Abstract: This inventive wireless communication system comprises a plurality of wireless communication devices (101) each including a radiating oscillator (1), a baseband signal generating unit (4) and a reception signal detecting unit (7).

Abstract: A clock signal generating arrangement for a communication device generates a system clock signal at an output for use as a timing reference. The clock signal generating arrangement comprises a reference clock generator for generating a reference clock signal, a main clock generator for generating a main clock signal having a greater accuracy than the reference clock signal, a clock adjust circuit coupled to the reference clock generator for generating a compensated reference clock signal to compensate for error in the reference clock signal and a clock signal selector coupled to the reference clock generator the main clock generator and the clock adjust circuit.

Abstract: An embodiment of the present invention discloses a microwave relay receiving method and apparatus, a microwave relay transmitting method and apparatus, and a microwave relay node. The embodiment of the present invention relates to the field of communications technologies and is invented to enable free scheduling of microwave signals at low costs. The microwave relay receiving method includes: receiving a microwave signal; separating the microwave signal to obtain service information at an intermediate frequency band and control information at a low frequency band and sending the separated service information to a switch matrix; and sending the control information to the switch matrix so that a corresponding switch in the switch matrix is turned on and the service information is transmitted by the turned on switch.

Abstract: A method for communication includes transmitting data from a transmitter to a receiver using Adaptive Coding and Modulation (ACM). The data rate is set by selecting, based on feedback, an ACM profile defining a Forward Error Correction code and a modulation scheme. Upon detecting that the feedback is unusable, an operation of the transmitter is changed independently of the feedback. In another method, data is exchanged over two opposite directions of a bidirectional link that uses ACM by communicating using two ACM profiles. A joint constraint is defined on the two directions. The two ACM profiles are set based on first and second measured reception quality metrics of the two link directions, to meet the joint constraint. In yet another method, a subset of the ACM profiles is temporarily disabled, and the data is transmitted using only the ACM profiles that are not disabled.

Abstract: A method for communication includes transmitting data from a transmitter to a receiver using Adaptive Coding and Modulation (ACM). The data rate is set by selecting, based on feedback, an ACM profile defining a Forward Error Correction code and a modulation scheme. Upon detecting that the feedback is unusable, an operation of the transmitter is changed independently of the feedback. In another method, data is exchanged over two opposite directions of a bidirectional link that uses ACM by communicating using two ACM profiles. A joint constraint is defined on the two directions. The two ACM profiles are set based on first and second measured reception quality metrics of the two link directions, to meet the joint constraint. In yet another method, a subset of the ACM profiles is temporarily disabled, and the data is transmitted using only the ACM profiles that are not disabled.

Abstract: A device and method to compensate for distortions of amplitude that afflict systems for communicating through capacitive coupling. A circuit includes a first transmitter stage, a first receiver stage, and a first coupling capacitor, coupled between the first transmitter stage and the first receiver stage. The first receiver stage includes a calibration amplifier of a variable-gain type coupled between the first coupling capacitor and an output of the electronic circuit. The electronic circuit includes a reference channel formed by: a transmission calibration stage; a reception calibration stage; and a reference capacitor coupled between the transmission calibration stage and the reception calibration stage.

Abstract: A system and method of applying a known modification to a signal to enable a determination of a signal received by a first node is received directly from a second node or indirectly through a repeater. The repeater receives a primary signal and creates a secondary signal as a function of the primary signal and a known modification, wherein the known modification identifies the repeater. The primary signal is transmitted and injected with the secondary signal as the first signal to the primary receiver.

Abstract: A communication control method, for a radio communication system including a radio base station, a radio terminal, and a relay station that receives a radio signal transmitted from the radio base station and relays the radio signal to the radio terminal at a transmission frequency different from a reception frequency, includes broadcasting information on one or more transmission frequencies of radio base stations or relay stations from the radio base station; and determining, by the radio terminal, whether transmission-source identification information included in the radio signals that are received before and after switching the reception frequency match, the switching being conducted based on the information broadcasted from one of the radio base station directly and via the relay station, wherein if the radio terminal determines that the transmission-source identification information matches, the radio terminal omits a terminal registering procedure after frame-synchronization with the radio communication

Abstract: Provided is a mobile communication system which includes a plurality of RAT (Radio Access Technology) and can eliminate the need of a control channel for reporting RAT information so as to prevent congestion or shortage of the control channel capacity. In the mobile communication system, an LTE relay station (30) has a cover area (31) identical to a cover area (21) owned by a WLAN host station (20) and relays/transmits the signal received from an LTE base station (10) to a mobile station (40) in the cover area (31). The LTE relay station (30) adds to the signal received from the LTE base station (10), one of the offsets: a frequency offset, a time offset, and a power offset as information indicating that the mobile station (40) which receives a relay signal from the local station is located in the cover area (21) of WLAN and transmits the signal after offset addition to the mobile station (40) located in the cover area (31) (i.e., the cover area (21)).

