16004 results about "Baseband" patented technology

A sensor interface is configured to receive a sensor signal. A transmitter modulates a first baseband signal responsive to the sensor signal so as to generate a transmit signal. A receiver demodulates a receive signal corresponding to the transmit signal so as to generate a second baseband signal corresponding to the first baseband signal. Further, a monitor interface is configured to communicate a waveform responsive to the second baseband signal to a sensor port of a monitor. The waveform is adapted to the monitor so that measurements derived by the monitor from the waveform are generally equivalent to measurements derivable from the sensor signal. The communications adapter may further comprise a signal processor having an input in communications with the sensor interface, where the signal processor is operable to derive a parameter responsive to the sensor signal and where the first baseband signal is responsive to the parameter. The parameter may correspond to at least one of a measured oxygen saturation and a pulse rate.

Carrier Interferometry (CI) provides wideband transmission protocols with frequency-band selectivity to improve interference rejection, reduce multipath fading, and enable operation across non-continuous frequency bands. Direct-sequence protocols, such as DS-CDMA, are provided with CI to greatly improve performance and reduce transceiver complexity. CI introduces families of orthogonal polyphase codes that can be used for channel coding, spreading, and / or multiple access. Unlike conventional DS-CDMA, CI coding is not necessary for energy spreading because a set of CI carriers has an inherently wide aggregate bandwidth. Instead, CI codes are used for channelization, energy smoothing in the frequency domain, and interference suppression. CI-based ultra-wideband protocols are implemented via frequency-domain processing to reduce synchronization problems, transceiver complexity, and poor multipath performance of conventional ultra-wideband systems. CI allows wideband protocols to be implemented with space-frequency processing and other array-processing techniques to provide either or both diversity combining and sub-space processing. CI also enables spatial processing without antenna arrays. Even the bandwidth efficiency of multicarrier protocols is greatly enhanced with CI. CI-based wavelets avoid time and frequency resolution trade-offs associated with conventional wavelet processing. CI-based Fourier transforms eliminate all multiplications, which greatly simplifies multi-frequency processing. The quantum-wave principles of CI improve all types of baseband and radio processing.

A device, network and method wherein a standard wireless modem is coupled to wiring for carrying a wireless baseband signal that may be OFDM based, and may be directly generated by the wireless IF modem, or extracted from the modem RF signal. The wiring may be a building utility wiring, such as telephone, AC power or CATV wiring. The baseband signal is carried simultaneously with the utility service signal over the utility wiring using Frequency Division Multiplexing. The device may be enclosed with a data unit, a standalone dedicated enclosure, within an outlet or as a plug-in outlet adapter. Data units may couple the device by a wiring port such as standard data connector, or via wireless connection. The device may be locally powered or via a power signal carried over the wiring. This abstract is not intended to limit or construe the scope of the claims.

An audio signal is conveyed more efficiently by transmitting or recording a baseband of the signal with an estimated spectral envelope and a noise-blending parameter derived from a measure of the signal's noise-like quality. The signal is reconstructed by translating spectral components of the baseband signal to frequencies outside the baseband, adjusting phase of the regenerated components to maintain phase coherency, adjusting spectral shape according to the estimated spectral envelope, and adding noise according to the noise-blending parameter. Preferably, the transmitted or recorded signal also includes an estimated temporal envelope that is used to adjust the temporal shape of the reconstructed signal.

A centralized base station system based on ATCA, comprising a main base station subsystem and one or more remote radio frequency subsystems, the main base station subsystem comprising: one or more shelves based on ATCA platform, each shelf comprising at least one control switch module of ATCA board form; one or more base station controller interface module; a signaling module; one or more baseband processing modules; one or more remote radio frequency interface modules; a first switch network comprising first switch network shelf back board BASE interface link, a control switch module and a first network switch unit; a second switch network comprising a shelf back board FABRIC interface link, a control switch module and a second network switch unit; a clock synchronization network comprising a shelf back board clock synchronization bus, a control switch module and a clock unit; and a signal transmission network, wherein the second network switch unit and the clock unit are further connected to the first network switch unit, one of the control switch modules of all the shelves is the main control module.

