GB/T 26252-2010Frequency planning criteria for digital terrestrial television broadcasting in the VHF/UHF bands (English PDF)

3.1

Terms and DefinitionFor the purposes of this standard, the following term and definition applies.3.1.1

Wanted signal

The RF signal with information to be received.3.1.2

Unwanted signal

Other RF signal irrelevant to the information to be received.3.1.3

RF protection ratio

The minimum power ratio of wanted signal to unwanted signal at the normal receiving conditions, generally measured at the receiver inlet and represented by dB.

3.1.4 Time probability

The percentage of time when the signal field strength reaches or exceeds a certain given value to the observation time, at any measuring position if the signal varies with the time.

3.1.5 Location probability

The percentage of the location where a given value is reached or exceeded to the small measured area (typical value is 100m×100m) when the signal field strength varies with the locations to be measured.3.1.6

Minimum equivalent field strength

The minimum field strength to ensure the receiver on the digital terrestrial television can receive the signal normally without other signal interference.

Note: The power spectrum density of broadband signal is varied throughout the signal bandwidth, so the "equivalent field strength" is usually adopted instead of "field strength". The equivalent field strength is the irradiation field strength of the non-modulating signal, having the equal power with the broadband signal.

3.1.7 Minimum median equivalent field strength

The minimum median field strength to ensure the receiver on the digital terrestrial television can receive the signal normally considering that the statistical factors of wanted signal field strength will vary with the time and location.3.2 Abbreviations

For the purpose of this standard, the following abbreviations apply.

BER Bit Error Rate

C/N Carrier-noise ratio

MFN Multiple Frequency Network

PR Protection Ratio

QAM Quadrature Amplitude Modulation

SFN Single Frequency Network

TS Transport Stream