Abstract: An FM radio with a wide frequency range operates in a cell phone without interfering with the VCO of the RF transceiver. The FM transceiver generates a VCO signal whose frequency varies by less than ±7% from the midpoint of a narrow first range. A synthesizer signal is generated by dividing the VCO frequency by a first divisor such that the synthesizer frequency varies over a lower frequency second range. The VCO frequency is also divided by a second divisor such that the synthesizer frequency varies over a third range. The upper limit of the second range falls at the lower limit of the third range. The lower limit of the second range is 85.5 MHz and the upper limit of the third range is 108.0 MHz. By also using a third divisor, a synthesizer signal with a range of 76-108 MHz is generated from the narrow first frequency range.

Abstract: A radio frequency repeater is provided. A donor antenna transmits a signal to and receives a signal from a base station. A service antenna transmits a signal to and receives a signal from a mobile station. A repeater filters and amplifies a signal between the two antennas. A polarization variation unit variably selects a polarization direction of at least one of the donor antenna and the service antenna in response to a detection signal of an isolation detector for detecting isolation between the two antennas. The isolation between the donor antenna and the service antenna can be sufficiently ensured.

Abstract: A method and apparatus for reconfiguring a wireless transmit/receive unit (WTRU) are directed to receiving an active set update message indicating that a mode of operation allowing a certain modulation scheme is enabled or disabled and performing at least one of: performing a MAC reset procedure, updating a set of reference enhanced transport format combination indicators (E-TFCIs) and associated power offsets, determining actions related to E-DPCCH boosting, modifying information related to an enhanced dedicated channel (E-DCH), and modifying an index that indicates an E-DCH transport block size table. The update message includes at least one modified information element (IE).

Abstract: A radio-frequency circuit for a wireless signal transceiver is disclosed. The wireless signal transceiver is utilized for receiving a first wireless signal and transforming the first wireless signal into a second wireless signal. The radio-frequency circuit includes a transmission line including a first end and a second end, a reception antenna coupled to the first end of the transmission line for receiving the first wireless signal, a transmission antenna coupled to the first end of the transmission line for emitting the second wireless signal, a first filtering circuit coupled between the second end of the transmission line and the wireless signal transceiver for filtering out the first wireless signal, and a second filtering circuit coupled between the second end of the transmission line and the wireless signal transceiver for filtering out the second wireless signal.

Abstract: Object To reduce deterioration of transmission quality under circumstances where the moving speed is high. Overcoming Means An adaptive modulation control apparatus for adaptively selecting a modulation parameter from among a plurality of modulation parameters determined based on a plurality of modulation schemes, coding rates of error correction or a combination thereof corresponding to a propagation path state is provided with a reception state measuring section (2) that measures a reception state of a signal received from a communicating apparatus, a correcting section (3) that makes a correction to change propagation path information indicative of a measurement result of the propagation path state based on the measured reception state, and a modulation parameter selecting section (4) that selects a modulation parameter corresponding to the corrected propagation path information.

Abstract: A system and method for converting a note-based audio object to a Pulse Code Modulated (PCM) audio format is disclosed. An electronic computer device includes a memory containing a note-based audio object and a lookup table, the note-based audio object containing note frequency information. A processor is configured for converting the note-based audio object to a Pulse Code Modulated (PCM) stream having a plurality of sample points, the converting including: generating a PCM value for each sample point based upon the note frequency and the trigonometric function evaluations, selecting an entry from the look-up table based upon the note frequency information, a sampling frequency, and a sample point number, and determining a step size within the look-up table based upon a ratio between the note frequency information and the sampling frequency.

Abstract: A wireless communication device having extremely simple constitution is used, and a low-cost and low power consumption wireless network system with high-quality signals is provided. The wireless network system comprises a plurality of wireless communication devices (101) each comprising a radiating oscillator (1) configured to integrate a transistor into a microwave oscillating resonator to generate a negative resistance and to commonly use a function of an antenna (11), an intermediate frequency signal generating section (4) and a receiving signal detecting section (7).

