DIGITAL BROADCASTING RECEIVING DEVICE

摘要

PROBLEM TO BE SOLVED: To appropriately display reception quality in a stepwise level for received electric field strength in a comparatively wide range in a digital broadcasting receiving device where a plurality of narrow band signals are combined and broadcasting electric waves from a narrow band to a wide band are selectively received. SOLUTION: The digital broadcasting receiving device changes a plurality of thresholds for judging reception quality (C/N value) in accordance with band width which is selected at present and classifies detected reception quality into reception quality levels in a plurality of steps, which are judged by a plurality of the thresholds. The classified reception quality levels are displayed on a display screen at a display mode which changes stepwise. (a) The C/N value is obtained from an error rate (BER) at every modulation system and a convolution coding rate. (b) A variance value is obtained from a reception coordinate of a previously known pilot signal based on a constellation of received data and it is converted into the C/N value. (c) The C/N value is obtained by taking a ratio of received power and thermal noise. COPYRIGHT: (C)2005,JPO&NCIPI