Device for checking the integrity of a digital transmission for an analog output of a system. The analog output may be checked for transient errors that can be attributed to a digital transmission path embedded somewhere within the vehicle system. A test signal is introduced into a digital transmission that can be reassembled from an analog path of the analog output, and, if not, allows the test device to pinpoint that errors are appearing due to the digital path, and not because of the analog output. In this way, debugging an installation of a system becomes easier; obtaining confidence in reliability of a mixed analog and digital system becomes less of a challenge and less time consuming.

A test instrument or host device can apply inverse transmitter and receiver functions to data transmitted or received by an electrical and optical transponder. The inverse transmitter and receiver functions are applied to counteract internal signal conversion processes of the transponder. Forward error correction and test pattern analysis may be performed on signals received from the transponder after the inverse receiver function is applied to the received signals.

A test generator that determines an amplification level of an amplifier within a DFE and a method for determining the amplification level are disclosed. The test generator includes a signal generator that generates a test pattern signal characterized by a repeating digital test pattern and an offset voltage and an input signal port adapted to receive a digital DFE output signal from the DFE, the digital DFE output signal depending on the amplification level. The test generator includes an output control port that communicates a digital command word specifying a gain to be used by the amplifier in the DFE and a threshold for determining if a signal in the DFE is a logical one or logical zero. A controller determines the amplification level by measuring a BER between the test pattern and the digital DFE output signal as a function of the threshold and the offset voltage.

Methods and systems for an optoelectronic built-in self-test (BIST) system for silicon photonics optical transceivers may include an optoelectronic transceiver having a transmit (Tx) path and a receive (Rx) path, where the Rx path includes a main Rx path and a BIST loopback path. The system may generate a pseudo-random bit sequence (PRBS) signal, generate an optical signal in the Tx path by applying the PRBS signal to a modulator, communicate the optical signal to the BIST loopback path and convert the optical signal to an electrical signal utilizing a photodetector, where the photodetector is a replica of a photodetector in the main Rx path, and assess the performance of the Tx and Rx paths by extracting a PRBS signal from the electrical signal. The transceiver may be on a single complementary-metal oxide semiconductor (CMOS) die, or on two CMOS die where a first comprises electronic devices and a second comprises optical devices.

The present invention relates to an input/output signal synchronization method by a radio frequency unit. The input/output signal synchronization method according to the present invention comprises the steps of: generating a transmitter (Tx) input signal by adding, to a baseband signal, a test signal located at a frequency out of an operation frequency range of the radio frequency unit; collecting the Tx input signal and a Tx output signal obtained by outputting the input signal through a Tx function block; and synchronizing the Tx input signal and the Tx output signals, based on a result obtained by the collecting.

A system and method employ an exclusive-OR gate having a first input configured to receive an RF carrier signal having an RF carrier, and a second input configured to receive a square wave signal having a square wave frequency, to output to a signal processing channel under test a binary phase shift keying (BPSK) signal comprising the RF carrier signal modulated by the square wave signal. A digital signal processor is configured to receive from the signal processing channel in-phase (I) and quadrature-phase (Q) data produced by the signal processing channel in response to the BPSK signal, and to process the I and Q data to determine an amplitude response and phase response of the signal processing channel as a function of frequency.

Disclosed is an optical receiver and an error correction method performed by the optical receiver, receiving, using a receiving antenna or a photodetector, a training signal in which an error occurs due to noise and distortion while being output from an optical transmitter and transmitted through a communication channel and identifying a hyperplane for classifying a probability that the received training signal is a training signal corresponding to a training signal output from the optical signal using a support vector machine (SVM) and learning a parameter of the identified hyperplane such that a classification error probability is minimized when the probability is extracted using the identified hyperplane, wherein the parameter of the identified hyperplane is used to correct an error occurring while a transmission signal output from the optical signal is received using the receiving antenna or the photodetector.

Methods and systems for an optoelectronic built-in self-test (BIST) system for silicon photonics optical transceivers are disclosed and may include, in an optoelectronic transceiver having a transmit (Tx) path and a receive (Rx) path, where the Rx path includes a main Rx path and a BIST loopback path: generating a pseudo-random bit sequence (PRBS) signal, generating an optical signal in the Tx path by applying the PRBS signal to a modulator, communicating the optical signal to the BIST loopback path and converting to an electrical signal utilizing a photodetector, the photodetector being a replica of a photodetector in the main Rx path, and assessing the performance of the Tx and Rx paths by extracting a PRBS signal from the electrical signal. The transceiver may be a single complementary-metal oxide semiconductor (CMOS) die or in two CMOS die, where a first comprises electronic devices and a second comprises optical devices.

A test instrument measures performance of a transponder without direct access to a line interface of the transponder. The test instrument learns parameters of internal signal conversion processes of the transponder and measures performance of the transponder based on the learned parameters.

A variable ISI transmission channel apparatus inserted in a high-speed transmission channel for the high-speed serial data communication simulates a live ISI environment to which the high-speed transmission channel in operation is exposed, in a situation such as a bit error test by means of continuously adjusting an amount of inter-symbol interference (ISI) in the high-speed transmission channel.

By allowing an undersurface of a transmission loss generating member (6) (16) (26) such as a dielectric, a magnetic body, and an electric conductor to face, and slide on, a top surface of a conductor strip (2) exposed on a top surface of a plate-shaped dielectric substrate (1), a facing area is continuously increased/decreased. A dielectric loss, a magnetic loss, or a resistance loss increased/decreased in the transmission loss generating member is reflected on a high-frequency signal on the conductor strip (2).