Abstract: A transmitter according to the present invention includes a mapping unit configured to convert transmitted data into data pieces associated with individual subcarriers, an inverse Fourier transform unit configured to convert the data pieces into a time-series signal, and a symbol generation unit configured to generate symbols for radio transmission from the time-series signal. The mapping unit associates the transmitted data with subcarriers different from predefined multiple subcarriers arranged at even intervals on a frequency axis. A demapping unit of a receiver according to the present invention supplies data comprising the data pieces associated with the subcarriers different from the predefined multiple subcarriers arranged at even intervals on a frequency axis as the data for restoration.

Abstract: To generate a pulse for ranging, a kernel is convolved with a spreading sequence. The spreading sequence is parametrized by one or more ordered (length, sparsity) pairs, such that the first sparsity differs from the bit length of the kernel and/or a subsequent sparsity differs from the product of the immediately preceding length and the immediately preceding sparsity. Alternatively, a kernel is convolved with an ordered plurality of spreading sequences, all but the first of which may be non-binary. The pulse is launched towards a target. The reflection from the target is transformed to a received reflection, compressed by deconvolution of the spreading sequence, and post-processed to provide a range to the target and/or a direction of arrival from the target.

Abstract: Described herein are code-modulated multi-signal systems. In one embodiment, a multi-signal system receives multiple input signals and code-modulates each input signal with a unique code to distinguish the input signal from the other input signals. The input signals may come from multiple antennas, multiple sensors, multiple channels, etc. The code-modulated signals are then combined into a combined signal that is sent through shared blocks and/or transmitted across a shared medium in a shared path. After shared processing and/or shared transmission, the individual signals are recovered using matched filters. Each matched filter contains a code corresponding to one of the unique codes for recovering the corresponding signal from the combined signal. The recovered signals may then be inputted to additional processors for further processing.

Abstract: The present invention includes a method of determining a phase estimate for an input signal having pilot symbols. The method includes receiving a plurality of pilot symbols, and then multiplying two or more pilot symbol slots by corresponding correlator coefficients to correct a phase estimate of the input signal.

Abstract: A high-frequency switch module includes a first switching element and a second switching element. A common terminal of the first switching element is connected to an antenna. A common input terminal of the second switching element is connected to a multi-band power amplifier. A second individual output terminal of the second switching element is connected to a fourth individual terminal of the first switching element via a first low-pass filter, and is connected to a third individual terminal of the first switching element via a series circuit including a second low-pass filter and a high-pass filter. A first individual output terminal of the second switching element is connected to a first individual terminal of the first switching element via a phase-shift circuit and a first SAW duplexer, and is connected to a second individual terminal of the first switching element via the phase-shift circuit and a second SAW duplexer.

Abstract: A wireless network (20) with at least a first radio communication unit (24) and a second radio communication unit (26) transmits and receives signals with minimal interference from the surrounding environment of the first unit (24) and second unit (26). The first radio communication unit (24) determines frequencies (54) having power level above a threshold (52), and creates a list of these frequencies (50) to be transmitted to the second radio communication unit (26). The second radio communication unit (26) places notches (140) in its transmission band (88) based on frequencies (54) in the list (50), reserved frequencies (132), and local frequencies (92) having signal energy above a threshold (90). When transmitting a signal (42), the second radio communication unit (26) avoids transmitting in frequencies that have notches (140).

Abstract: Provided is a radio communication device which can improve the negative acknowledgement (NACK) error rate characteristic. The device includes: a scrambling unit (214) which multiplies a response signal after modulated, by a scrambling code “1” or “?1” so as to inverse a constellation for each of response signals on a cyclic shift axis; a spread unit (215) which performs a primary spread of the response signal by using a zero auto correlation (ZAC) sequence set by a control unit (209); and a spread unit (218) which performs a secondary spread of the response signal after subjected to the primary spread, by using a block-wise spread code sequence set by the control unit (209).

Abstract: A method for conserving bandwidth in a communication system includes spreading a data frame and a broadcast frame. A complex data stream having a first component and a second component is generated. The data frame is assigned to the first component and the broadcast frame is assigned to the second component. The complex data stream is transmitted to a tag.

