Photonic-enabled broadband radio frequency techniques - arbitrary waveform generation, ranging and wireless communication
Abstract
Wideband wireless systems have gained great interest from academia and industry due to the potentials in high data rate communication and high resolution radar applications. Photonic syntheses of wideband waveforms, especially those based on frequency-to-time mapping (FTM), have stood out from other approaches because of their ability to achieve enormous RF bandwidth. However, some of them perform poorly in repeatability while others suffer from issues like limited time aperture and time-bandwidth product, etc. These limitations greatly restrict the application of photonic generated waveforms in radar and communication applications. In this work, a novel photonic method of generating wideband radio frequency (RF) signals that combines FTM-based RF arbitrary waveform generation and waveform switching under pseudorandom sequence modulation is proposed and experimentally demonstrated. Using this method we generate repeatable RF waveforms with tens of gigahertz bandwidth, arbitrary time aperture and time-bandwidth product, and high average power in both ultra wideband (UWB) and W-band. Utilizing the generated waveforms, RF ranging experiments with high-resolution (up to 3.9 mm) and long unambiguous detection range (up to 9 meters) are conducted in both UWB and W-band. Furthermore, based on our photonic RF-AWG, a communication system is assembled to realize fast channel sounding, pre-compensated signal generation and real-time wireless data transmission in the UWB. Error-free data transmissions covering 2 – 18 GHz at 250 Mbits/sec in OOK and BPSK modulation formats are realized in both highly dispersive line-of-sight (LOS) and dense-multipath non-line-of-sight (NLOS) environments. Our experiments are the first to our knowledge to directly compare the communication performance of phase compensation and time reversal schemes in a strong multipath channel; our results demonstrate that the phase compensation scheme provides significantly enhanced suppression of intersymbol interference.
Degree
Ph.D.
Advisors
Weiner, Purdue University.
Subject Area
Electrical engineering|Optics
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