Abstract: A method for communication includes transmitting first and second copies of a signal toward first and second satellite transponders, respectively, so as to cause the first and second satellite transponders to transmit respective first and second downlink signals with mutually-orthogonal linear polarizations toward a coverage region. A correction is applied to at least one of the first and second copies before transmitting the first and second copies. The correction is selected so as to remove a frequency offset between the first and second downlink signals and cause the first and second downlink signals to have a constant phase offset in at least some of the coverage region.

Abstract: A method for communication over a communication channel includes processing input data, which is accepted at a first variable bit rate, so as to produce output data that is encoded with a Forward Error Correction (FEC) code and has a second bit rate that matches an available bit rate of the communication channel. The output data is transmitted over the communication channel at the available bit rate. The output data is received from the communication channel and decoded so as to reconstruct the input data.