Integer-Forcing Linear Receivers Based on Lattice Reduction Algorithms

A new architecture called integer-forcing (IF) linear rece iver has been recently proposed for multiple-input multiple-output (MIMO) fading channels, wherein an approp riate integer linear combination of the received symbols has to be computed as a part of the decoding process. Till date , the only known solution to finding these integers is based on exhaustive search. In this paper, we propose a met hod based on HKZ and Minkowski lattice basis reduction algorithms to obtain the integer coefficients for the IF receiver. We show that the proposed method provides a lower bound on the ergodic rate, and achieves the f ull receive diversity. Furthermore, we establish the connection between the proposed IF linear receivers and lat tice reduction aided MIMO detectors (with equivalent complexity), and point out the advantages of the former clas s of receivers over the latter. For the 2× 2 and4× 4 MIMO channels, we compare the codeword error rate (CER) and b it error rate (BER) of the proposed approach with that of other linear receivers. Simulation results sho w that the proposed approach outperforms the zero-forcing (ZF) receiver, minimum mean square error (MMSE) receiver, a nd the lattice reduction aided MIMO detectors.