A method is provided for communicating signals at a low power level in an electromagnetic interference (EMI) environment. A first device transmits a modulated signal having a first carrier frequency, including the encoded information via a hardwire transmission medium. In one aspect, the power level of the modulated signal can be adjusted to minimize power consumption or reduce the generation of EMI. The modulated signal may be in one of the following formats: frequency modulation (FM) or phase modulation (PM) to name a few examples. A second device including a logarithmic detector amplifier (LDA) demodulator circuit receives the signal, which may be mixed with EMI. The LDA demodulator circuit amplifies the modulated signal, without amplifying the EMI, to supply a demodulated baseband signal, which may be an n-ary digital signal, or an audio signal. A low-power, noise insensitive communication channel is also provided.

Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal are described herein. Briefly stated, such methods, systems, and apparatuses operate by receiving an EM signal and an aliasing signal having an aliasing rate. The EM signal is aliased according to the aliasing signal to down-convert the EM signal. The term aliasing, as used herein, refers to both down-converting an EM signal by under-sampling the EM signal at an aliasing rate, and down-converting an EM signal by transferring energy from the EM signal at the aliasing rate. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a demodulated baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

A transceiver includes a transmitter and a homodyne receiver, wherein the receiver is used to process both antenna-received and antenna-reflected signals. Thus, during a receive mode, for example, the receiver downconverts antenna-received signals to baseband signals, which are then processed to recover receive signal information. Then, during a transmit mode for example, antenna-reflected transmit signals are fed back to the receiver, which is retuned to the desired transmit frequency, and thus downconverts the reflected transmit signals to baseband signals. These baseband signals are then processed to obtain a characterization of impedance mismatch between the transceiver's transmitter and the associated antenna. An adjustable matching network disposed in the transmit signal path thus may be adjusted based on the characterization to reduce the mismatch. Such configurations may be used with either single-band or multi-band embodiments of the transceiver, and the transceiver may be used in both TDMA and CDMA communication systems.

The invention relates to pulsed oximeters used to measure blood oxygenation. The current trend towards mobile oximeters has brought the problem of how to minimize power consumption without compromising on the performance of the device. To tackle this problem, the present invention provides a method for controlling optical power in a pulse oximeter. The signal-to-noise ratio of the received baseband signal is monitored, and the duty cycle of the driving pulses is controlled in dependence on the monitored signal-to-noise ratio, preferably so that the optical power is minimized within the confines of a predetermined lower threshold set for the signal-to-noise ratio. In this way the optical power is made dependent on the perfusion level of the subject, whereby the power can be controlled to a level which does not exceed that needed for the subject.

Exemplary embodiments of system and method are provided for measuring signal amplitude, phase and / or delay offsets between multiple transmit signals fed through the transmit signal processing chains and wirelessly transmitted over the transceive antennas of separate transceiver modules, wherein transmit signal coupling between the transmit antennas of said transceiver modules' transmit signal processing chains may be used for synchronizing the transmit signals and calibrating their amplitude, phase and / or delay parameters. The exemplary embodiments further provide a front end arrangement of a wireless transceiver device which can comprise at least two independently controllable transceiver modules, each connected to an associated spatial diversity transceive antenna and comprising at least one associated transmit signal processing chain and at least one associated receive signal processing chain coupled to a common baseband processing unit. The exemplary transceiver architecture can be executed on an antenna loop between the transmit signal processing chain of a first transceiver module and the transmit signal processing chain of a second transceiver over the air interface and relies on an adaptive antenna concept which facilitates a wireless transmission of data via a plurality of wireless communication channels utilizing an array of transceive antennas, receiving feedback information via at least one of said communication channels using such antenna loop and modifying a transmission mode based on the received feedback information.

