Channel estimation in adaptive modulation systems

A device (20) for an adaptive modulation communication system, comprising:

• an input device (21) adapted to receive, from a communication channel, data encoded through a Forward Error Correction, FEC, code;
• a FEC decoder (23) connected downstream of the input device (21), for FEC decoding the received encoded data and providing error information determined by the FEC decoding;
• means (32a, 34a) for measuring first error information of said encoded data before FEC decoding said received encoded data;
• means (32b, 34b) for measuring second error information determined by said FEC decoder;
• means (25) for estimating a condition of the communication channel based on both said first error information and said second error information.

An adaptive modulation communication system, comprising a transmitter stage (40, 60) for transmitting over a communication channel data encoded through a Forward Error Correction code, said encoded data being modulated according to the communication channel conditions, wherein the system comprises a receiver stage (50, 70) including:

• an input device (21) adapted to receive, from the communication channel, the encoded data;
• a FEC decoder (23) connected downstream of the input device, for FEC decoding the received encoded data and providing error information determined by the FEC decoding;
• means (32a, 34a) for measuring first error information of said encoded data before FEC decoding said received encoded data;
• means (32b, 34b) for measuring second error information determined by said FEC decoder;
• means (25) for estimating a condition of the communication channel based on both said first error information and said second error information.