Advanced Micro Devices Corporation

Harish Kutagulla

Chien-Meen Hwang

Terry Lynn Cole

Thomas Hanusch

Xu Zhou

Michael Barclay

Ping Hou

A method and apparatus for testing the functionality of a circuit design uses working system data that is recorded in real-time to stimulate and/or verify a software simulation of the circuit design that does not run in real-time. In a selected embodiment, a system for simulating and verifying a software model of a baseband module circuit design is described in connection with using real-time input and output data captured from a corresponding circuit in a reference platform. The captured real-time data may include digital baseband I/Q samples and/or extracted control data pertaining to the signal level, channel frequency, gain, output power, frequency offset, DC offset, or the like. The captured data may be regenerated for use as a stimulus for the software model of the circuit design and/or to verify the functionality of the design. Additional processing of the captured data can remove non-idealities that may be present in the reference platform, and can synchronize the regeneration of the captured data with the timing requirements of the non-real-time software model.

Data generation and collection from a real-time system for non-real-time software simulation

An OFDM receiver is configured for suppressing pilot energy, and DC energy, from received I and Q components prior to estimating amplitude and phase imbalances of the received I and Q components. Hence, amplitude and phase imbalances can be estimated accurately despite channel fading and frequency variations between the transmitter and receiver.

Time domain estimation of IQ imbalance in a wireless OFDM direct conversion receiver

A channel estimator is configured for determining a gain adjustment for a received wireless signal having a prescribed plurality of tones. The channel estimator is configured for generating, for each of the tones, a corresponding pseudo power value representing a detected power level for the corresponding tone. An accumulated pseudo power value is obtained based on accumulating the respective pseudo power values of the prescribed plurality of tones. Each of the pseudo power values is selectively adjusted by an adjustment factor based on a determined difference between the accumulated pseudo power value relative to an expected accumulated power level relative to a prescribed dynamic range. The pseudo power values are then output for decoding of data modulated at the respective tones.

OFDM receiver having adaptive channel estimator for correcting channel fading based on accumulated pseudo power values

An OFDM receiver has a DC offset estimator configured for determining a DC offset, in I and Q components of a received OFDM signal having been output by an analog front end, based on filtering prescribed subcarrier components from a preamble segment of the I and Q components. The OFDM receiver removes the determined DC offset from the I and Q components, resulting in respective corrected I and Q components having minimal DC offset.

DC offset cancellation in a direct conversion receiver configured for receiving an OFDM signal

An OFDM transceiver has a transmitter, a receiver, and a loopback switch. The loopback switch configured is for selectively establishing a physical connection between an output terminal of the transmitter and an input terminal of the receiver. The transmitter is configured for outputting to the output terminal an OFDM signal generated based on a local oscillator signal. The receiver is configured for demodulating the OFDM signal, received via the physical connection, using the local oscillator signal and determining amplitude and phase imbalance parameters based on performing frequency-domain estimation of amplitude and phase imbalances. Hence, the receiver is configured for performing imbalance compensation on a received wireless OFDM signal based on the determined amplitude and phase imbalance parameters. Hence, amplitude and phase imbalances can be estimated accurately despite channel fading and frequency variations encountered between the transmitter of the wireless OFDM signal and the receiver.

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Austin, TX, United States of America

Harish Kutagulla