Abstract: The present invention provides a method for transmitting paging information in orthogonal frequency-division multiplexing (OFDM) systems as well as the transmitter and receiver apparatus for its application. The method features itself in the following aspects: An auxiliary paging channel is employed dedicatedly for spread-spectrum modulation or digital modulation of the paging information. When the receiver is in a standby state, paging information can be obtained by means of spread spectrum demodulation or digital demodulation with no need to conduct FFT. This leads to a great reduction in power consumption and less power is consumed when the receive devices are in standby state, hence achieving aim to lengthen the usable time of a battery in a mobile phone.

Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying data that is designated for wireless transmission to a remote computing device. A digital signal that encodes the data for transmission across a band of radio frequency channels is generated. Multiple radio frequency channels in the band that are available are determined. The digital signal is filtered to substantially reduce a power level of the digital signal at frequencies that correspond to channels in the band that have not been determined to be available. The filtered digital signal is converted to an analog signal. The analog signal is provided to an analog transmitter that isolates the band of channels to generate an isolated analog signal and that wirelessly transmits the isolated analog signal over the multiple available channels using one or more antennas.

Abstract: Methods, systems, and apparatuses, including computer programs encoded on computer-readable media, for receiving monitor data from a lighting equipment monitor. A data stream is created based upon the monitor data. The data stream is spread with a common pseudo-noise (PN) code that is used by a plurality of nodes in communication with an access point. A frequency offset to the spread data stream based at least in part on a timing of the access point is applied. The spread data stream is transmitted with a randomly selected timing offset.

Abstract: A method of embedding and transmitting a meta-data message in an original burst carrier signal for message reassembly comprising spreading a meta-carrier signal using a Direct Sequence Spread Spectrum (DSSS) spreading code having a Pseudo-Random Noise (PRN) spreading code sequence, the meta-carrier signal comprising one or more bits of meta-data information about the original burst carrier signal, lowering a power spectral density of the meta-carrier signal using the PRN spreading code such that interference with the original signal is reduced, combining the original burst carrier and the meta-carrier signals using a modulator such that a composite burst carrier signal results wherein the meta-carrier signal occupies at least a portion of a bandwidth of the original carrier, and transmitting the composite burst carrier using a transmitter over a telecommunications channel in which only one burst carrier signal is expected to be present within a predetermined frequency bandwidth at a point in time.

Abstract: A method and apparatus for enabling the operative association of electronic devices that each employ spread spectrum EMI noise reduction. The method includes the detection of frequency modulation and the generation of a modulation detection signal that conveys the modulation extent and type. The modulation detection signal is then used to accommodate the modulation technique and make it compatible with the receiving electronic device. The apparatus of the invention includes an FM modulator that creates an FM signal from an input signal, an FM detector that detects the FM content of the incoming signal and represent this information by means of either voltage or current signals, and a circuit to process this FM information and perform functions such as modification of the FM content and generating a new signal with this new content, complete removal of the content, and “no-action,” whereby the signal is passed on with no alteration to the content.

Abstract: A method for facilitating transmission of data in a communication system is provided herein. In operation, a base radio of a plurality of base radios combines status information corresponding to a plurality of inbound frequencies and transmits the combined status information on a single outbound radio frequency. Further, each of the plurality of inbound radio frequencies corresponds to one of the plurality of base radios. Then, one or more radio terminals monitor the single outbound radio frequency to receive the combined status information, determine at least one available inbound radio frequency from the plurality of inbound radio frequencies based on the received combined status information, selects an inbound radio frequency of the at least one available inbound frequency, and transmitting the data using the selected inbound radio frequency to the corresponding base radio.

Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying data that is designated for wireless transmission to a remote computing device. A digital signal that encodes the data for transmission across a band of radio frequency channels is generated. Multiple radio frequency channels in the band that are available are determined. The digital signal is filtered to substantially reduce a power level of the digital signal at frequencies that correspond to channels in the band that have not been determined to be available. The filtered digital signal is converted to an analog signal. The analog signal is provided to an analog transmitter that isolates the band of channels to generate an isolated analog signal and that wirelessly transmits the isolated analog signal over the multiple available channels using one or more antennas.

