23 dB for interference from analog TV and DTV, respectively. At locations where the S/N ratio is greater than 16 dB but less than 28 dB, D/U values for co-channel interference to DTV are as follows:
(i) For DTV-to-DTV interference, the minimum D/U ratios are computed from the following formula:
D/U = 15 + 10log10[1.0/(1.0−10−x/10)]
Where x = S/N-15.19 (minimum signal to noise ratio)
(ii) For analog-to-DTV interference, the minimum D/U ratios are found from the following Table (for values between measured values, linear interpolation can be used):
Signal-to-noise ratio (dB)
Desired-to-undesired ratio (dB)
16.00
21.00
16.35
19.94
17.35
17.69