Application Scenario

• Each user is equipped with Nt transmit antennas• WAR (Wireless Access Router) is equipped with Nr receive antennas

System’s Architecture

( )s t1N

( ( ), ( ), ( )) qt s tr t( ( ), ( ), ( )) qs tt t

VBR media Encoder

Wireless

Connection

( )t

VBR media

Decoder

2N( ( ), ( ), ( )) t s t q t

V(t)BL

Loss-affected MAC queue

R

( )q t

Physical layer configuration

D.N.Tse, P.Viswanath, L.Zheng,’’ Diversity-Multiplexing Tradeoff in Multiple-Access Channels’’,IEEE Tr.on Inform. Theory, vol.50, no.9, pp.1859, 2004.

Diversity-vs-Multiplexing-vs-SDMA tradeoff

• The best diversity-multiplexing curve attainable by the MIMO MAC channel

,

*,

( ), 0 / 1

( ) ( ), / 1 min ; /

0, min ; /

t r

t r

N N s s r

s UN N s r s t r

s t r

N U

d U N U N N U

N N U

Piecewise linear curve

( )( )

i daveFER

i-th average Frame Error Rate at the MAC layer

MIMO MAC Packet loss

2 22

max

min max

max

1 1 1 1

2 1

ii RL i ii

B R RR

tt

L t tt

( ) ( )2 0

*0 0 2 2 2

( ) min ; log ( ) ( / )8

log log det log det ( / sec. / )

i is HR t c c s ave

s t R T

TWlt N r M z lt byte slot

N Cov Cov bit Hz

MIMO MAC service rate

Multiple User Systems

Dynamic resource allocations

BackboneAccess PointClient Device

Jointoptimization

MISO System MIMO System

Optimization problem

a1 S1

a2 S2

aM SM

...

(s t)Wirelesschannel...

7

Weights

MISO Systems - Multiplexer

Queue weights depending on the Class of Service of the different input

streams

8

The radiated energies and the system state partitioning for the jointly optimal scheduler