An efficient method for compressing sampled analog signals in real time, without loss, or at a user-specified rate or distortion level, is described. The present invention is particularly effective for compressing and decompressing high-speed, bandlimited analog signals that are not appropriately or effectively compressed by prior art speech, audio, image, and video compression algorithms due to various limitations of such prior art compression solutions. The present invention's preprocessor apparatus measures one or more signal parameters and, under program control, appropriately modifies the preprocessor input signal to create one or more preprocessor output signals that are more effectively compressed by a follow-on compressor. In many instances, the follow-on compressor operates most effectively when its input signal is at baseband. The compressor creates a stream of compressed data tokens and compression control parameters that represent the original sampled input signal using fewer bits. The decompression subsystem uses a decompressor to decompress the stream of compressed data tokens and compression control parameters. After decompression, the decompressor output signal is processed by a post-processor, which reverses the operations of the preprocessor during compression, generating a postprocessed signal that exactly matches (during lossless compression) or approximates (during lossy compression) the original sampled input signal. Parallel processing implementations of both the compression and decompression subsystems are described that can operate at higher sampling rates when compared to the sampling rates of a single compression or decompression subsystem. In addition to providing the benefits of real-time compression and decompression to a new, general class of sampled data users who previously could not obtain benefits from compression, the present invention also enhances the performance of test and measurement equipment (oscilloscopes, signal generators, spectrum analyzers, logic analyzers, etc.), busses and networks carrying sampled data, and data converters (A / D and D / A converters).

A transmitter and corresponding method for transmitting an OFDM signal in a communications channel, including a plurality of base-band OFDM modulators, each for modulating a respective data signal onto a plurality of orthogonal sub-carriers and outputting a respective sub-channel OFDM signal; and a fast convolution filter and up-converter for applying fast convolution filtering and digital up-conversion to the sub-channel OFDM signals to output a combined OFDM signal that includes each of the sub-channel OFDM signals, the fast convolution and up-converter filtering each of the sub-channel OFDM signals and frequency shifting all of the sub-channel signals to respective designated frequencies within the combined OFDM signal. A corresponding receiver is also provided.

A radio frequency (RF) transmitter includes a baseband processing module, an up conversion module, a power amplifier module, and an antenna assembly. The baseband processing module is coupled to convert outbound data into a first outbound symbol stream and a second outbound symbol stream and to generate an adjust signal. The up conversion module is coupled to convert the first outbound symbol stream into a first up converted signal and to convert the second outbound symbol stream into a second up converted signal. The power amplifier module is coupled to amplify the first and second up converted signals to produce first and second outbound RF signals. The antenna assembly is coupled to transmit the first and second outbound RF signals, wherein the antenna assembly adjusts at least one of amplitude and phase of at least one of the first and second outbound RF signals based on the adjust signal.

Disclosed is a method for using various multiple antenna schemes in a baseband wireless access system is provided. According to the method, a downlink MAP message is constructed in order to support various multiple antenna schemes based on a multiple-input multiple output (MIMO), which is one of the multiple antenna schemes, so that compatibility with exiting MIMO technology having no MIMO feedback can be achieved and overhead occurring in transmission of an MAP information element can be reduced. Further, it is possible to efficiently support spatial multiplexing technology capable of transmitting multiple layers having different modulation and coding in a MIMO system.

Disclosed herein is a dual SIM terminal and an operating method thereof for supporting dual standby and single talk using a single baseband. The dual SIM mobile terminal may include a controller which is a single chipset, a dual SIM, and two radio frequency (RF) units, thereby having an effect capable of providing a service at the same level as a dual SIM using two mobile terminals even with one mobile terminal. Furthermore, dual SIM switching is performed according to a state of the network, a pricing system, and a user's setting, thereby providing the user's desired service.

A transceiver employing a steerable phased-array antenna includes a modem architecture in which signals from each antenna element in the array are independently processed down to the individual baseband channel level, and digital beamforming is performed at baseband. The data rate reduction from IF to baseband permits parallel signal data from multiple antenna elements to be time multiplexed and serially processed at acceptable data rates at baseband with minimal modem hardware requirements. Both for transmit signal modulation and received signal demodulation, the computation of carrier tracking, automatic gain control (AGC) / power-control, and beamforming are shared by the same processing circuitry for all channels when performed at baseband. The resulting baseband circuitry is only incrementally larger than that required for carrier tracking and AGC alone, yet accomplishes independent beamforming for each antenna element on each user channel.

A method and apparatus are disclosed for a wireless communication device to simultaneously receive at least two signals. Two receiver portions are provided in the wireless communication device. A first receiver portion is configured to receive a first communication signal. A second receiver portion is configured to receive a second communication signal. The two receiver portions are configured to convert the first and second communication signals to a common frequency band. The common frequency band may be an intermediate frequency band or baseband frequency band. The converted first and second communication signals are combined in the common frequency band using an adder or other signal combiner. The combined signal is processed in a single signal processor. The communication device is able to resolve each of the received signals when the first communication signal is a narrowband signal and the second communication signal is a wideband signal, such as a spread spectrum signal.

