Open AccessCodebook‐Based Precoding for SDMA‐OFDMA with Spectrum Sharing
Author(s) -
Jo HanShin
Publication year - 2011
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.11.0111.0078
Subject(s) - codebook , precoding , orthogonal frequency division multiple access , computer science , telecommunications link , overhead (engineering) , interference (communication) , space division multiple access , electronic engineering , zero forcing precoding , transmitter , spectral efficiency , throughput , mimo , algorithm , computer network , orthogonal frequency division multiplexing , wireless , channel (broadcasting) , engineering , telecommunications , operating system
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 our design criterion. A system‐level throughput evaluation shows that the proposed precoding provides superior performance over existing spectrum sharing method, that is, subband deactivation. The spectrum sharing analysis shows that the proposed precoding, even with an estimation error of the direction angles of an FSS ES, causes lower interference than existing precoding, knockdown precoding.