260 results about "Analog transmission" patented technology

A dynamic signature creation and enforcement system can comprise a tap configured to copy network data from a communication network, and a controller coupled to the tap. The controller is configured to receive the copy of the network data from the tap, analyze the copy of the network data with a heuristic to determine if the network data is suspicious, flag the network data as suspicious based on the heuristic determination, simulate transmission of the network data to a destination device to identify unauthorized activity, generate an unauthorized activity signature based on the identification, and transmit the unauthorized activity signature to a digital device configured to enforce the unauthorized activity signature.

The present invention provides a system and method for multi-path simulation that employs a shielded anechoic chamber to avoid external electromagnetic interference and other uncontrollable transmission paths during testing, and simulates a main indirect transmission path by a reflector within the chamber. An attenuating device is used to attenuate signals, thereby simulating the signal attenuation during transmission. The shielded anechoic chamber also includes a movable platform and a turntable, both controlled by a control unit, for carrying a dipole antenna and a wireless communication device to be tested respectively. The movable platform is used to shift the antenna, thereby simulating the phase shift between a direct path and a main indirect path of the system; the turntable is used to change the reception azimuth of the communication device, thereby measuring the performance of the device in various azimuth angles.

An RF-lightwave transmitter performs successive conversions of an information-bearing input signal in order to generate an output signal suitable for transmission in a wireless communications system. The transmitter includes a high-efficiency FM laser connected to a FM discriminator. In operation, the laser converts an RF signal into a frequency-modulated optical signal, and the discriminator converts this signal into an amplitude-modulated optical signal. The discriminator performs its conversion using a high slope-efficiency linear transfer function which ensures that the AM optical signal varies in accordance with a desired operational performance. The transmitter also includes a photodiode which converts the AM signal output from the optical discriminator back into an RF signal for transmission. Experimental results demonstrated that a transmitter of this type is able to realize greater than 10 dB RF insertion gain at less than 0 dBm optical power, with a high spurious-free dynamic range and low noise. A signal processor embodied within the transmitter may be used in a purely optical communication systems or may be used for other types of RF-photonics applications such as those expected for use in next-generation systems.

A method and an apparatus determine an analog beam in a digital/analog hybrid beam-forming system. In a method of a reception end, for determining an analog beam in a hybrid beam-forming system, channel information regarding a transmission end is measured. At least one of an analog transmission beam-forming vector and a reception beam-forming vector is determined depending on the measured channel and a digital beam-forming technique in use. Information of the determined transmission beam-forming vector is fed back to the transmission end.

A radio relay apparatus and an operating method therefor are provided.

The radio relay apparatus that relays a communication signal between a base station and a terminal includes a donor unit that transmits and receives a radio frequency signal to and from the base station, and at least one service unit that transmits and receives an analog transmission signal to and from the donor unit, and transmits and receives the radio frequency signal to and from the terminal. In the analog transmission signal, an intermediate frequency signal into which the radio frequency signal is converted and a time synchronization signal extracted from the intermediate frequency signal are combined. The time synchronization signal is used by the donor unit and the at least one service unit for time division duplex communication (TDD) synchronization control.

A system for and method of transmitting and storing data using multidecimal encoding. A binary data stream is encoded into a multidecimal data stream. Distinct frequencies are then assigned to characters in the multidecimal data stream for transmitting the multidecimal character information. Individual frequencies, or combinations of frequencies, may be assigned to each multidecimal character to be transmitted, through various methods. The various multidecimal transmission schemes described herein may be employed in any of several transmission systems, such as fiber optics networks, analog transmission systems, DSL systems, cable modem systems, wireless communication systems, or any other suitable data transmission systems. Multidecimal data may also be stored in various storage media, such as CD-ROMs, DVDs, or RAM.

A wireless communication apparatus utilizing an orthogonal frequency division multiplexing communication method includes an antenna transmitting and receives a radio-frequency signal; a receiver frequency converter frequency-converting the radio-frequency signal into a baseband signal in accordance with a low-intermediate frequency method; an analog-to-digital converter converting the baseband signal into a digital signal; an orthogonal frequency division multiplexing demodulator acquiring a plurality of subcarriers in a frequency domain; a data reproduction unit reproducing data; a transmission data generator generating transmission data; an orthogonal frequency division multiplexing modulator performing orthogonal frequency division multiplexing modulation of the plurality of subcarriers; a digital-to-analog converter converting the digital orthogonal frequency division multiplexing signal into an analog signal; and a transmitter frequency converter converting the analog transmission baseband signal into a transmission radio-frequency signal in accordance with a zero-intermediate frequency method.

A method for analyzing response values sum of differential signals includes: receiving configurations of simulation parameters; simulating differential signal paths with an analog transmission channel according to a design file; analyzing the analog transmission channel into different channel modes according to received configurations; simulating a plurality of pulse signals into the analog transmission channel according to the received configurations, and recording an impulse response of each of the channel modes; simulating differential signal transmissions of the differential signals according to the received configurations, and analyzing the differential signal transmissions into different signal modes corresponding to the different channel modes; transforming each signal mode and the impulse response of a corresponding channel mode to respectively generate a first value and a second value by utilizing Fast Fourier Transform Algorithm; multiplying the first value by the second value to generate a third value, and transforming the third value to a fourth value by utilizing an Inverse Fast Fourier Transform Algorithm; and summing all the fourth values corresponding to all of the channel modes to be the response values sum of the differential signals. A related system is also disclosed.

