fig7 diagrammatically illustrates pertinent portions of exemplary embodiments of a transmitter that uses shaping techniques in the manner described generally above according to the invention the shaping device for example decoder element 71 is controlled by a shaping controller 72 according to a desired criterion in some embodiments the criterion or criteria can be implemented for example by a metric element such as one of the exemplary metric elements described above relative to fig3 u2013 6 in such embodiments the metric functions 35 43 51 and 63 serve as control information determiners that determine what control information will be applied to the shaping decoder any desired shaping method for example trellis shaping see 1 or convolutional spectral shaping see 8 and 9 can be implemented at 71 as described above the criterion or criteria of the metric element ensures that the shaping operation at 71 produces shaped information bits at 73 that result after mapping at 74 in a transmitted symbol stream according to the defined requirement s as discussed above when restrictions on the transmitted power over certain frequency bands apply a special e g notch filter can be used in the transmitter to attenuate the signal in these bands exemplary transmitter embodiments according to the invention can reduce the isi effect of these filters by using th preceding upstream of the filter a block diagram of exemplary transmitter embodiments according to the invention is shown in fig8 the isi.