  This paper presents a novel wireless image transmission paradigm that can
exploit feedback from the receiver, called DeepJSCC-ViT-f. We consider a block
feedback channel model, where the transmitter receives noiseless/noisy channel
output feedback after each block. The proposed scheme employs a single encoder
to facilitate transmission over multiple blocks, refining the receiver's
estimation at each block. Specifically, the unified encoder of DeepJSCC-ViT-f
can leverage the semantic information from the source image, and acquire
channel state information and the decoder's current belief about the source
image from the feedback signal to generate coded symbols at each block.
Numerical experiments show that our DeepJSCC-ViT-f scheme achieves
state-of-the-art transmission performance with robustness to noise in the
feedback link. Additionally, DeepJSCC-ViT-f can adapt to the channel condition
directly through feedback without the need for separate channel estimation. We
further extend the scope of the DeepJSCC-ViT-f approach to include the
broadcast channel, which enables the transmitter to generate broadcast codes in
accordance with signal semantics and channel feedback from individual
receivers.
