Yingbo Hua

1
Networking of MIMO Nodes Yingbo Hua University
of California, Riverside MURI Project Review at
UCSD July 28, 2005
2
Overview - 1/4

• Networking of MIMO Nodes
• Design of MIMO Relay Nodes
• Design of Networking Protocols for MIMO Nodes

3
Overview - 2/4

• Design of MIMO Relay Nodes
• 1.1 Regenerative MIMO relay nodes
  (conventional)
• Advantages uniform functional modules,
  suitable for
• large scale networking, robustness
• Disadvantages time consumed for coding,
  decoding,
• and handshaking for each packet at each node
• 1.2 Non-regenerative (NR) MIMO relay nodes
  (new)
• Advantages fast, virtually analog, no
  handshaking
• required for each packet (using freq.
  division)
• Disadvantages NR alone is not suitable for
  many-hops
• relaying (noise accumulates)

4
Overview - 3/4

• 2. Design of Networking Protocols for MIMO
• Nodes
• 2.1 Route discovery algorithms
• 2.2 Data forwarding algorithms
• 2.2.1 Data forwarding without a given route
  (much attention)
• 2.2.2 Data forwarding with a given route
  (little attention)
• A given route often exists between two nodes.
• Network topology can remain relatively
  stationary
• with respect to a stream of packets
  (w.r.t.s.p.).
• But the link qualities between nodes can be
  random
• (w.r.t.s.p.) due to motions of the network or
  changes in
• the environment.

5
Overview - 4/4

• We will show
• Optimal design of non-regenerative (NR) MIMO
  relays
• A route-guided multicast (RGMC) data forwarding
  policy

6
A. Optimal Design of NR MIMO Relay 1/6
Tang and Hua, IEEE SPAWC05 Tang and Hua,
IEEE T Wireless Com, submitted, July 2005
We will focus on the case
7
A. Optimal Design of NR MIMO Relay 2/6
Capacity of the relay channel between source and
sink without the direct link
SNR at relay
relay-sink matrix
source-relay matrix
relay matrix
8
A. Optimal Design of NR MIMO Relay 3/6
An optimization problem
Maximize the relay link capacity
subject to the power constraint at the relay
9
A. Optimal Design of NR MIMO Relay 4/6
The optimal solution is
where
10
A. Optimal Design of NR MIMO Relay 5/6
is monotonically increasing function and has a
unique root.
11
A. Optimal Design of NR MIMO Relay 6/6
12
B. A Route-Guided Multicast Data Forwarding
Policy 1/9
Ye and Hua, MILCOM 2005 Ye and Hua, IEEE T
Wireless Com, submitted, July 2005
Multicast
Unicast
13
B. A Route-Guided Multicast Data Forwarding
Policy 2/9
14
B. A Route-Guided Multicast Data Forwarding
Policy 3/9

• Assumptions
• Packet is received/decoded correctly iff the SINR
  
• exceeds a threshold
• The pdf of the received power for each packet
  follows

15
B. A Route-Guided Multicast Data Forwarding
Policy 4/9
A linear network
RGMC
RGUC1
RGUC2
16
B. A Route-Guided Multicast Data Forwarding
Policy 5/9
ETE delay over a linear network of 100 relays
17
B. A Route-Guided Multicast Data Forwarding
Policy 6/9
Progress efficiency over a linear network of 100
relays
18
B. A Route-Guided Multicast Data Forwarding
Policy 7/9
We adopted the parameters of the transceivers by
Motorola Chen, ODea, Galaway, ICC02, e.g.,
Amplifier efficiency 20
Receiver noise figure 11dB
Carrier wavelength 0.125m
Transmission antenna gain 1
19
B. A Route-Guided Multicast Data Forwarding
Policy 8/9
A random network

• Each node
• emits with 3
• prob.

• Each node has
• a Poisson traffic
• of average 0.16

• 225 nodes are
• uniformly
• randomly
• distributed.

• 100 realizations

20
B. A Route-Guided Multicast Data Forwarding
Policy 9/9

• RGMC/RGUC ratios of efficiency, delay and
  energy over a random network of 225 nodes.
• Average connectivity 6.

21
Conclusions and Accomplishments 1/2

• Non-regenerative MIMO relays are useful for fast
  relaying
• between MIMO nodes. We have discovered the
  optimal
• waveform shaping matrix that maximizes the
  capacity of
• the relay channel. Tang and Hua, SPAWC, 2005
• Route-guided data forwarding policies are
  important for
• large volume data transmissions over ad hoc
  networks. We
• have formulated and studied a route-guided
  multicast data
• forwarding policy. Ye and Hua, MILCOM, 2005
• A route of parallel relays with distributed
  space-time coding is
• an important concept. Our analysis shows that a
  route of
• parallel relays has a much longer lifetime than
  routes of serial
• relays while the increase of routing overhead is
  negligible.
• Ye and Hua, Asilomar, 2004

22
Conclusions and Accomplishments 2/2

• List of publications partially supported by MURI

• Z. YE and Y. HUA, Networking by parallel relays
  diversity, lifetime and routing overhead, The
  38th Annual Asilomar Conference on Signals,
  Systems and Computers, pp. 1302-1306, Pacific
  Grove, CA, Nov 7-10, 2004.
• Z. YE and Y. HUA, Stability of wireless relays
  in mobile ad hoc networks, IEEE ICASSP2005,
  Philadelphia, PA, March 2005.
• X. TANG and Y. HUA, Optimal waveform design for
  MIMO relays IEEE Workshop on Signal Processing
  Advances for Wireless Communications, New York,
  NY, June 2005.
• Z. YE, and Y. HUA, "On link layer policies of
  data forwarding over wireless relays", MILCOM,
  Atlantic City, NJ, Oct 2005.
• X. TANG and Y. HUA, "Optimal design of
  non-regenerative MIMO wireless relays", IEEE
  Transactions on Wireless Communications,
  submitted July 2005.
• Z. YE and Y. HUA, "A route-guided multicast data
  forwarding policy for wireless relays," IEEE
  Transactions on Wireless Communications,
  submitted July 2005.

23
Future Work

• Interleaving regenerative and non-regenerative
  MIMO relays
• should improve the network throughput. Further
  investigation
• will be done.
• Route-guided multicast data forwarding policy is
  particularly
• suitable for networks of MIMO nodes where
  processing power
• is not an issue. More realistic analysis and
  simulation will be
• done to further verify its feasibility and
  performance.
• Routes of parallel MIMO nodes will be
  investigated. This
• will achieve a new level of cross layer
  cooperation of MIMO
• nodes.
• Collaborations within MURI with Jim on overall
  directions
• JJ and Srikanth on networking protocols Mike
  and Lee on NR
• MIMO relays and Hamid on distributed coding for
  parallel relays.