289 results about "Radio receiver design" patented technology

In a signal receiving apparatus as, for example, that used in the monitoring in a stolen vehicle transceiver of the presence of sequential transmitted signals specifically requesting that transceiver to respond to enable tracking the vehicle, wherein the receiver is powered by a consumable energy source of predetermined budgeted lifetime and adapted to operate between quiescent energy-saving and energized energy-consuming states for performing such sequential signal monitoring, desired signal identifying and related functions, a method of and apparatus for insuring the availability of energy to be able to perform such functions within said predetermined budgeted life time, that comprises, allocating budget time intervals for periodically operating the receiver intermittently in energized state to enable the performing of such functions as monitoring for such signals; and, in the event of inordinate energy consumption during such operation, that, if continued, would render the operation out of overall allocated time budget, adaptively skipping time intervals with the receiver quiescent, sufficiently to get the operation back on overall time budget.

Various apparatuses and methods are described to reduce interference in signals subject to intermodulation products and high power narrow band interfering signals on lower power wideband signals. Apparatuses and methods described herein also provide the capability for supporting multi-standards, multi-modes and multi-bands in wireless and wired applications with a single receiver or a receiver with minor variations. The receiver described herein samples the entire band in which there can be signals of interest or signals that can generate interference. All of these signals are sampled in one bit stream and the bit stream is processed to isolate signals of interest and interfering signals. The isolated interfering signals are then cancelled out of the signals of interest.

A method of remotely locating a mobile device equipped with a radio receiver by remotely and securely activating the device's ringer and location system, and communicating such location to the device owner.

A radio receiver (100) has an equalizer (500) that operates in the time domain to remove residual interference that is not removed by an IF filter (200) operating in the frequency domain that is caused by an adjacent interfering FM station. The equalizer (500) includes a modified constant modulus algorithm (CMA) to generate a tap update signal from the output of the equalizer (500). The equalizer (500) uses the modified CMA to reduce an amplitude fluctuation of the received signal caused by the adjacent interfering station. The CMA is modified to use an infinite impulse response (IIR) filter (540) to generate the tap update. The IIR filter (540) also speeds up a convergence of the modified CMA to provide better performance.

A radio receiver includes a first receiver module for converting a first radio frequency (RF) signal at a first carrier frequency into a first baseband signal. A second receiver module converts a second RF signal at a second carrier frequency into a second baseband signal. A recombination module combines the first baseband signal and the second baseband signal into an output signal.

A remotely located radio transceiver system for a mobile communications network is disclosed, comprising a radio transmitter and a radio receiver, and an asynchronous packet-based digital input / output for connecting the remotely located radio transceiver system to at least one digital processing unit. The at least one digital processing unit is adapted to provide digitised signals to, or receive digitised signals from, the remotely located radio transceiver system. A corresponding method for generating a transmit signal comprises receiving, from the at least one digital processing unit, asynchronous packet-based data at the asynchronous packet-based input / output of the remotely located radio transceiver system, and processing the asynchronous packet-based data to form the transmit signal. Another corresponding method for processing a receive signal is also disclosed.

A radio receiver is described that processes multiple wireless standards using a single antenna according to embodiments of the invention. The radio receiver includes a single antenna, and a low noise amplifier that is connected to the antenna, without an intervening power divider or power splitter. The output of the low noise amplifier feeds multiple wireless receivers in a parallel arrangement that are operating according to different communications standards, including for example a Bluetooth receiver, and a WLAN 802.11 receiver. Additional wireless standards and their corresponding receivers could be added as well. The input impedance of the low noise amplifier defines the impedance seen by the antenna, regardless of which operational standard is actually in use. Since the input impedance of the low noise amplifier is substantially independent of whether the Bluetooth or WLAN paths are ON or OFF, simultaneous operation can be accomplished.

A system, method, and receiver for receiving radio signals modulated according to different radio communication standards. Radio signals are received and downconverted to an intermediate frequency (IF) signal. An A / D-converter samples the IF signal at a sampling rate and digitizes the sampled signal into a digital signal. A channelizer filters out at least two modulated channels from the digital signal. A first ago channel is modulated according to a Time Division Multiple Access (TDMA) standard, and a second channel is modulated according to a Code Division Multiple Access (CDMA) standard. A first demodulating unit demodulates the TDMA channel, and a second demodulating unit demodulates the CDMA channel. Each of the demodulating units detects and, when needed, resamples each of the modulated channels individually, and delivers a corresponding demodulated channel. A Frequency Division Multiple Access (FDMA) channel may also be received and processed.

An interference rejection algorithm for a radio receiver is presented. According to the present solution a signal comprising a training sequence and a data sequence is received at the radio receiver. A radio channel response may be estimated from the received training sequence, and interference parameters may be estimated from at least one of the received training sequence and the received data sequence, the estimation of the interference parameters comprising smoothing a frequency spectrum of at least one of the estimated channel response and the estimated interference parameters through averaging. Then, frequency domain interference suppression weights are calculated from the estimated channel response and the interference parameters, and weighting of the received data sequence is carried out with the calculated weights.

Operating a radio receiver can include identifying a set of stations that broadcast a radio program using different frequencies or different transmission protocols at substantially the same time. Broadcast signal strength, or some other signal quality metric, of broadcast signals from the stations can be evaluated, and the radio receiver can be tuned to one of the stations in the set of stations based on the evaluation.

