A transmitter in a Digital Subscriber Line (DSL) system includes a rate encoder configured to generate a first set of encoded bits using a set of least significant bits, a trellis shaper configured to generate a second set of encoded bits using a most significant bit and the first set of encoded bits, a first constellation mapper configured to generate a first point described by integer coordinates in a complex plane based on the first set of encoded bits obtained from the rate encoder, a second constellation mapper configured to generate a second point described by integer coordinates in the complex plane after interleaving two bits from the second set of encoded bits obtained from the trellis shaper, and a merger module configured to merge the first point with the second point to generate a symbol. The symbol represents a third point described by integer coordinates in the complex plane.