Indeed, the QEF (quasi-error free) condition of the proposed DVB-T2 configuration is achieved when BER is equal to 10 4 with a LDPC decoding, which corresponds to a BER of approximately 10 7 after a BCH decoding [4].
thus is derived from subjective tests for transmission error-free conditions as follows:.
Erroneously decoded bits distort the soft input information, that is, the LLRs are calculated from erroneous data, which could result in failure to decode even though the assigned channel rate would prove sufficient when the soft input information were derived under error-free conditions.
The compressed bitstream is then divided in N k pieces, each one of (k−16) bits; a two-byte cyclic redundancy check (CRC) codeword, used to test for the error-free condition, is appended at the end of each piece (see Fig. 1).
One of the main advantages of using the ACM techniques is the ability to achieve quasi-error-free channel conditions for each individual user, by providing them with the most suitable ModCod value according to the measured SNIR, so that the spectral efficiency is as high as possible in all the cases.
Such techniques reduce the available link bandwidth (transmission rate), if necessary, to achieve quasi-error-free channel conditions for each individual user to provide them with the most suitable Modulation and Code (ModCod) value according to the measured signal-to-noise-plus-interference-ratio (SNIR) value reported by the return channel.
Despite the considerable variations in channel conditions and nonnegligible Doppler, successful error free detection was achieved throughout the entire transmission period.
l is selected to guarantee the broadcast packets error free in the channels where | h | > ln m m - l and s satisfies the condition m -l ≤ s ≤ m.
uninterrupted and error free; 13.6.2.
The transmission channels are error free.
(A.4) The transmission channels are error free. .
