%X This paper investigates block-level interference exploitation (IE) precoding for multi-user multiple-input single-output (MU-MISO) downlink systems. To overcome the need for symbol-level IE precoding to frequently update the precoding matrix, we propose to jointly optimize all the precoders or transmit signals within a transmission block. The resultant precoders only need to be updated once per block, and while not necessarily constant over all the symbol slots, we refer to the technique as block-level slot-variant IE precoding. Through a careful examination of the optimal structure and the explicit duality inherent in block-level power minimization (PM) and signal-to-interference-plus-noise ratio (SINR) balancing (SB) problems, we discover that the joint optimization can be decomposed into subproblems with smaller variable sizes. As a step further, we propose block-level slot-invariant IE precoding by adding a structural constraint on the slot-variant IE precoding to maintain a constant precoder throughout the block. A novel linear precoder for IE is further presented, and we prove that the proposed slot-variant and slot-invariant IE precoding share an identical solution when the number of symbol slots does not exceed the number of users. Numerical simulations demonstrate that the proposed precoders achieve a significant complexity reduction compared against benchmark schemes, without sacrificing performance.
%V 11
%A Junwen Yang
%A Ang Li
%A Xuewen Liao
%A Christos Masouros
%A A Lee Swindlehurst
%K Precoding, Interference, Symbols, Signal to noise ratio,
Vectors, Optimization, Minimization
%N 21
%J IEEE Internet of Things Journal
%D 2024
%I Institute of Electrical and Electronics Engineers (IEEE)
%L discovery10195960
%P 35519-35535
%T Block-Level MU-MISO Interference Exploitation Precoding: Optimal Structure and Explicit Duality
%O This version is the author-accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.