signal over a given period of time after it has transmitted the preamble signal, then the mobile station retransmits the preamble signal at a changed transmission timing based on the received electric power of a control signal transmitted continuously from the base station and information included in the control signal.

Abstract: Method and apparatus for determining a transmission configuration for a dedicated channel in a wireless communication system. In one embodiment, an optimum configuration is determined based on minimizing Peak-to-Average Ratio (PAR) of the channel. The configuration is defined as a transmission pair of transmission branch and spreading code. The transmission branch may be the In-Phase (I) branch or the Quadrature (Q) branch. PAR analysis may be performed off-line to determine the optimum configuration. In operation, if the spreading code of the optimum configuration is used by another channel, the next best optimum code is used.

Abstract: A technique and system is disclosed for controlling power in a spread spectrum system. A fast slot of a frame is received where the frame is divided into a number of fast slots. The received power is measured on the fast slot. A second fast slot is transmitted at a second time with a transmit power setting and a variable spreading factor. The transmit power setting and the variable spreading factor is adjusted based on the received power. The variable spreading factor affects the total number of fast slots that are transmitted.

Abstract: Systems and methods of combining OFDM and CDMA signals are provided. An OFDM packet data channel is overlaid over CDMA transmissions. The channel is scheduled slotwise between multiple users. In some embodiments, there is a CDMA packet data channel which is scheduled together with the OFDM packet data channel.

Abstract: A radio communication system that uses multiple antennas to transmit signals to a plurality of mobile terminals, and that measures the reception quality of each signal that is transmitted from each antenna on a transmitting side and received by the mobile terminal, determines a main antenna based on that reception quality for real-time communication, calculates multi-dimension correlation between the main antenna and other antennas, selects resources where the multi-dimension correlation is lower than a set value, feeds back data to the transmitting side indicating the main antenna, low correlation resources and reception qualities, designates antennas having resources of low correlation as diversity antennas, and performs diversity transmission from the transmitting side of signals to the mobile station using those diversity antennas and the main antenna.

Abstract: Techniques are described for carrier frequency offset (CFO) and channel estimation of orthogonal frequency division multiplexing (OFDM) transmissions over multiple-input multiple-output (MIMO) frequency-selective fading channels. A wireless transmitter forms blocks of symbols by inserting training symbols within two or more blocks of information-bearing symbols. The transmitter applies a hopping code to each of the blocks of symbols to insert a null subcarrier at a different position within each of the blocks of symbols, and a modulator outputs a wireless signal in accordance with the blocks of symbols. A receiver receives the wireless signal and estimates the CFO, and outputs a stream of estimated symbols based on the estimated CFO.

Abstract: The present invention relates to a method and an apparatus for spread spectrum modulation and demodulation using a special spread spectrum sequence, characterized in that Golay complementary codes are modulated onto orthogonal channels such that a corresponding complex complementary code is obtained. The signal spread by such complex complementary code has a low peak-to-average power ratio, a sound self-correlation property and cross-correlation property, which can well solve the problem of multi-access interference such that the communication performance of the entire system is improved.

Abstract: The present invention describes a spread spectrum communication system wherein the frequency of carriers and the code channels of the carriers or both for transmission to a given remote station user vary in time. This provides for a direct sequence spectrum communications system which changes frequency or code channel according to a predetermined pattern. The code channels and frequencies can be determined in accordance with a deterministic function or based upon a subset of the data to be transmitted. A receiver structure is also described for receiving the same.

Abstract: A communication method for embedding a meta-carrier under an original carrier signal with reduced or minimal original carrier signal degradation, the method comprising transmitting an original carrier signal and transmitting a meta-carrier signal separate from the original carrier signal, wherein the meta-carrier signal contains information about an original carrier signal, is extractable under an interfered condition, and is transmitted such that the meta-carrier signal occupies at least a portion of a bandwidth of the original carrier signal.

