connected to the first inputs of p inputs of summer som1 registers rr1 to rrp can make up a delay register with a clock of period t the threshold level control input of detector ds is connected to the output of the mean value calculating circuit 10 the elements of the schematic shown in fig3 which have just been described constitute one part of a decision feedback transversal filter with decision in the loop the other part of the filter must comprise a circuit to compute the multiplier coefficients a1 to al and bp to b1 we will now describe this computing circuit the output of summer som2 is connected to an estimation circuit ce whose output is connected to a multiplier c to whose second input is applied the value of a coefficient u the output of multiplier c is connected to the first inputs of a first series of multipliers d1 to dl and of a second series of multipliers e1 to ep the second inputs of multipliers d1 to dl are respectively connected to the outputs of registers rd1 to rdl the second inputs of multipliers e1 to ep are respectively connected to the outputs of registers rr1 to rrp the outputs of multipliers d1 to dl are respectively connected to the.