A microwave radio terminal capable of multiple gigabits/sec bit rate is provided. The radio terminal may use QAM modulation, including the two lowest modulation formats of BPSK and QPSK. The serial bit stream, including forward error correction (FEC) and all other overhead, is prepared in a digital circuit, such as a filed programmable gate array (FPGA) and is output serially, using SERDES devices inside the FPGA, as two separate channels known as “I-channel” and “Q-channel”.