Multiple Sensor Communications MIMO

1
Multiple Sensor Communications MIMO

• MESA Meeting

2
Our proposal

• Provide a low cost system with the necessary
  throughput
• Rely on existing standards
• Increase the system capacity with limited system
  impact
• Specialise an existing system to fulfil the MESA
  like system requirements
• MESA wireless system should cope with many
  transmissions scenarios
• Large-short coverage
• Indoor and out door
• We propose to adapt the 802.16 standard
• Increase rate with
• Limit the system impact at the access point

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MESA transmission context

• Provide high data rate transmission
• Many propagation scenarios
• Indoor
• Indoor to outdoor
• Outdoor
• Privilege the uplink
• Changes form the mass market considerations
• Coverage
• Form 100 m to few Km
• Central access point

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Different MIMO contexts

• Diversity coding point to point multiplexing

• Pros
• Full diversity codes exist (for codes)
• Rate increase
• No synchronisation issues
• Cons
• No benefit when no diversity (few scatters)
• Large existing standard modifications
• Where to put the antennas

• Multi-user transmissions (multi-point to point)

• Pros
• Capacity increase
• Terminals can be standard (ex low cost 802.16)
• Complexity at the access point
• Works even with no scatters (SDMA like)
• Cons
• System synchronisation between the transmitters
• Exists in TDMA/TDD systems

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Operational contexts Spatial diversity

• The technique should be adapted to the
  environment
• No scatters
• SDMA well suited
• Multiplexing (multi-point to point)
• - Multiplexing (point to point)
• - Diversity coding
• Channel with few scatters
• Multiplexing (multi-point to point)
• ? Diversity coding
• ? Multiplexing (point to point)
• - SDMA
• Channel with many scatters
• Multiplexing (multi-point to point)
• Diversity coding
• Multiplexing (point to point)
• - SDMA

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Sub optimal MMSE Rayleigh Channel

• Normalizing the transmitting power (P constant ?
  nb Tx)
• For a given power the system capacity is
  increased. Identical performance are achieved
  compared to the SISO system with a sub-optimal
  low cost receiver
• Further improvements in range/robustness/coverage
  are achievable with a little more complexity in
  the receiver

P
P/3
P/3
P/3
P/4
P/4
P/4
P/4
Eb/No for one user
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Conclusions

• The simultaneous multiple user transmission
  technique seem the better adapted to increase the
  capacity of existing standards (802.16)
• Provides enhancements in all transmission
  scenarios
• MESA mainly outdoor or indoor to outdoor
• Provides large systems improvements with minor
  changes to existing standards
• The terminals need a minor layer 1 and 2
  modification
• Privileges the uplink
• The complexity is deported to the access point
• Low cost terminals allow larger access to the
  system