Abstract: A method for transmitting signals for interference randomization is disclosed. The method for transmitting signals includes spreading the transmission signals using a plurality of orthogonal codes and transmitting the transmission signals spread by the plurality of orthogonal codes by a spatial frequency block coding (SFBC) or spatial time block coding (STBC) scheme. Among the plurality of orthogonal codes, codes of which mutual interferences are equal to or greater than a predetermined threshold are grouped to the same group, and orthogonal codes belonging to different groups are used for the spreading of the signals which are transmitted at the same timing. Accordingly, it is possible to realize interference randomization.

Abstract: A wireless device comprising a plurality of chips may be operable to communicate wireless signals via a mesh network comprising a plurality of integrated directional antennas on the plurality of chips. Wireless signals may be communicated between the plurality of the chips and/or with devices external to the wireless device via the mesh network. Beam-formed wireless signals may be communicated via the plurality of integrated directional antennas. The plurality of chips may be integrated on a single package or on a plurality of packages, which may comprise one or more circuit boards. Wireless signals may be communicated with devices external to the single package via the mesh network. The directional antennas may comprise patch antennas and/or dipole antennas.

Abstract: The present disclosure relates generally to a system and method for scrambling in a wireless communication system. In one example, the method includes receiving a bit group representing at least a portion of a signal, where a total number of bits in the bit group is defined by a modulation scheme applied to the signal. A bit of the bit group is identified that indicates a sign of an imaginary part of the signal and another bit of the bit group is identified that indicates a sign of a real part of the signal. Only the two bits indicating the signs of the imaginary and real parts of the signal are scrambled using a random sequence prior to wirelessly transmitting the bit group.

Abstract: An adjustable code generator is configurable to generate any of a plurality of spread-spectrum code signals. The adjustable code generator includes a feedback polynomial mask table to contain a set of feedback polynomial masks. Respective feedback polynomial masks of the set correspond to respective spread-spectrum code signals of the plurality of spread-spectrum code signals. The adjustable code generator also includes control logic to select any of the feedback polynomial masks of the set contained in the feedback polynomial mask table, and further includes a shift register to provide, at an output, a respective spread-spectrum code signal that corresponds to a feedback polynomial mask selected by the control logic and to receive feedback generated using the feedback polynomial mask selected by the control logic.

Abstract: A radio frequency transmission module is adapted to generate a first signal to be transmitted and to convert the signal to a radio frequency carrier for its radio transmission, in an operational phase, and is adapted to generate a second signal and to convert the second signal to the radio frequency carrier, in a calibration phase. The module includes a calibration unit having a subsampler adapted to subsample the second converted signal and a calculation unit adapted to calculate Fourier Transform coefficients representative of the signal delivered by the subsampler, for the purposes of processing the first signal to be transmitted, in the operational phase, as a function of at least some of the Fourier coefficients calculated in the calibration phase.

Abstract: A positioning system receiver that mitigates narrowband interference by dynamically choosing the mitigation technique that yields the best interference mitigation capability with the least signal degradation to maximize receiver performance parameters such as receiver sensitivity, multipath resolution, and low power.

Abstract: A signal transmission apparatus includes: a reference signal outputting section adapted to output a reference signal; a first clock production section adapted to produce, based on the reference signal, a first clock signal for a first signal process regarding a radio communication process of a spectrum spreading method in synchronism with the reference signal; a first signal processing section adapted to carry out the first signal process based on the first clock signal; a second clock production section adapted to produce, based on the reference signal, a second clock signal for a second signal process corresponding to the first signal process in synchronism with the reference signal; and a second signal processing section adapted to carry out the second signal process based on the second clock signal.

Abstract: Certain aspects of the present disclosure relate to a method for generating spread-spectrum coded signals for transmission in a wireless communication system, and particularly for generating spread sequences of data with spreading codes that facilitate computationally efficient frequency-domain processing at a receiver.

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 by a transmitter, forming a meta-carrier signal separate from the original carrier signal that contains meta-data about the original carrier signal including one or more characteristics of the original carrier signal configured for use by a receiving device to establish one or more parameters of a receiving device to receive the original carrier signal at the receiving device, and transmitting the meta-carrier signal by the transmitter separate from the original carrier signal such that the meta-carrier signal occupies at least a portion of a bandwidth of the original carrier signal.

