(color online) Discretely-modulated eight-state protocol with LOCM in finite-size scenario in the case of heterodyne detection, where V_A = 0.25, η = 0.6, υ_el = 0.05, and β = 0.95. Solid curves indicate the original eight-state protocol while the dashed curves represent the scenario with an LOCM (where the two parameters are set to λ = 0.3 and τ = 0.45). From left to right, the first eight curves correspond to the finite-size scenario of block length N = 10⁸, 10¹⁰, 10¹², 10¹⁴ respectively, and the last two curves represent the asymptotic scenario.