Further, timing misalignments amongst carriers are effective only for large baudrates of carriers. When timing misalignments are relevant, a pre-compensation procedure shall preferably be used to limit the degradation effects on both the channel estimations and the precoding gains. 

The reliability test at step d) relies on the finding that when a co-channel carrier is present in the received signal, the phase estimation on successive pilot fields should yield a value which has a small standard deviation window, while on the other hand, when the signal is not present, the phase estimation should vary randomly between π and ~ π . According to these considerations, a coefficient is classified as being reliable (and, as a consequence, the corresponding carrier is detected at receiver 100) if the standard deviation of the estimated phase is below a certain predetermined value, for example but not limited to π /2. For the interfering waveform components received in the signal 110 at the receiver 100, the phase values are determined as offset values with respect to the absolute phase value that has been determined for the reference waveform 1. The offset value is for example computed by computing the difference between the average of the reference waveform component’s sequence of pilot field phase values, and the average of an interfering waveform component’s sequence of pilot field phase values. 

Since each beam is defined by its own signature (in a frequency-reuse fashion for large systems since the number of Walsh-Hadamard sequences is limited) and since the beams are fixed (in terms of coverage over the earth), the receiver shall know the signature of the neighbour beams and it should try to estimate ideally all of them. In order to have an accurate estimation of the channel value, all SF-Pilot fields in a superframe should be used (for example, in format 2 of DVB-S2x, 639 pilot fields are included in one superframe). 

In what follows a formal description of the detection/reliability estimation of step d) in accordance with embodiments with the invention is provided. Assuming that <¾=[<¾(), ... , Cy(L$_{pil}$ )] is the j-th signature (first field) of the i-th beam, j=l,. .., N$_{pil}$ and i=l,. . A$_{¾}$ , where N$_{p}$ is the number of pilot sequences (second field) in one frame (or alternatively, the number of pilot sequences contained in the desired length to be considered for the procedure) and L$_{pil}$ is the length of the SF- Pilot for which orthogonality is maintained for up to beams. 

In the particular case of format 2 and 3 of the annex E option of DVB-S2x, for example, Cy is composed by a Walsh-Hadamard sequence ,•= [ ¾ (1),. .., v,( Α / / •)], one for each beam, and a scrambling sequence =[y(l), ... , y( L$_{piI)}$ \, which is common for all beams but is changes depending on the pilot sequence in the frame. 

