  It has previously been shown that ensembles of terminated protograph-based
low-density parity-check (LDPC) convolutional codes have a typical minimum
distance that grows linearly with block length and that they are capable of
achieving capacity approaching iterative decoding thresholds on the binary
erasure channel (BEC). In this paper, we review a recent result that the
dramatic threshold improvement obtained by terminating LDPC convolutional codes
extends to the additive white Gaussian noise (AWGN) channel. Also, using a
(3,6)-regular protograph-based LDPC convolutional code ensemble as an example,
we perform an asymptotic trapping set analysis of terminated LDPC convolutional
code ensembles. In addition to capacity approaching iterative decoding
thresholds and linearly growing minimum distance, we find that the smallest
non-empty trapping set of a terminated ensemble grows linearly with block
length.
