Belar FMHD-1, Руководство оператора

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FMHD-1 Operator’s Manual
BELAR ELECTRONICS LABORATORY, INC. Page 37
PSD
In the HD Radio context, this refers to “Program Service Data”. This is the information transmitted as
part of the data stream for the benefit of the audience. For musical formats, this information typically
would include information such as the title, artist, album, and genre of a selection, and possibly include
commentary.
Peak
The maximum instantaneous value of a waveform, whether modulation, voltage, or current. In the
FMHD-1, signal peaks are the maximum absolute values of a waveform.
PC
A personal computer.
Pilot
The 19-kHz sine-wave component of the broadcast composite FM Stereo signal used to synchronize
demodulation of the L–R sub-channel at FM receivers. On the
FMHD-1 , the pilot signal is obtained by
band-pass filtering the composite signal after its recovery by the FM demodulator.
Pre-emphasis
The emphasizing of higher audio frequencies of monaural and stereo and audio signals at the transmitter
employed to improve the signal-to-noise ratio of the signals recovered at the receiver. This is a
signal-differentiating process with a defining time-constant that sets the break frequency for the rising
filter response. (See “De-Emphasis” above.)
RF
This refers to “radio frequency”, either as an adjective, or as a noun.
RMS
This is the root-mean-square. It is the power-equivalent of a voltage or current signal.
Separate-Line Facilities
In FM hybrid IBOC transmitter facilities, this refers to the situation where two transmitters independently
feed either a dual-feed antenna or two separate antennas via two transmission lines. (This situation
requires two samples be applied to the FMHD-1, and that the system losses are carefully accounted for
when the input levels to the monitor are set.)
SIS
This is the Station Information Service. It is a system that carries textual information about the station
broadcasting the data. It is carried as part of the digital data stream of the IBOC system. The information
may include station call-sign, geographical coordinates of the transmitting antenna, country, and long
station identifiers.
SNR, S/N
Signal-to-noise ratio: the power ratio of a signal to the noise present in the same channel. SNR is usually
expressed in decibels.
Stereo Sub-Carrier
The second harmonic of the 19-kHz pilot signal which is modulated by the L–R difference audio signal to
form the stereo sub-channel. It is also the 38-kHz signal regenerated from the pilot signal, which is used
to demodulate the stereo sub-channel at the receiver.