| 摘要 |
PROBLEM TO BE SOLVED: To save power by performing VOX (voice operated transmission) control for interrupting transmission for a frame without voice data and to accurately perform VOX judgement for the presence/absence of voice data on a reception side in the radio communication system of a digital automobile telephone set or the like. SOLUTION: In a reference power measurement circuit 32, phases are matched by inversely rotating all or part of the pilot signals of the received frame by the theoretical value of the pilot signals respectively, common-mode vector synthesis is performed, averaging is performed by a synthetic symbol number and the absolute value of the averaged vector is defined as desired signal reference power X. Also, a fading vector is obtained by using pilots in front and at the back of a data part in a fading compensation circuit 33, the phases are matched by inversely rotating fading compensated data by a judgement value in a power measurement circuit 34, the common-mode vector synthesis is performed, the averaging is performed by the synthetic symbol number and the absolute value of the averaged vector is defined as reception signal power Y. In a judgement circuit 30, the desired signal reference power X and the reception signal power Y are compared and VOX is judged. |
