It's length is determined by the modulation, the number of CDMA channels used, and the forward error correction Code Rate.
Thus, we inferred velocities in the lower crust and uppermost mantle by trial-and-error fitting of observed distant travel times using the forward modeling.
However, in any transmission system the forward error correction coding is used in conjunction with interleaving.
It would be interesting to show how the global performance, when using powerful forward error correction (FEC) such as LDPC codes in the system, would be affected by the channel estimation strategies, and how it does so in the proposed transmission schemes.
Packet error probability approximation when turbo codes are applied was performed in [2], where the expressions for error probability were derived for AF, DF and hybrid AF/DF protocols, using strong forward error correction codes over Rayleigh fading.
A CP-OFDM system can take this into account by discarding the affected sub-carriers if the channel is known at the transmitter or by using forward error correction (FEC) codes if it is not [8, 11].
Wyner defined that physical layer security is achieved without key distribution using forward error correction (FEC) when it corresponds to the considerations of reliability and security.
In some other related studies, WZ coding is used as forward error correction to protect the video transmission.
Even after transmission over 20 km SMF and splitting ratio of 32, acceptable transmission performance and widely separated constellation diagrams for the 16-QAM signals are achieved, with bit error rate (BER) of 10−6 for DS signals and 10−3 for the US signals which can be reduced down to 10−6 by using forward error correction (FEC).
There are several methods for the sender-based reconstruction schemes including packet retransmission [6], interleaving [7], and sending error correction bits in voice packets using forward error correction (FEC) technique [8].