Abstract: Data comprising a pulse signal is divided into predetermined data segments. The number of pulse-signal fluctuations in the data segment is counted. A transmitter transmits the unchanged data to a receiving portion in a case where the number of pulse-signal fluctuations does not exceed a predetermined number. On the other hand, in a case where the number of pulse-signal fluctuations exceeds the predetermined number, the pulse signal is converted so as to be unchanged at the fluctuation of the pulse signal but to be fluctuated when the pulse signal does not fluctuate. Then, the transmitter transmits the converted pulse signal to the receiving portion wherein only the converted pulse signal is converted to the original pulse signal.

Abstract: Embodiments of the present invention provide a method to produce a modulation signal comprising combining at least two modulation signals, for example, BOCs or derivatives thereof, having portions (chip or a number of chips) thereof with respective relative phases or states ({++, ??} and {+?, ?+}) selected such that the average of a plurality of said portions at least reduces cross spectral terms of the composite complex spectrum of said at least two modulation signals.

Abstract: A system includes at least a transmitter having a serial-to-parallel converter, an iFFT block and a frequency de-spreader device that applies each signal that results from multiplying a data sample by one of the predetermined frequency coefficients of the prototype filter of a synthesis filter bank to one of the inputs of the iFFT block presenting a size that is strictly greater than the number of subchannels. Also described is a system including at least one receiver including a serial-to-parallel converter, a FFT block presenting a size that is strictly greater than the number of subchannels of the system, and a frequency de-spreader device that multiplies the signal from each output of the FFT block by one of predetermined frequency coefficients of the prototype filter of an analysis filter bank and sums the results of these multiplications to deliver at least a portion of the output signal from the receiver.

Abstract: A transmission signal processing method is provided, for generating a first OFDM modulation signal and a second OFDM modulation signal which are transmitted in an identical frequency band, by utilizing a first antenna for transmitting the first OFDM modulation signal and by utilizing a second antenna for transmitting the second OFDM modulation signal. The method includes a step of generating the first OFDM modulation signal and the second OFDM modulation signal utilizing a plurality of OFDM modulation signal generators, and a step of outputting the first OFDM modulation signal to the first antenna and the second OFDM modulation signal to the second antenna.

Abstract: There is provided a signal processing device and a wireless apparatus capable of not erroneously determining polarity, appropriately performing a spread modulation process, a carrier modulation process, and reception data demodulation process, improving reception accuracy, and miniaturizing a circuit, even when IF carrier frequency shift occurs.

Abstract: An apparatus and method for assigning subchannels of a transmitter in a communication system. The method includes dividing an entire frequency band into m subcarrier groups; mapping each of the m subcarrier groups to a subcarrier group index, wherein a subchannel includes n subcarriers selected from each of the m subcarrier groups corresponding to a subcarrier group index sequence; determining that a first data is needed to transmit in a first timing point; and assigning a first subchannel in the first timing point using a first subcarrier group index sequence. The first subcarrier group index sequence is different from a second subcarrier group index sequence used for assigning a second subchannel in a second timing point.

Abstract: Systems and methods for generating spectrally shaped pseudo random noise sequences are described, which may include generating an L-level PN sequence, where L is an integer greater than 1; up-sampling the PN sequence by a factor of M, where M is an integer greater than 1; and filtering the up-sampled PN sequence using a finite impulse response (FIR) filter of length M, where the coefficients of the FIR filter are chosen from a set of pre-determined values.

Abstract: A communication system is provided that allows the use of low-cost, low-power remote terminal units that communicate substantially asynchronously and independently to a base station. To minimize cost and complexity, the remote terminal units are configured similarly, including the use of substantially identical transmission schemes, such as a common Direct Sequence Spread Spectrum (DSSS) code. To minimize collisions among transmissions, the communication system is designed to use a high-gain antenna with a limited field of view, to limit the number of cotemporaneous, or overlapping transmissions that are received at the base station. To cover a wide area, the limited field of view is swept across the area of coverage. To overcome potential losses caused by collisions, the remote terminal units are configured to repeat transmissions; to minimize repeated collisions, the repeat interval and/or duration is randomized.

