Abstract: An adaptive modulation scheme for two streams of information that have different characteristics; preferably voice and data. The voice and data are transmitted on two quadrature channels, the I and Q channels. The amount of power in the channels is adaptively varied. The voice is given all the power it needs for reliable communication over a binary phase shift keying system. The data can have higher data rates, using an M-ary amplitude modulation scheme. The data uses whatever variable amount of power is left after transmitting the voice. The data rate is changed by changing the constellation size, so that a higher bit rate is transmitted, but requiring higher power.