Abstract: A method for verifying alignment between first and second integrated devices coupled together using a reference and a coupling capacitor, including: transmitting a reference signal on a transmission electrode of the reference capacitor; receiving a coupling signal on a reception electrode of the reference capacitor; amplifying the coupling signal, generating a reception reference signal; generating a reception control signal as a function of the reception reference signal; transmitting a communication signal on an electrode of the coupling capacitor; receiving a reception signal on an electrode of the coupling capacitor; amplifying the reception signal, generating a first compensated signal; controlling a level of amplification of amplifying the coupling signal and the reception signal as a function of the reception control signal; and detecting a possible misalignment between the first and second devices based on an amplitude of the communication signal and an amplitude of the compensated signal.

Abstract: A modular satellite transceiver is provided according to some embodiments of the disclosure. The modular transceiver may include an RF module and a back end module. The RF module may operate in a first band, and may include, for example, one or more antennas, an RF front end module, an up converter, a down converter, an analog-to-digital converter, and a digital-to-analog converter. The back end module may include various digital processing components and/or modules. The RF module may be removably coupled with the back end module such that the RF module may be replaced with another RF module operating in a second band. During transmission the back end module may provide at least one digital signal to the RF module; and during reception the RF module provides at least one digital signal to the back end module.

Abstract: A wireless communication device includes a speaker grille, a built-in speaker provided behind the speaker grille, and an output amplifier connected to the built-in speaker. A voltage applied to the output amplifier is increased to a level higher than the level of voltage applied to the output amplifier while audio signals are being produced, and instead of the audio signals, low-frequency continuous signals are applied to the output amplifier. By increasing the voltage applied to the output amplifier to a level higher than the level of voltage applied to the output amplifier while audio signals are being produced, the amplitude of the voltage applied to the speaker is increased. Also, instead of the audio signals, low-frequency continuous signals are applied to the output amplifier so that the speaker produces a higher sound pressure than while audio signals are being produced to discharge water in the speaker grille under the sound pressure.

Abstract: A method and system are presented for operating a multibeam satellite system involving positioning a plurality of service beams associated with a plurality of service beam coverage areas and positioning a feeder beam associated with a feeder beam coverage area. The feeder beam coverage area is at a proximity to at least one service beam coverage area. The feeder beam coverage area includes at least one gateway. Each of the plurality of service beam coverage areas uses a color. The at least near service beam coverage area uses at least one color from the plurality of colors. The feeder beam uses at least one color, excluding the at least one color used by the at least one near service beam coverage area.

Abstract: The present invention provides a Wireless Local Area Network (WLAN) terminal, having a wireless interface that exchanges packetized communications with servicing Access Points (APs). A processing unit communicatively coupled to the wireless interface selects an appropriate programmable COder/DECoder (CODEC) with which to convert incoming packetized communications to incoming user communications, and outgoing user communications to outgoing packetized communications. A user interface coupled to the programmable CODEC receives the incoming user communications and produces the outgoing user communications. The processing unit monitors the serviced packetized communications to determine a communication quality level delivered by the wireless interface. Then the processing unit chooses the selected coding scheme based upon the communication quality level.

Abstract: A split delay-line oscillator for secure data transmission is disclosed. In one embodiment, an apparatus for a split delay-line oscillator for secure data transmission includes a first modulator/demodulator block in a first device, the first modulator/demodulator block operable to insert a first variable delay to modulate a frequency of a shared carrier signal passing through the first modulator/demodulator block, and a second modulator/demodulator block in a second device, the second modulator/demodulator block operable to insert a second variable delay to modulate the frequency of the shared carrier signal passing through the second modulator/demodulator block, wherein the first and second devices create a shared secret by contributing data on the frequency-modulated shared carrier signal.

Abstract: A feedback loop is used to determine phase distortion created in a signal by directly extracting the phase distortion information from a feedback signal using original frequency modulation information.

Abstract: A wireless receiver having improved receiving characteristics is provided.

Abstract: A demodulation section 13 receives a TDMA-TDD based phase-modulated burst signal of mobile communications and demodulates the burst signal by a synchronous detection system (or a quasi-synchronous detection system). The demodulation section 13 includes a frequency deviation compensation section and a carrier recovery section each having a loop filter 14 with three or more stages of time constants. The time constants are switched by a selector switch 15 based on a control signal from a demodulation control section 16. This achieves quick pull-in and jitter after convergence is minimized, thereby allowing highly efficient performance of frequency deviation compensation, etc. that is required for synchronous detection (or quasi-synchronous detection) without increasing the size of circuit.

