The　traditional　binary　frequency　shift　keying　(2FSK)　technology　cannot　adapt　to　the　attenuation　characteristic　of　low-voltage　power　line　carrier　(LPLC)　channel.　In　order　to　solve　this　problem,　by　using　discrete　short　time　Fourier　transform　and　high-order　moments　theory,　a　novel　signal-to-noise　estimation　algorithm,　which　can　be　used　in　time-frequency　analysis,　was　proposed.　Based　on　it,　a　multi-carrier　binary　frequency　shift　keying　technique　based　on　time-frequency　analysis　was　implemented.　Simulation　results　showed　that　the　precision　of　the　SNR　estimation　could　meet　the　need　of　the　LPLC　communication　system　in　practice　and　the　multi-carrier　system　gains　lower　error　rate　than　the　single-carrier　system　while　they　are　interfered　by　the　same　noise.