Effects of Some Lattice Reductions on the Success Probability of the Zero-Forcing Decoder

Zero-forcing (ZF) decoder is a commonly used approximation solution of the integer least squares problem, which arises in communications and many other applications. Numerical simulations have shown that the LLL reduction can usually improve the success probability P_ZF of the ZF decoder. In this letter, we first rigorously show that both SQRD and V-BLAST, two commonly used lattice reductions, have no effect on P_ZF. Then, we show that LLL reduction can improve P_ZF when n = 2, we also analyze how the parameter δ in the LLL reduction affects the enhancement of PZF. Finally, an example is given which shows that the LLL reduction decrease P_ZF when n ≥ 3.