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A Method of Improving MIMO-OFDM Performance Using Optimal Pilot Allocation

Project ID: 1745-AP
Available for licensing

Background

Multiple-input multiple-output (MIMO) systems, when used in conjunction with orthogonal frequency division multiplexing (OFDM) technology, are promising in terms of providing high data rate wireless communications with easy-to-implement hardware. In fact, MIMO-OFDM is the strongest candidate of choice for future high data rate wireless deployments. The end-to-end performance of MIMO-OFDM systems relies heavily on the acquisition of accurate channel state information at the receiver end (mobile unit). Inserting pilot symbols into the data streams is the adopted method of such an acquisition in conventional systems.

Invention Description

A systematic method of optimizing the pilot stream at the base station for space-time block-coded MIMO-OFDM wireless systems is proposed. Using a feedback link from the mobile station, the base station inserts pilot symbols within the frequency band such that a) the symbol error-rate of the system is minimized (link reliability is maximized), or b) the capacity of the link is maximized.

Benefits

Minimized system error rate
Orthogonality for ease of implementation in hardware
Receiver side optimization/signal processing, and hence reduced transmitter complexity
Scalability

Features

Extraction of frequency diversity gains afforded by non-uniform pilot structure
Power savings at base station
Low-complexity receiver structures
High data rate OFDM communications
Reliable communications via MIMO communications
Directly applicable to 3G networks such as the IEEE 802.16 (WiMAX) standard

Market Potential/Applications

Existing and future wireless multimedia-over-IP networks

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