Referring to a modulation technique that impresses a single bit on a baud, so that the bit rate is the same as the baud rate. Such a technique employs only two signal states. Binary phase-shift keying (BPSK) is an example of a unibit modulation scheme. Basic amplitude modulation (AM) and frequency modulation (FM) also are unibit in nature. See also AM, BPSK, dibit, FM, quadbit, and tribit.