A device (20) for an adaptive modulation communication system is provided. The device (20) comprises an input device (21) adapted to receive, from a communication channel, data encoded through a FEC code. A FEC decoder (23) connected downstream of the input device (21) is also provided for FEC decoding the received encoded data and providing error information determined by the FEC decoding. The device according to the invention further comprises means for measuring first error information of the encoded data before FEC decoding the received encoded data, and means for measuring second error information determined by the FEC decoder (23). Means (25) for estimating a condition of the communication channel based on both the first error information and the second error information are also provided.