The invention is in the field of distributed Raman amplification for digital and analog transmission applications and other applications, e.g., instrumentation and imaging applications, including HFC-CATV applications. In particular, the invention uses a high power broadband source of amplified spontaneous emission (ASE) as the Raman pump source for improved system performance. The invention also includes methods for constructing such a high-power broadband Raman pump.

A transmission apparatus according to the present invention includes: an encoding section; a modulation section; a variable-SF spreading section that performs spreading with variable SF according to control information A from a control section; an IDFT section that performs IDFT on output from the spreading section; a GI inserting section; a parallel/serial conversion section that converts output from the GI inserting section into a serial data sequence; a digital/analog conversion section; and an RF section that transmits a signal from an antenna after converting the signal to a frequency band for analog signal transmission and controlling it to an appropriate transmission power. The control section is configured to generate control information A for determining the variable SF and input the information A to the variable-SF spreading section and the RF section. In control information A, SF is varied depending on transmission power required.

An adjustable-delay filter performs wave shaping to emulate pre-emphasis or de-emphasis of transmission-line signals. The adjustable-delay filter uses analog components and does not need a clock. The receiver does not have to recover a bit-clock from the data stream, eliminating a clock recovery circuit. An input buffer receives the input signal and drives current to a summer and to an adjustable delay. The adjustable delay inverts and delays the current and drives a delayed, inverted current to the summer. The summer combines the delayed, inverted current and the current from the input buffer to generate an output signal. The delay time of the adjustable delay can be programmed by a user and is less than the bit period. After a signal transition, the output signal initially spikes higher, then falls back to a nominal level after the delay time has expired. The initial signal spike emulates de-emphasis or pre-emphasis.

Disclosed are a wireless channel realtime simulator and a simulation method oriented to deep space communication. The wireless channel realtime simulator and the simulation method are supportive of realtime duplex communication channel simulation of an uplink and a downlink. The wireless channel realtime simulator comprises a main control unit, a baseband signal channel simulation unit, a frequency changer unit and an attenuator unit, the main control unit is in data and order transmission with the baseband signal channel simulation unit, the frequency changer unit and the attenuator unit through a CPCI bus, and the baseband channel simulation unit, the frequency changer unit and the attenuator unit are in analog signal transmission through an SMA interface. By combining the wireless channel realtime simulator with the simulator method, transmission conditions of wireless signals under a deep space background can be effectively simulated in real time, and debugging, testing and performance evaluating of deep space communication equipment are realized in a ground laboratory.

A communications system comprising a plurality of terminals each having a neural network therein which has parameter values enabling the network to emulate a transmission processing stage in a transmission mode, and a transmission station for sending new parameter values to the terminals to change the operation of the neural networks to emulate a new transmission mode.

A method and system are provided for adaptively modeling and simulating high speed response of a transmission line. A simulation unit maintains a plurality of curve approximation options for modeling the transmission line. The suitability of a predefined primary one of the curve approximation options for modeling is determined based on frequency-domain modal scattering parameters obtained according to frequency-dependent data characterizing the transmission line. One of the options is selectively executed in response to the determination, in order to generate a macromodel of the transmission line. The primary option is executed upon determination of suitability, while a secondary one of the curve approximation options is alternatively executed upon determination of non-suitability. Transient simulation is then executed upon the resulting macromodel of the transmission line.

A system includes the mobile terminals, the communication base stations, the monitoring center and global position satellite. The vehicle carried nevigation terminal in the mobile terminal is composed of the GPS antenna, the OEM receiving border, CPU, the storage for digital map, the interface for IC card, the display memry, the sequential control circuit, the and the IDEN handset interface circuit etc. The vehicle carried transmission terminal consists of the camera head, the image collection chip as well as the said sequential control circuit, CPU, the storage for images. The vehicle carried analog transmission terminal includes the GPS antenna, the OEM receiving border, CPU, the data storage, modem and the broadcasting station interface circuit.

The invention discloses a method and a system for measuring network service quality. The method comprises: a measurement server conforms a measurement policy according to a measurement demand and network data and node number, which includes: nodes involved in the measurement and measurement works to be finished; the measurement server separately transmits the measurement policy to each node involved in the measurement as a dispatching order form; the measurement content includes service quality measurement of a certain business; the nodes involved in the measurement finishes the measurement works based on the dispatching order, which comprises simulating the measurement data packs of an application layer protocol used by transmission between nodes, counting the service quality parameters between the nodes and reporting the parameters to the measurement server. The method for measuring network service quality can simulate the different processing modes of different businesses, and obtain an exact service quality situation of different businesses.

A radio communication device comprises a processor configured to generate a transmission signal on the basis of data to be transmitted. The processor generates the transmission signal by a transmission scheme selected from a digital transmission scheme and an analog transmission scheme. The digital transmission scheme is a transmission scheme by which a bit stream obtained through binary encoding of the data to be transmitted is converted into the transmission signal. The analog transmission scheme is a transmission scheme by which the data to be transmitted directly is converted into the transmission signal without performing binary encoding of the data to be transmitted.