Young Seog Song

Computationally efficient compensations for some smart antenna systems

Some smart antenna systems need calibration, which measures the transmitter/receiver circuit path gains for each antenna and compensate the differences. Compensation is usually done in baseband using complex number multiplications. We propose efficient compensations for some time division duplex (TDD) smart antenna systems that use the channel reciprocity for downlink beamforming, and show that the number of arithmetic operations can be significantly reduced.

Uplink SDMA Performance Comparison of Single and Multiple Antenna Mobiles

Space-division multiple-access (SDMA) has been extensively studied for its increasing the throughput of cellular systems. One transmission antenna uplink SDMA, called cooperative spatial multiplexing (CSM) has been adopted for uplink SDMA in IEEE 802.16d standard [2]. For multiple transmission antennas mobile stations, we propose codebook based uplink transmission and compares its performance with CSM. System level simulation (SLS) for the orthogonal frequency division multiple access (OFDMA) cellular system is done to compare two systems. The proposed scheme results in substantial gain over the CSM in throughput.