Abstract: An electroluminescent light source includes a substrate and a layer structure applied to the substrate for emitting light at least on the side facing away from the substrate. The layer structure includes an electroluminescent layer between two electrodes. A partially transparent encapsulation device forms a closed volume around the layer structure, and is filled with a dielectric fluid which is substantially chemically inert with respect to the layer structure. The fluid contains particles for absorbing parts of the light emitted by the layer structure and for re-emitting light of a different wavelength. The density of the particles is selected such that the particles in the dielectric fluid are in the suspended state in the operational state of the light source.

Abstract: Systems and methods are disclosed for an electronically adjustable signal filter system, which comprises, in some embodiments, a first filter coupled to an antenna coupling network and a second filter, a power amplifier coupled to the first filter, an antenna connected to an antenna coupling network, a pilot tone generator coupled to the first filter, and a first signal source connected to the power amplifier and first filter. In some embodiments, the power amplifier amplifies the first signal, the first filter places a notch into the first signal transmitted to the antenna coupling network, the antenna coupling network combines the first signal and a second signal received from the antenna and transmits a third signal to the second filter.

Abstract: A device may retrieve a ring tone, an image, and a visual effect from a database based on a client line identifier. In addition, the device may generate frequency samples based on the ring tone, may transform the image based on the frequency samples and the visual effect, and may display the transformed image.

Abstract: An apparatus for repeating signals includes a receive antenna for capturing a receive signal, processing circuitry for processing the receive signal to form a repeated signal, and a transmit antenna for transmitting the repeated signal. The processing circuitry includes gain circuitry for gain in the repeated signal and decorrelation circuitry configured for modifying the repeated signal with respect to the receive signal to thereby decorrelate the repeated signal from the receive signal. The processing circuitry further comprises circuitry configured for calculating a gain margin for the apparatus utilizing the decorrelated receive and repeated signals.

Abstract: Embodiments of the present invention recite an improved signal receiver circuit and a method of implementation. In one embodiment, a first signal pathway of a low-noise block feedhorn comprises a ceramic low-pass filter coupled with a first polarity signal input. In accordance with embodiments of the present invention, a second signal pathway of the low-noise block feedhorn comprises ceramic high-pass filter coupled with a second polarity signal input.

Abstract: Systems and methods are disclosed for the co-location of radio frequency (RF) antennas in portable devices, portable devices and their docking stations and related systems, and devices with restrictive space constraints to allow for simultaneous receive (RX) and transmit (TX) operation without degradation. The systems and methods disclosed overcome RX channel degradation, receiver performance, and other problems seen in prior solutions. More particularly, transmit and receive antennas are oriented to provide for cross-polarization of their electro-magnetic fields, are oriented to allow one or both antenna to fall within null regions of the other antenna, and/or oriented with both cross-polarization and null region considerations in mind. Other variations and implementations are also described.

Abstract: A wireless communication system enabling multihop communication while maintaining the system throughput and preventing degradation of the user throughput. In the system, a BS (base station) determines the relaying method (whether an RS performs reproduction relay or nonreproduction relay) of the RS (relaying station) and the MCS of multihop communication according to the reception quality (the line quality among an MS2, the RS, and the BS) of the pilot for nonreproduction relay, the reception quality (the line quality between the RS and the BS) of the pilot 2 for reproduction relay, and the line quality (the line quality between the MS2 and the RS) measured at the RS. The determination result is transmitted as relay information to the RS and to the MS2 (a mobile station (2)) through the RS. The MS2 encodes and modulates the uplink data with the MCS based on the relay information and transmits the data to the RS.

Abstract: A relaying method and system in a communication system having a Base Station (BS), a Mobile Station (MS) for communicating with the BS, and a Relay Station (RS) for relaying signals between the BS and the MS are provided. In the relaying method and system, the BS generates a BS pilot sequence and transmits the generated BS pilot sequence to the RS. wherein a partial cross correlation between the BS pilot sequence and an RS pilot sequence, being the BS pilot sequence relayed by the RS is always ‘0’. Accordingly, system capacity is more efficiently utilized.

