Orthogonal frequency division multiplexing (OFDM) waveform is promising to converge communications and sensing functionalities for future wireless applications. This paper presents a novel method to improve the OFDM-b...Orthogonal frequency division multiplexing (OFDM) waveform is promising to converge communications and sensing functionalities for future wireless applications. This paper presents a novel method to improve the OFDM-based sensing accuracy by estimating the delay/Doppler leakages in the channel matrix, which is constructed by the received and the transmitted OFDM symbols. Both simulation and proof-of-concept experiment validate the proposed method for sensing improvement.The experiment uses a heterodyne W-band system at 97 GHz to transmit and receive an OFDM waveform of bandwidth 3.9 GHz.We achieve an improvement in sensing accuracy by an order of magnitude which is significant for OFDM-based converged systems.展开更多
The acousto-optic modulator(AOM)plays an important role in heterodyne interferometric sensing,and it is always regarded as an ideal optical frequency shifter.In this paper,we compare the effects of its residual zero-o...The acousto-optic modulator(AOM)plays an important role in heterodyne interferometric sensing,and it is always regarded as an ideal optical frequency shifter.In this paper,we compare the effects of its residual zero-order diffraction in different AOM configurations.The theory shows that using double AOMs can effectively solve the same frequency crosstalk problem caused by zero-order perturbation without worsening the noise floor.The interferometer employs a photonics-assisted mmWave composed of two comb lines from an electro-optical frequency comb as the optical source,which results in the laser frequency noise cancellation in the difference.Experimentally,a dither with a peak-to-peak value of 0.15 ps in the single AOM configuration can be effectively suppressed to below the noise floor through double AOMs,which shows the potential to achieve high sensing accuracy.展开更多
Chinese technology company iFLYTEK Co.Ltd.launched an intelligent speech recognition system designed for humanoid robots this June.While traditional robotic performance suffers in noisy environments,this AI solution a...Chinese technology company iFLYTEK Co.Ltd.launched an intelligent speech recognition system designed for humanoid robots this June.While traditional robotic performance suffers in noisy environments,this AI solution achieves 92-percent environmental sensing accuracy-overcoming a key industry challenge.It enhances humanoid computers’ability to manage complex logistics and warehouse tasks.展开更多
基金the National Key Research and Development Program of China(2018YFB1801500)the Natural National Science Foundation of China(62101483)+1 种基金the Natural Science Foundation of Zhejiang Province(LQ21F010015)the Zhejiang Lab(2020LC0AD01)。
文摘Orthogonal frequency division multiplexing (OFDM) waveform is promising to converge communications and sensing functionalities for future wireless applications. This paper presents a novel method to improve the OFDM-based sensing accuracy by estimating the delay/Doppler leakages in the channel matrix, which is constructed by the received and the transmitted OFDM symbols. Both simulation and proof-of-concept experiment validate the proposed method for sensing improvement.The experiment uses a heterodyne W-band system at 97 GHz to transmit and receive an OFDM waveform of bandwidth 3.9 GHz.We achieve an improvement in sensing accuracy by an order of magnitude which is significant for OFDM-based converged systems.
基金supported by the National Natural Science Foundation of China(Nos.62071055 and 62135014)the BUPT Excellent Ph.D.Students Foundation(No.CX2022212)。
文摘The acousto-optic modulator(AOM)plays an important role in heterodyne interferometric sensing,and it is always regarded as an ideal optical frequency shifter.In this paper,we compare the effects of its residual zero-order diffraction in different AOM configurations.The theory shows that using double AOMs can effectively solve the same frequency crosstalk problem caused by zero-order perturbation without worsening the noise floor.The interferometer employs a photonics-assisted mmWave composed of two comb lines from an electro-optical frequency comb as the optical source,which results in the laser frequency noise cancellation in the difference.Experimentally,a dither with a peak-to-peak value of 0.15 ps in the single AOM configuration can be effectively suppressed to below the noise floor through double AOMs,which shows the potential to achieve high sensing accuracy.
文摘Chinese technology company iFLYTEK Co.Ltd.launched an intelligent speech recognition system designed for humanoid robots this June.While traditional robotic performance suffers in noisy environments,this AI solution achieves 92-percent environmental sensing accuracy-overcoming a key industry challenge.It enhances humanoid computers’ability to manage complex logistics and warehouse tasks.
