Optimal ARQ Protocol For Multihop MIMO Relay Networks Yao Xie, Deniz Gunduz, Andrea Goldsmith

1
Optimal ARQ Protocol For Multihop MIMO Relay
Networks Yao Xie, Deniz Gunduz, Andrea Goldsmith
Found optimal ARQ protocol in multihop
MIMO relay networks. Characterized DMDT surfaces
provide insights for practical optimal ARQ
protocols design.

• MAIN RESULTS
• 3D DMDT Surfaces for Various ARQ protocols
  ((4,1,3) system)
• ASSUMPTIONS AND LIMITATIONS
• Long-term/short-term static channel

diversity
What is the rate-reliability-delay tradeoff in
multihop MIMO relay networks?
Fractional variable
L 1
Block variable

• There are
• Diversity-multiplexing tradeoff (DMT) analysis
  for relay channel
• Diversity-multiplexing-delay tradeoff (DMDT) for
  point-to-point MIMO with ARQ

multiplexing
Block Variable ARQ
Fractional Variable ARQ
L 10
(2,2,2) system
Long-term

• We characterize the diversity-multiplexing-delay
  tradeoff (DMDT) surface for various ARQ protocols
  
• Theorem the fractional variable ARQ protocol
  achieves optimal DMDT
• Relay should talk ASAP

ARQ 1
ARQ 2
diversity
How it works ARQ protocols in the MIMO relay
networks
H2
H1
Short-term
Optimal Operational Point
rate

• Optimal ARQ protocol for general relay networks
• Effects of power control
• Joint source-channel coding in MIMO relay
  networks

ARQ protocol provides one more dimension of
tradeoff in MIMO relay networks.