Bandwidth Efficient Diversity Scheme Using STTC Concatenated With STBC: MIMO Systems

Multiple-input multiple-output (MIMO) systems are widely in use to improve quality, reliability of wireless transmission and increase the spectral efficiency. However in MIMO systems, multiple copies of data are received after experiencing various channel effects. The limitations on account of complexity due to number of antennas in case of conventional decoding techniques have been looked into. Accordingly we propose a modified sphere decoder (MSD-1) algorithm with lower complexity and give rise to system with high spectral efficiency. With the aim to increase signal diversity we apply rotated quadrature amplitude modulation (QAM) constellation in multi dimensional space. Finally, we propose a new architecture involving space time trellis code (STTC) concatenated with space time block code (STBC) using MSD-1 at the receiver for improving system performance. The system gains have been verified with channel state information (CSI) errors.

Authors:

• Sameru Sharma
• Sanjay Sharma
• Derick Engles

Keywords:

• Channel State Information
• Diversity
• Multi-Antenna
• Rotated Constellation
• Space Time Codes.

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