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A Data Replication Method for Reducing the Pilot Symbol Overhead in STBC MIMO-OFDM Wireless Communication Systems

Project ID: 1749-AP
Available for licensing

Background

Demand for high data rate and increased coverage for wireless communication networks have drawn significant attention towards utilizing multiple antennas at both the transmitter and receiver sides (MIMO techniques). The high scattering characteristics of urban communication mediums introduce more challenges into wireless network system designs. Space time block codes (STBC) together with orthogonal frequency division multiplexing (OFDM) are shown to be useful tools in adapting multiple antenna systems in high scattering environment. Alamouti space time block code, which is based on two transmit antennas and a single receiving antenna, due to its simplicity, is being widely encapsulated into the current wireless communications standards.

Inserting known pilot symbols into the data streams is one of the widely used techniques to understand the characteristics of the channel at the receiver and decode the transmitted signal. However, the pilot symbol insertion enforces excessive overhead to the communication systems, and it is desirable to reduce the number of pilots required to achieve a certain quality of transmission.

Invention Description

Our invention reduces the number of required known pilots in Alamouti STBC MIMO-OFDM wireless communications systems without adding any significant complexity.

Benefits

Keeps receivers simple
Number of known pilots reduced without addition of any significant complexity

Features

Number of known pilots required for a certain quality of service reduced by 25% compared to current pilot insertion methods
Fully software-based implementation
Backward compatible

Market Potential/Applications

Wireless communication systems based on Alamouti STBCs MIMO-OFDM (WiMAX, IEEE 802.11n) which are based on insertion of known pilot symbols into the data stream or any future standard using the mentioned methods.

UT Researcher

Robert W. Heath, Jr., Ph.D., Electrical and Computer Engineering, The University of Texas at Austin
Ali Y. Panah, Electrical and Computer Engineering, The University of Texas at Austin

OTC Contact Information

Jitendra Jain, Licensing Specialist
jjain@otc.utexas.edu
512-471-9055