Abstract: A wireless communication apparatus capable of minimizing the degradation in separation characteristic of a code multiplexed response signal. In this apparatus, a control part (209) controls both a AC sequence to be used in a primary spreading in a spreading part (214) and a Walsh sequence to be used in a secondary spreading in a spreading part (217) so as to allow a very small circular shift interval of the ZC sequence to absorb the interference components remaining in the response signal; the spreading part (214) uses the ZC sequence set by the control part (209) to primary spread the response signal; and the spreading part (217) uses the Walsh sequence set by the control part (209) to secondary spread the response signal to which PC has been added.

Abstract: The present invention provides for spreading a first signal using a plurality of spreading codes, multiplexing the first spread signal by code division multiplexing, transmitting the first multiplexed signal via a plurality of neighboring frequency resources of an OFDM symbol of a first antenna set, spreading a second signal using a plurality of spreading codes, multiplexing the second spread signal by code division multiplexing, transmitting the second multiplexed signal via a plurality of neighboring frequency resources of the OFDM symbol of the first antenna set, transmitting the first multiplexed signal via a plurality of neighboring frequency resources of an OFDM symbol of a second antenna set, and transmitting the second multiplexed signal via a plurality of neighboring frequency resources of the OFDM symbol of the second antenna set, wherein the first multiplexed signal is transmitted on frequency resources that neighbor frequency resources that the second multiplexed signal is transmitted on.

Abstract: A multi-carrier spread spectrum device using cyclic shift orthogonal keying includes: a modulation unit for receiving a first part of data bits and transforming the first part of data bits to a modulation symbol di by modulation; a cyclic-shift unit for receiving a base code c(0) and a second part of data bits, and performing a cyclic-shift to the base code c(0) in accordance with the second part of data bits to generate a CSOK symbol c(mi); and a multiplier for multiplying the modulation symbol di by the CSOK symbol c(mi) to generate a spread spectrum signal ci.

Abstract: A transmitter comprises a first spreading unit configured to multiply each of multiple data symbols with a first spreading code sequence of a first spreading factor; a compression and repetition unit configured to compress output signals of the first spreading unit in time domain and repeat the compressed signal L times (where L is a natural number greater than or equal to 2); a phase modulation unit configured to multiply the compressed and repeated signal with a user dependent phase and output a data block consisting of L sub-blocks; a second spreading unit configured to replicate the data block according to a second spreading factor and multiply each set of the replicated sub-blocks with a second spreading code sequence of the second spreading factor to produce a two-dimensionally spread signal; and a wireless transmission unit configured to transmit the two-dimensionally spread signal using a single-carrier transmission scheme.

Abstract: The present invention provides for transmitting a spread signal in a mobile communication system. The present invention includes spreading a signal using a plurality of spreading codes, wherein the plurality of spreading codes have a spreading factor, multiplexing the spread signal by code division multiplexing, transmitting the multiplexed signal via a plurality of neighboring frequency resources of one OFDM symbol of a first antenna set, and transmitting the same multiplexed signal via a plurality of neighboring frequency resources of one OFDM symbol of a second antenna set.

Abstract: Methods and apparatus for use in a multi-band OFDM wideband transmission systems are disclosed. A frame of source data is mapped by a transmitter for transmission using a first mapping. The frame of source data is then mapped by the transmitter for retransmission using a second mapping to increase frequency diversity. A receiver may identify source data that experiences fading and communicate the tone/frequency on which the fading occurred to the transmitter so that the transmitter may map the source data that experienced fading during transmission to another tone/frequency for retransmission.

Abstract: A template pulse generating circuit that generates a template pulse used for detection of a received pulse in pulse communication includes an output mode switching circuit for switching an output mode in accordance with a supplied control signal between a continuous output mode that continuously outputs the template pulses and an intermittent output mode that intermittently outputs the template pulses so that the template pulse is generated in either one of the continuous output mode and the intermittent output mode.