  This work proposes adaptive buffer-aided distributed space-time coding
schemes and algorithms with feedback for wireless networks equipped with
buffer-aided relays. The proposed schemes employ a maximum likelihood receiver
at the destination and adjustable codes subject to a power constraint with an
amplify-and-forward cooperative strategy at the relays. Each relay is equipped
with a buffer and is capable of storing blocks of received symbols and
forwarding the data to the destination if selected. Different antenna
configurations and wireless channels, such as static block fading channels, are
considered. The effects of using buffer-aided relays to improve the bit error
rate (BER) performance are also studied. Adjustable relay selection and
optimization algorithms that exploit the extra degrees of freedom of relays
equipped with buffers are developed to improve the BER performance. We also
analyze the pairwise error probability and diversity of the system when using
the proposed schemes and algorithms in a cooperative network. Simulation
results show that the proposed schemes and algorithms obtain performance gains
over previously reported techniques.
