Adaptive Usage of Main Resources in MIMO-Cognitive Radio Networks

Shalva Kvirkvelia (PHD student) Prof. Teimuraz Kortua Prof. Jemal Beridze

GEORGIA

Tbilisi

Georgian Technical UniversityDepartment of Telecommunication

MIMO system

Linear Capacity Growth

Theoretical The MIMO Systems capacity grows linearly with the number of antennas. 2x2 MIMO doubles the capacity and 4x4 MIMO quadruples capacity.

The linearity occurs only when we have ideal channel conditions, there is no interference among subcarriers, channels are orthogonal and there is no correlation between the channels.

Cognitive radio

The four major functions of a cognitive network are

• Spectrum sensing: detection of unused frequency ranges

• Spectrum management: selection of the unused frequency range that best fulfills the requirements

• Spectrum mobility: possibility to switch frequencies without data loss and additional delay (e.g. by detecting a band with less interference)

• Spectrum sharing: intelligent, multiple access to a spectrum within a network

Cognitive-MIMO

• cognitive radio network• data on the MIMO channel• resources-adaptive algorithms• optimal transmission circuit

Multipath propagation

Inter symbol interference

Cyclic prefix

Rate loss

Resource loss

Multipath estimating tool

Example

IEEE 802.16-2004 OFDM PHY link, Including Space-Time Block Coding

Results

Adaptive MIMO System with OSTBC

Results

Downlink Transport Channel (DL-SCH) Processing

Results

LTE Transmit Diversity Example

Results

Thank you Questions?