A receiver (13) of user equipment, UE, (10) of a Universal Mobile Telecommunications System, UMTS, network receives a digitally encoded radio signal over a downlink (11) from a base station (12). A Digital Signal Processor, DSP, (14) of the UE (10) estimates BER of data bits of power control commands received in the signal during an out of synchronisation procedure. More specifically, the DSP (14) samples the amplitude with which the data bits are received and determines a ratio of functions of one or more moments of the sampled amplitudes. The DSP (14) then compares the determined ratio to one or more values of BER for different ratios in a look-up table to estimate BER.