HD Radio standard can realize the smooth transition from analog to digital using "in-band on-channel (IBOC)" technology, which is the most advantageous choice for analog broadcasting digitized. In HD Radio Hybrid and Extended waveform type, the digital signal employs the same carrier with the analog signal, and is transmitted on both sides of the analog FM signal. Since the digital carrier adjacent analog signal, the core to implement IBOC is the interference problem of digital signal to analog signal at the beginning of broadcasting digitized. For the interference evaluation model, this paper apply noise masking ratio (NMR) and objective evaluation level (ODG) as a combined evaluation factor for digital-analog interference in IBOC broadcasting. This interference evaluation method which utilizes the comprehensive advantages of NMR and ODG, with more scientific than the SNR measurements, can be widely used as an evaluation index for audio interference.
In-Band On-Channel (IBOC) as an AM&FM digital broadcasting technology is used in HD Radio standard. In Hybrid of HD Radio, the spectra of analog FM signal and digital signal are combined in a fixed way, without taking full advantage of spectra. To solve this problem, this paper presents a Dynamic Spectrum Access (DSA) method, using the idle spectrum on time dimension. And the improved method brings in a Perceptual Evaluation of Audio Quality (PEAQ) module based on the ear perception as the evaluation criterion to measure audio quality. The simulation results show that on the basis of insuring audio quality, this method can save a lot of spectral bandwidth to improve the available spectrum resources.
In HD Radio (Hybrid Digital Radio), the spectra of analog FM and digital signal are combined in a fixed way. However, the bandwidth of FM varies dynamically, which result in the insufficient utilization of spectrum in HD Radio. This paper analyzes the effect of different parameters on dynamic spectrum access scheme in HD Radio. The scheme extends the digital spectrum after detecting the spare spectrum of analog signal. Moreover, the analog signal is maintained a stable quality grade by employing an evaluation measurePEAQ (Perceptual Evaluation of Audio Quality). Simulation results of four programs show that the saved bandwidth of the scheme will achieve average 15 kHz with 42.7 (ms) of frames and dynamic digital spectrum.
A method is proposed for the retrieval of phase-related quantities from magnitude-only measurements on microwave networks that are to be manufactured and tested in large quantities. A reducedorder model is developed using the prototype of such a system and then used to retrieve the phase of nonprototype devices under test.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.