  We propose an iterative decoding method, which we call turbo-CS, for the
reception of concatenated source-channel encoded sparse signals transmitted
over an AWGN channel. The turbo-CS encoder applies 1-bit compressed sensing as
a source encoder concatenated serially with a convolutional channel encoder. At
the turbo-CS decoder, an iterative joint source-channel decoding method is
proposed for signal reconstruction. We analyze, for the first time, the
convergence of turbo-CS decoder by determining an EXIT chart of the constituent
decoders. We modify the soft-outputs of the decoder to improve the signal
reconstruction performance of turbo-CS decoder. For a fixed signal
reconstruction performance RSNR of 10 dB, we achieve more than 5 dB of
improvement in the channel SNR after 6 iterations of the turbo-CS.
Alternatively, for a fixed SNR of -1 dB, we achieve a 10 dB improvement in
RSNR.
