Codebook-Based Precoding for SDMA-OFDMA With Spectrum Sharing
This paper focuses on codebook-based precoding for Space-Division Multiple Access/Orthogonal Frequency-Division Multiple Access (SDMA-OFDMA) systems aiming to guarantee high throughput for their users as well as to mitigate interference to Fixed Satellite Service (FSS). A systematic design of SDMA codebook for subband-based OFDMA is proposed, which forms multiple orthogonal beams with common spatial null in the direction of a victim FSS Earth Station (ES). The design enables both transmitter and receiver to independently construct identical codebook by sharing only on the direction angle of an FSS ES, which takes fewer overhead bits than Gram-Schmidt process, a general method satisfying the authors' design criterion.
Provided by: ETRI Journal Topic: Networking Date Added: Dec 2011 Format: PDF