A device, network and method wherein a standard wireless modem is coupled to wiring for carrying a wireless baseband signal that may be OFDM based, and may be directly generated by the wireless IF modem, or extracted from the modem RF signal. The wiring may be a building utility wiring, such as telephone, AC power or CATV wiring. The baseband signal is carried simultaneously with the utility service signal over the utility wiring using Frequency Division Multiplexing. The device may be enclosed with a data unit, a standalone dedicated enclosure, within an outlet or as a plug-in outlet adapter. Data units may couple the device by a wiring port such as standard data connector, or via wireless connection. The device may be locally powered or via a power signal carried over the wiring. This abstract is not intended to limit or construe the scope of the claims.

Integrated wired and wireless wavelength division multiplexing passive optical network (WDM PON) apparatus using a light source mode-locked to fed incoherent light includes: a fed light generator for providing fed light for up / downstream signals via a broadband light source emitting an incoherent optical signal; a central office (CO) for receiving, mode-locking, and downstream-optical-transmitting the incoherent optical signal generated by the fed light generator and receiving and optical-detecting an upstream optical signal transmitted from a subscriber unit; and the subscriber unit for receiving, mode-locking, and upstream-optical-transmitting the incoherent optical signal generated by the fed light generator and receiving and optical-detecting a downstream optical signal transmitted from the CO, wherein a wired optical transmitter for transmitting a baseband wired signal and a wireless optical transmitter for transmitting a high frequency radio frequency (RF) signal are comprised for up / downstream optical transmission of the CO and the subscriber unit.

A novel mechanism for simultaneous multiple signal reception and transmission using frequency multiplexing and shared processing. Multiple RF signals, which may be of various wireless standards, are received using one or more shared processing blocks thereby significantly reducing chip space and power requirements. Shared components include local oscillators, analog to digital converters, digital RX processing and digital baseband processing. In operation, multiple RX front end circuits, one for each desired wireless signal, generate a plurality of IF signals that are frequency multiplexed and combined to create a single combined IF signal. The combined IF signal is processed by a shared processing block. Digital baseband processing is performed on each receive signal to generate respective data outputs. Further, simultaneous full-duplex transmission and reception is performed using a single local oscillator. The phase / frequency modulation of the frequency synthesizer used in the TX is removed from the local oscillator signal for use in the receiver.

A wireless radio for wireless networking communication systems includes a radio frequency (RF) transceiver integrated circuit (IC) and a baseband digital signal processing (DSP) IC. A bidirectional serial digital interface couples data between the RF transceiver IC and the DSP IC to provide a high data rate and low noise. The bidirectional serial digital interface includes a first serial data connection and a second serial data connection. In one embodiment, the RF transceiver IC has a single bit sigma delta A / D modulator to convert an analog signal into a first serial digital bit stream for communication over the first serial data connection. In one embodiment, the DSP IC has a single bit sigma delta digital modulator to generate a second serial digital bit stream for communication over the second serial data connection.

Emergency Location Transceivers (ELT) and communication transceivers (transmitters and receivers) for reception and demodulation of location finder signals, Global Positioning System (GPS) satellite signals and non GPS satellite location finder and other location finder signals. The received location finder signals are demodulated to location finder baseband signals. Baseband signal processors for processing single or a plurality of input signals for providing Orthogonal Frequency Division Multiplex (OFDM) baseband signals, filtered signals, cross-correlated shaped in-phase and quadrature-phase baseband signals and spread spectrum signals. Signal modulators for modulating the processed signals and for providing the modulated signals to the signal transmitter for transmission of the modulated signals. Emergency receiver systems for reception, demodulation and processing of the modulated transmitted signals. Certain emergency receiver embodiments, such as receivers of calls made to emergency call number 911 contain two or more receive antennas for reception and processing of the transmitted modulated signal. In certain embodiments emergency receiver systems have two or more receive antennas operated in a diversity mode, for reception and processing of the transmitted modulated signal.