Abstract: A method and apparatus for determining whether a received signal is transmitted via a repeater is described. A source signal to be conveyed via a particular repeater may include, or be modified to include, a variety of signal characteristics having a predictable relationship that remains relatively constant, which may be taken together as a signature of the repeater. The signature may reflect a composite of distinct signals. A database of repeater signature references may be developed, and an adequate match between characteristics of an unknown received signal and such signature references indicates that at least part of the unknown signal is transmitted via a repeater. Useful signal characteristics for repeater signatures may include some representative of signal strength, and time of arrival information, among many other possibilities.

Abstract: Disclosed is an apparatus and method for cooperative reception diversity based on signal point rearrangement or superposition modulation in a relay system, the method includes receiving a superposition-modulated symbol from a transmitting unit, demodulating the received symbol and decoding the demodulated symbol, modulating the received symbol using superposition modulation different from the superposition modulation used in the transmitting unit, and then relaying the modulated symbol to a reception unit, calculating an LLR of the symbol when a certain superposition-modulated symbol is received from a transmitting unit, calculating an LLR of a symbol modulated using superposition modulation different from the superposition modulation used in the transmitting unit when the symbol modulated using the different superposition modulation is received from a relay station, and summing and combining an LLR of each symbol received through the transmitting unit and relay station.

Abstract: A system and method for converting a polyphonic note-based audio object to a Pulse Code Modulated (PCM) audio format is disclosed. An electronic communication device includes a memory containing a polyphonic note-based audio object containing at least two notes which overlap in at least some time interval and a lookup table containing trigonometric function evaluations. The polyphonic note-based audio object contains note frequency information. The polyphonic note-based audio object is converted to a PCM stream by generating PCM code words for each sample point in the PCM stream based upon the polyphonic note frequency information. The PCM code words are determined based upon selection of one or more of the trigonometric function evaluations within the look-up table. A speaker outputs audio based upon the PCM formatted stream.

Abstract: Embodiments of the invention provide methods for optimizing the spectral efficiency of control channel transmissions carrying scheduling assignments from a serving Node B to user equipments. This is accomplished through the selection of the modulation and coding scheme with the highest spectral efficiency that can support transmission of a scheduling assignment to the corresponding user equipment with a reception performance satisfying a target error rate.

Abstract: In this present invention, MP3 playing and charging system having an adapter for installing MP3 and dynamic speakers which includes a docking station and two speakers that can be used in attached or separated manner; two speakers that allow variation of speaker direction generating dynamic sound when attached; and a docking station that can be attached and connected to MP3 player with the use of MP3 installing adapter when connecting MP3 to the docking station is provided.

Abstract: Provided is a mobile communication system which includes a plurality of RAT (Radio Access Technology) and can eliminate the need of a control channel for reporting RAT information so as to prevent congestion or shortage of the control channel capacity. In the mobile communication system, an LTE relay station (30) has a cover area (31) identical to a cover area (21) owned by a WLAN host station (20) and relays/transmits the signal received from an LTE base station (10) to a mobile station (40) in the cover area (31). The LTE relay station (30) adds to the signal received from the LTE base station (10), one of the offsets: a frequency offset, a time offset, and a power offset as information indicating that the mobile station (40) which receives a relay signal from the local station is located in the cover area (21) of WLAN and transmits the signal after offset addition to the mobile station (40) located in the cover area (31) (i.e., the cover area (21)).

Abstract: A quadrature frequency division multiplexing (“OFDM”) wireless receiver, including methods and devices for adaptive quantization of OFDM signals according to modulation and coding schemes and sub-carrier frequency responses, is provided. Efficient quantization may be utilized to reduce the large dynamic range of signals to achieve circuit simplification and chip area reduction. In one embodiment, a quantization circuit includes a quantization selector to select quantization thresholds according to modulation and coding schemes and sub-carrier frequency responses, and a non-uniform quantizer to reduce input dynamic range so that an output is represented by fewer bits than an input.

Abstract: Provided are an on-channel repeater and a method thereof. The repeater receives signals on one channel and distributes the signals on the same channel by converting RF signals from a main transmitter into baseband signals; equalizing them in a high-performance equalizer, adding a repeater identifier to them; modulating the baseband signals with the repeater identifier into RF signals. The repeater includes: a receiver for receiving RF signals; a demodulator for demodulating the RF signals into baseband signals; an equalizer for equalizing the baseband signals; an adder for adding a repeater identifier to the baseband signals; a modulator for modulating the baseband signals with the repeater identifier added in the adder into RF signals; and a transmitter for transmitting the RF signals modulated in the modulator. The technology of the present invention is used to form an on-channel repeating network in an arbitrary transmission system including a digital television broadcasting system.

