Open AccessSpace alignment for cognitive transmission with multiple primary users
Author(s) -
Bai Xiaojuan
Publication year - 2013
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2013.2524
Subject(s) - transmission (telecommunications) , computer science , primary (astronomy) , space (punctuation) , cognitive radio , cognition , electronic engineering , telecommunications , engineering , psychology , physics , wireless , neuroscience , astronomy , operating system
A space‐alignment (SA) scheme with K primary users in different cells working in the same frequency band based on K ‐symbol extension for cognitive transmission in a multiple‐input multiple‐output system is proposed. The main idea is that the secondary transmitter sends a supersymbol over the K timeslot; meanwhile, the secondary transmitter aligns its transmit directions by precoding to the k th primary channel eigenmodes unused at the k th timeslot, and at the same time adapts its transmit power to satisfy the interference‐power constraints at the other K − 1 primary receivers. The simulation results show that the proposed scheme achieves a higher performance compared with both the SA scheme with the single primary user and the scheme of the direct singular value decomposition of the secondary channel with interference‐power constraint.