A method of adaptive equalisation comprising the steps of: Receiving a first signal transmitted via a channel in which the first received signal differs from the first transmitted signal due to channel distortion and/or noise, the first signal comprising a sequence of symbols encoded by inphase and quadrature components; repeating the steps of filtering a portion of the received first signal using a first filter having a plurality of first filter coefficients to obtain a filtered first signal; determining the likely inphase and quadrature components of the first transmitted signal; determining a first error signal in dependence upon the difference between the likely inphase and quadrature components and the inphase and quadrature components of the filtered first signal; updating the first filter coefficients to reduce said first error signal; and locking said first filter coefficients when the average first error signal is less than a predetermined threshold; and characterised in that the method further comprises receiving a second signal transmitted via the channel in which the second received signal differs from the second transmitted signal due to channel distortion and/or noise, the second signal comprising a sequence of symbols encoded by inphase and quadrature components; continually repeating the steps of filtering a portion of the received second signal using said first filter with said locked filter coefficients to obtain a first filtered second signal; filtering the first filtered second signal using a second filter having a plurality of second filter coefficients to obtain a second filtered second signal; determining the likely inphase and quadrature components of the second transmitted signal; determining a second error signal in dependence upon the difference between the likely inphase and quadrature components and the inphase and quadrature components of the second filtered second signal; updating the second filter coefficients to reduce said second error signal; and wherein the number of bits encoded by the symbols of the first signal in an initial modulation mode is fewer than the number of bits encoded by the symbols of the second signal in a subsequent modulation mode. Receiving a first signal transmitted via a channel in which the first received signal differs from the first transmitted signal due to channel distortion and/or noise, the first signal comprising a sequence of symbols encoded by inphase and quadrature components; repeating the steps of filtering a portion of the received first signal using a first filter having a plurality of first filter coefficients to obtain a filtered first signal; determining the likely inphase and quadrature components of the first transmitted signal; determining a first error signal in dependence upon the difference between the likely inphase and quadrature components and the inphase and quadrature components of the filtered first signal; updating the first filter coefficients to reduce said first error signal; and locking said first filter coefficients when the average first error signal is less than a predetermined threshold; filtering a portion of the received first signal using a first filter having a plurality of first filter coefficients to obtain a filtered first signal; determining the likely inphase and quadrature components of the first transmitted signal; determining a first error signal in dependence upon the difference between the likely inphase and quadrature components and the inphase and quadrature components of the filtered first signal; updating the first filter coefficients to reduce said first error signal; and locking said first filter coefficients when the average first error signal is less than a predetermined threshold; and characterised in that the method further comprises receiving a second signal transmitted via the channel in which the second received signal differs from the second transmitted signal due to channel distortion and/or noise, the second signal comprising a sequence of symbols encoded by inphase and quadrature components; continually repeating the steps of filtering a portion of the received second signal using said first filter with said locked filter coefficients to obtain a first filtered second signal; filtering the first filtered second signal using a second filter having a plurality of second filter coefficients to obtain a second filtered second signal; determining the likely inphase and quadrature components of the second transmitted signal; determining a second error signal in dependence upon the difference between the likely inphase and quadrature components and the inphase and quadrature components of the second filtered second signal; updating the second filter coefficients to reduce said second error signal; filtering a portion of the received second signal using said first filter with said locked filter coefficients to obtain a first filtered second signal; filtering the first filtered second signal using a second filter having a plurality of second filter coefficients to obtain a second filtered second signal; determining the likely inphase and quadrature components of the second transmitted signal; determining a second error signal in dependence upon the difference between the likely inphase and quadrature components and the inphase and quadrature components of the second filtered second signal; updating the second filter coefficients to reduce said second error signal; and wherein the number of bits encoded by the symbols of the first signal in an initial modulation mode is fewer than the number of bits encoded by the symbols of the second signal in a subsequent modulation mode.