H03M1/004

Method and apparatus for generating OFDM signals

A method in a transmitter circuit of generating a signal comprising a first sequence of OFDM symbols, which are to be transmitted within a frequency sub band of a second sequence of OFDM symbols is disclosed. A first cyclic prefix (CP) of the second sequence of OFDM symbols has a first duration, and a second CP of the second sequence of OFDM symbols has a second duration. In order to generate both the first and the second cyclic prefix with an integer number of equidistant samples, a first sampling rate is required. The method comprises generating the signal comprising the first sequence of OFDM symbols at a second sampling rate, lower than the first sampling rate, and adjusting a sampling phase during CPs.

Decision feedback equalizer
10397028 · 2019-08-27 · ·

A decision-feedback equalizer (DFE) samples an analog input signal against M references during the same symbol time to produce M speculative samples. Select logic in the DFE then decodes N bits resolved previously for previous symbol times to select one of the M speculative samples as the present resolved bit. The present resolved bit is then stored as the most recent previously resolved bit in preparation for the next symbol time. The select logic can be can be programmable to accommodate process, environmental, and systematic variations.

Reconfigurable Ethernet receiver and an analog front-end circuit thereof
10361710 · 2019-07-23 · ·

The present application relates to a reconfigurable analog front-end circuit and a reconfigurable Ethernet transceiver with a reconfigurable analog front-end circuit. The circuit is reconfigurable using the at least one signal-path switching element controlled by a mode signal to operationally establish a first or a second signal path. The first signal path comprises an optional first signal-conditioning section and a shared ADC. The second signal path comprises an optional second signal-conditioning section, an upstream ADC and the shared ADC. The signal paths are selectively switched in response to a mode signal.

RING OSCILLATOR TEMPERATURE SENSOR
20190199329 · 2019-06-27 · ·

A sensor circuit includes at least one ring oscillator having a supply port supplied by at least one current source and a reference frequency. A comparator compares a frequency output of the at least one ring oscillator with the reference frequency to yield a measurement, such as a temperature measurement.

SYSTEMS AND METHODS ARE PROVIDED FOR UTILIZING RANDOMIZED ARRAY OFFSETS IN PHASED ARRAYS
20190198993 · 2019-06-27 ·

Systems and methods are provided for utilizing randomized array offsets in phased arrays. A phased array based system may include a plurality of antenna elements arranged in two-dimensional array, and a plurality of transceiver circuits, with each transceiver circuit configured for handling transmission and reception of radio frequency (RF) signals via the plurality of antenna elements. One or more transceiver circuits in the system may be configured for applying one or more randomized adjustments to one or more particular signal processing related functions applied during the transmission and reception of RF signals. The randomized adjustments may include randomized offsets to conversions applied during processing of transmitted and/or received signals. The conversion may include one or both of digital-to-analog conversions and analog-to-digital conversions. The offsets may be randomized based on indexes identifying corresponding antenna elements.

APPARATUS AND METHOD FOR CONVERSION BETWEEN ANALOG AND DIGITAL DOMAINS WITH A TIME STAMP
20190190556 · 2019-06-20 ·

An apparatus and method are disclosed with some embodiments including an analog and time to digital converter (ATDC) including a receiver, the receiver for receiving an analog channel input for conversion to a digital data, the digital data having at least one bit, and a defined absolute reference time stamp, the defined absolute reference time stamp representing an absolute reference time associated with conversion of the analog channel input to the digital data and an analog-to-digital converter, the converter converting the analog channel input to the digital data.

RECONFIGURABLE ETHERNET RECEIVER AND AN ANALOG FRONT-END CIRCUIT THEREOF
20190181872 · 2019-06-13 ·

The present application relates to a reconfigurable analog front-end circuit and a reconfigurable Ethernet transceiver with a reconfigurable analog front-end circuit. The circuit is reconfigurable using the at least one signal-path switching element controlled by a mode signal to operationally establish a first or a second signal path. The first signal path comprises an optional first signal-conditioning section and a shared ADC. The second signal path comprises an optional second signal-conditioning section, an upstream ADC and the shared ADC. The signal paths are selectively switched in response to a mode signal.

High resolution analog to digital converter (ADC) with improved bandwidth
12021541 · 2024-06-25 · ·

A high resolution analog to digital converter (ADC) with improved bandwidth senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. In addition, quantization noise is subtracted from the digital output signal thereby extending the operational bandwidth of the ADC. In certain examples, the operational bandwidth of the ADC extends up to 100s of kHz (e.g., 200-300 kHz), or even higher.

Baseline wander compensator and method

A baseline wander and offset correction system having inputs configured to receive input signals to be transmitted. Also part of the system is a driver circuit configured to receive and amplify the input signals. The driver circuit is configured with one or more transistors having an optional back bias terminal. A replica circuit receives the input signals and responsive thereto, generates back bias signals which are provided to the back bias terminal of the one or more transistors to change the back bias in response to the input signals having consecutive one values or consecutive zero values. This reduces the size of the one or more AC coupling capacitors located between the driver circuit and a channel. An embodiment may store back bias values in a memory. The back bias values are processed by DAC to generate the back bias signals for offset correction.

Differential current sensing circuit
12021540 · 2024-06-25 · ·

A high resolution analog to digital converter (ADC) with improved bandwidth senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. In addition, quantization noise is subtracted from the digital output signal thereby extending the operational bandwidth of the ADC. In certain examples, the operational bandwidth of the ADC extends up to 100s of kHz (e.g., 200-300 kHz), or even higher.