Abstract: A pulse generator circuit is provided. The pulse generator circuit has an input adapted to receive an input electrical quantity and an output at which an output electrical quantity is made available. A transfer characteristic establishes a relationship between said input and said output electrical quantities. The pulse generator circuit is adapted to provide said output electrical quantity in the form of pulses having a predetermined shape, suitable to be used for UWB transmission. The transfer characteristic has substantially a same shape as that of said pulses. Moreover, a UWB modulating system exploiting the novel pulse generator is proposed.

Abstract: A communication technique based on direct sequence spread spectrum signaling employs, for all users sharing an access channel, a single spreading code that has a duration sufficiently longer than the symbol length that the likelihood of confusion between users is minimized if not eliminated. The length of the spreading code is sufficiently long that contention events can occur only when two bursts occur at the receiver within one chip time of one another.

Abstract: A method for providing a dual-channel beacon signal to protect a low-power device in a wireless network is provided. The method includes generating a beacon message in a first logical channel and generating a detection signal in a second logical channel. The first logical channel and the second logical channel are mapped into a first physical channel and a second physical channel. The second physical channel is orthogonal to the first physical channel. The dual-channel beacon signal is transmitted by simultaneously transmitting the beacon message and the detection signal in the first physical channel and the second physical channel.

Abstract: Method and apparatus for high rate code-division multiple access wireless communication is described. Each of a channel encoded data is modulated by an associated code having a small number of pseudo-noise spreading chips per orthogonal waveform period, thus producing a set of streams of modulated symbols. Each of the set of streams of modulated symbols is then gain adjusted, and combined to yield two streams of combined symbols. The combination is the set of streams is carried out to reduce a peak-to-average ratio of the transmission. The resulting two combined symbol streams are modulated by a complex multiplyer using a user long code and a pseudorandom spreading code (PN code) and upconverted for transmission.

Abstract: A wireless communication network supports 802.11b/g and a range extension mode, which supports at least one data rate lower than the lowest data rate in 802.11b/g. A transmitting station (which may be an access point or a user terminal) includes first and second processors. The first processor performs differential modulation and spectral spreading for a first set of at least one data rate (e.g., 1 and 2 Mbps) supported by 802.11b/g. The second processor performs forward error correction (FEC) encoding, symbol mapping, and spectral spreading for a second set of at least one data rate (e.g., 250, 500, and 1000 Kbps) supported by the range extension mode. The transmitting station can send a transmission at a data rate supported by either 802.11b/g or the range extension mode, e.g., depending on the desired coverage range for the transmission. A receiving station performs the complementary processing to recover the transmission.

Abstract: A wireless communication system and method uses a spatial spreading matrix to distribute the encoded spatial data streams to a number of transmit chains and further uses the spatial spreading matrix for antenna selection computation in a transmitter. The spatial spreading matrix is designed such that a receiver is able to know and utilize the spatial spreading matrix for computing transmission antenna selection, receiver antenna selection and joint transmission/receiving antenna selection. The use of this spatial spreading matrix for antenna selection computation provides increased accuracy in antenna selection for transmission of spatial data streams, where the number of spatial data streams is less than the number of transmit or receive chains between the transmitter and receiver, and the number of transmit or receive chains is less than the corresponding transmission or receiving antennas.

Abstract: A receiver for receiving a signal, the signal conforming to a protocol such that the signal comprises a synchronising portion and a data portion, each portion comprising pulses located in respective time slots, the time offsets between successive time slots being defined by the protocol, the receiver comprising: a detector configured to detect a first pulse and a second pulse of the synchronising portion; a comparison module configured to compare the time offset between the first and second pulses to a corresponding time offset defined by the protocol so as to determine the relationship between the detected time offset and the corresponding time offset; a determination module configured to determine expected times of arrival of the time slots of the data portion using the determined relationship and the time offsets defined by the protocol; and a data reader configured to read data conveyed in the data portion at the expected times of arrival.

Abstract: Adjusting parameters of a waveform includes facilitating wireless communication between a transmitting node and receiving nodes, where the transmitting node communicates with a receiving node over a channel. Spectrum conditions are estimated, where a spectrum condition describes spectrum utilization in the vicinity of surrounding nodes. Channel conditions are estimated, where a channel condition describes a channel of the plurality of channels. Waveform parameters are adjusted in response to the spectrum conditions and the channel conditions.

