BCH and LDPC coded wide-band modem for 21-GHz band satellite broadcasting system

The 21-GHz band has been allocated for Ka-band BSS and has a wide bandwidth from 21.4 to 22.0GHz. The 600MHz spectrum allocation is suitable for UHDTV satellite broadcasting. As a countermeasure for rain attenuation due to Ka-band characteristics, a strong forward error correction scheme must be implemented for stable signal reception. We have implemented the concatenated code of BCH and LDPC in the Q/8PSK wide-band modem, whose maximum symbol rate is 250Mbaud. Through measurements, we confirmed clear coding gain against QPSK and 8PSK with no FEC under AWGN.