Abstract: A method and system for allocating data bursts in a wireless communication system. The system has a frame set by a symbol interval axis and a frequency band axis. The frame includes a first region in which a MAP message is transmitted and a second region to which the data bursts are allocated. A third region based on a symbol interval and a frequency band is set in the second region. The data bursts are sequentially allocated to the third region from a first symbol interval along the frequency band axis.

Abstract: An electron source excellent in the uniformity in current emission distribution is provided certainly and at a low cost. A process for producing an electron source having an electron emitting portion at one end of a rod, which comprises a step of forming the electron emitting portion by machining, and a step of removing a damaged layer at the surface of the formed electron emitting portion by chemical polishing or electrolytic polishing.

Abstract: The present invention is a novel device, system, and method for determining the damped natural frequencies of a dynamic system whose characteristics are available in the form of a “frequency response function” FRF. According to an exemplary embodiment of the present invention, the method identifies the dampened natural frequencies associated with the poles and zeros of a transfer function. The method is especially useful for analysis of measurements that contain some degree of contamination due to noise or non-linear effects. It is based on a set of rules that may be more successful than a direct approach based on a least squares criteria.

Abstract: In a radio communication system, transmitter and receiver stations share information on a maximum number of bits communicated per symbol. The transmitter station encodes a signal with sufficient error correcting capabilities to create a codeword. The transmitter station allocates the bits from the codeword to each symbol, modulates the symbols using a modulation type which processes symbols each having a number of bits equal to or smaller than the maximum number of bits per symbol, and transmits the modulated symbols. The receiver station demodulates the symbols using a modulation type which processes a larger number of bits per symbol as the transmission path quality is higher from among modulation types which process symbols having a number of bits equal to or smaller than the maximum number of bits per symbol.

Abstract: A wireless communication device having extremely simple constitution is used, and a low-cost and low power consumption wireless network system with high-quality signals is provided. The wireless network system comprises a plurality of wireless communication devices (101) each comprising a radiating oscillator (1) configured to integrate a transistor into a microwave oscillating resonator to generate a negative resistance and to commonly use a function of an antenna (11), an intermediate frequency signal generating section (4) and a receiving signal detecting section (7).

Abstract: A dual-use PLL frequency synthesizer for use in a transceiver is capable of operating as a local oscillation generator in a receiving mode and as a transmitter in a transmitting mode. The PLL frequency synthesizer includes a digital processor, a Digital-to-Analog Converter (DAC), a low pass filter and a phase locked loop. The digital processor generates a digital signal, in which the digital signal is a modulated digital signal in the transmitting mode, and the digital signal is a reference digital signal in the receiving mode. The DAC converts the digital signal to an analog signal, and the low pass filter filters the analog signal to produce a filtered analog signal. The phase locked loop up-converts the filtered analog signal to an RF signal. In the transmitting mode, the RF signal is a modulated RF signal, and in the receiving mode, the RF signal is a reference RF signal.

Abstract: An FM modulator measuring an f-V characteristic of a voltage controlled oscillator in a reduced time period. In the FM modular a characteristic measurement time control section 110 notifies a correction section 108 of a time at which a measurement of the f-V characteristic of a voltage controlled oscillator 103 is to start and a time at which the measurement of the f-V characteristic of the voltage controlled oscillator 103 is to and while a carrier wave frequency is being changed to a predetermined frequency. Thus, the correction section 108 measures the f-V characteristic of the voltage controlled oscillator 103 in a reduced time period.

Abstract: A method and an apparatus are provided for estimating and removing interference of a signal at a wireless repeater operating in a multi-carrier system. In the method, a current echo channel linear prediction coefficient, which represents a coefficient between a current train signal section and a previous train signal section, is estimated using a current echo channel coefficient estimated in the current train signal section and a previous echo channel coefficient generated in the previous train signal section. A next echo channel coefficient is estimated using the current echo channel coefficient, the previous echo channel coefficient, and the current echo channel linear prediction coefficient. An echo channel coefficient outside a train signal section is estimated using the current echo channel coefficient and the next echo channel coefficient.

Abstract: An AM-FM hybrid signal is created which may be used to communicate simultaneously with both RFID tags that receive AM signals and wireless devices that receive FM or PM signals. The AM-FM hybrid signal may be fed back into the system's receiver at the local oscillator in order to recover the RFID tag's FM response, thus enabling simultaneous reception and decoding of both RFID tag FM response and FM wireless device response.