Abstract: To provide a mobile terminal apparatus, radio base station apparatus and radio communication method capable of supporting user multiplexing methods for enabling more users to be efficiently multiplexed on an uplink shared channel, the mobile terminal apparatus performs spreading processing for multiplying a data signal by a code varying for each user, and transmits the spreading-processed data signal to the radio base station apparatus on the uplink shared channel, and the radio base station apparatus receives the data signal, and user-separates a reception signal in which is mixed a plurality of users multiplied by spreading codes varying for each user into desired user signals to be data signals for each user.

Abstract: Systems and methods for providing an efficient mechanism for transmitting information needed to receive a secondary carrier over an existing message protocol on a primary carrier for a multiple carrier capable communications terminal. The receiver terminal may receive, on a primary carrier, a message containing information including a timing offset and a cell identification for a secondary carrier, for example. The communications terminal may then correlate a receiver to receive the secondary carrier without the need for a separate synchronization signal on the secondary carrier. These embodiments result in additional efficiency in a communications system.

Abstract: An apparatus and method for combining transponder bandwidths comprises a wide-band virtual transponder for transmitting a single data stream. The wide-band virtual transponder is comprised of a plurality of narrow-band physical transponders. A plurality of elementary streams are statistically multiplexed to create the single data stream, wherein the single data stream is forward error correction encoded and demultiplexed into a plurality of transponder streams for transmission by the plurality of physical transponders. The physical transponders each use a different portion of a signal spectrum, wherein the different portion may be guard bands or a combination of legacy bands and guard bands. Upon receipt, the transponder streams are multiplexed to recover the single data stream, wherein the recovered single data stream is forward error correction decoded and statistically demultiplexed to recover the plurality of elementary streams.

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: An encoder encodes sound data and the like to generate a binary signal. A mapper converts the binary signal into a four-level symbol and outputs the four-level symbol. A base band filter includes a root raised cosine filter and a sinc filter. The base band filter blocks a predetermined frequency component of a symbol to shape the symbol into a waveform signal and outputs the waveform signal shaped. An FM modulator transmits a signal subjected to FM modulation according to a magnitude of an amplitude of a waveform signal to a receiving unit. When a symbol of ±3 is outputted from the mapper, a frequency shift of a signal transmitted from the FM modulator has a predetermined value in a range of ±0.822[kHz] to ±0.952[kHz]. This makes it possible to provide a modulating apparatus, a mobile communication system, a modulating method, and a communication method that use a modulating method that can conform to the FCC rule to be enforced in 2005 without using a linear power amplifier.

Abstract: An arrangement of interleavers allocates bits from an input symbol across sub-symbols transmitted via sub-carriers of multiple orthogonal frequency division multiplex (OFDM) carriers. The input bits are allocated in a fashion to provide separation across subcarriers, and rotation of sub-symbols across the OFDM carriers provides additional robustness in the present of signal path impairments.

Abstract: A method for the wireless transmission of data between at least one communication unit (2) which is arranged in or on a rotatable part (1) and to which at least one sensor (S) and/or actuator is respectively connected, and at least one base communication unit (4) which is arranged in radio reception range outside of the rotatable part is described. Transmission of the data using the ultrawideband radio transmission method (UWB) on a frequency spectrum of more than 500 MHz or a frequency bandwidth of more than 0.2 times the average transmission frequency is proposed.

Abstract: A wireless telecommunications system includes a base station, a plurality of remote stations, a first channel for general page messages containing paging information and broadcast databurst message references, and an auxiliary channel for broadcast databurst notification indicators for the purpose of increasing standby time in remote stations configured to receive broadcast databurst messages.

Abstract: An apparatus for generating a monocycle comprises an input signal source (76) for providing an input signal, and a step recovery diode (SRD) (80) for receiving the input signal and producing an impulse. A shunt inductor (102) is provided to act as a first differentiator and a capacitor (92) connected in series to the output of the step recovery diode acts as a second differentiator. The first and second differentiators are arranged to double differentiate the impulse to produce a monocycle.

Abstract: A spread-spectrum signal comprises a spreading waveform modulating a carrier wave and containing a real linear combination of a first waveform at a first waveform rate and a second waveform at a second waveform rate, the first waveform rate being distinct from the second waveform rate and both waveform rates being distinct and non-zero. The linear combination of the first and the second waveform is modulated with at least one binary sequence comprising a signal identification code.