A method and apparatus for scheduling virtual upstream channels within one physical upstream channel is disclosed. A different MAP message is received by a receiver for each virtual upstream channel from that sent downstream. Where multiple upstream receivers are used, separate MAP messages can be sent for each receiver and consequently, each virtual upstream channel. The use of multiple upstream receivers is not necessary if the upstream receiver can change the upstream channel descriptors it is using per burst.

The present invention relates to a radio receiver and a method of amplifying a signal in the same. The apparatus comprises a receiving system capable of receiving a radio signal according to plural types of radio communication systems while this receiving system is provided with amplifiers adapted for amplifying plural types of received signals to amplify received signals according to the plural types of radio communication systems to carry out an optimal amplifying process relative to the signal for each radio communication system. As a result, the power consumption may be reduced.

A radio receiver includes a power control module for selectively powering down and powering up radio receiver elements in between known communication periods according to one aspect of the present invention. According to a second aspect of the invention, the radio receiver operates in a low power mode of operation and periodically “sniffs” to determine whether an access point has messages or communication signals to transmit to it.

There is disclosed a system for inputting speech that comprises an echo canceller section 120 for subtracting a pseudo echo signal, generated by an adaptive filter 121 based on a speech signal inputted to a first input terminal 120a, from a speech signal for sending as inputted to a second input terminal 120b to thereby remove echo components contained in the speech signal for sending; a main microphone 151 for mainly receiving sound from an objective sound source; a reference microphone 152 disposed a predetermined distance apart from the main microphone 151 for mainly receiving sound from other than the objective sound source; and an audio delay section 180 for giving a predetermine delay to the speech signal for sending from the main microphone 151. The speech signal from the reference microphone 152 is inputted to the first input terminal 120a of the echo canceller section 120, while the speech signal for sending which is from the main microphone 151 and to which the delay has been given in the audio delay section 180 is inputted to the second input terminal 120b of the echo canceller section 120. The delay at the audio delay section 180 is adjusted within a range of delay time of the echo components which the echo canceller section 120 removes. According to this speech input system, the noise is well removed regardless of directions of the sources of the objective sound and the noise, regardless of the difference in level between the objective sound and the noise and / or regardless of whether the noise abruptly changes its tone or volume, so that a clear speech input is achieved even in such a condition that there is noise in the surrounding environment.

Even if a receiver has a normal gain and a lowered intermodulation distortion characteristics, a fault detection is possible. A test signal transmitter sends a test signal having at least two frequencies to a radio receiver through a coupler. A digital signal processing section receives a signal which includes an IM3 component generated by the radio receiver and measures the electric power of fundamental wave components and the IM3 component. Then, the digital signal processing section calculates the gain of the radio receiver and IIP3, which is an index for intermodulation distortion characteristics, of the radio receiver 207 from the calculated electric power. A base station control section determines whether the gain and IIP3 of the radio receiver fall in predetermined ranges to determine whether the radio receiver works normally or has a fault.

A method of controlling a low power radio receiver including controlling the radio receiver for a first, relatively short, period of time to detect radio transmissions in a predetermined frequency band, and determining whether to control the radio receiver for a subsequent second relatively longer period of time to receive data from a subsequent radio transmission in the predetermined frequency band.

A radio receiver for a digital cellular system or the like which transmits or receives, for example, voice signals by coding them, and easily and reliably detects a synchronizing signal. A synchronizing signal FCCH is detected by converting a base band converted transmitted signal with an analog-to-digital convertor circuit 17, and then by detecting a correlation value with a predetermined reference signal.

A receiver contains a demodulator system that can derive an analog audio signal and compressed digital data from radio frequency signal. The receiver also contains a decompressor that can decompress the compressed digital data into uncompressed form. A digital to analog converter is used to convert the uncompressed digital data into another analog signal. Control logic is used to allow a user to select either the demodulated analog audio signal or the converted analog signal. The selected signal is delivered to an output device, such as a loudspeaker.

A monitoring system includes a user unit and a base station. The user unit includes a radio beacon that transmits a radio signal identifying a particular user. The base station includes a radio receiver that receives the radio signal, a processor that formats the received radio signal for display on an output device, and an output device that displays an indication of reception of the radio signal and an indication of the identity of the user. The user unit can also include a sensor interface that receives an output signal from a sensor device, and a processor that formats the sensor device output signal for transmission by the radio beacon as a component of the radio signal. The base station processor can also format the received radio signal for display on the output device such that the content of the sensor device output signal is displayed.

A radio receiver includes a branching unit, a first gain-control system, a second-gain control system, and a signal processing unit. The branching unit branches a radio signal received by the radio receiver into two signals. The first-gain control system performs a gain control of a pilot signal in one of branched signals, and the second gain control system performs a gain control of a data signal in another of the branched signals. The signal processing unit synchronizes frames in the received radio signal. The signal processing unit outputs a gain signal to each of the first gain-control system and the second gain-control system. The first gain-control system and the second gain-control system perform the gain controls based on the gain signal.

A method of fast acquisition of a location of a device is disclosed. The method generally includes the steps of (A) repeatedly powering up automatically (i) a radio receiver and (ii) a given subset of a plurality of correlators in some of a plurality of search engines in the device, (B) buffering first data of a plurality of position signals received through the radio receiver over a first period, each of the position signals comprising a respective one of a plurality of code sequences, (C) searching through the first data with the correlators to find at least one of the code sequences, each of the correlators using a search window comprising a fraction of a code length of the code sequences and (D) generating an output signal carrying a location of the device based on the position signals corresponding to the code sequences that were found.