| 摘要 |
<p>A system and method for dectecting discontinuous transmission (DTX) frames. The inventive method includes the steps of receiving data transmitted in a pluralitz of frames (62); classifzing each of the frames (63); analyzing the classification of a number of successive frames of the received data and providing a metric with respect thereto; and determining, in response to the metric, if a frame is a discontinuous frame (66). In the illustrative embodiment, the step of classifzing includes the step of error checking the frames using a cyclic redundancz check (CRC) error checking protocol. The received frames are classified as good frames (G), erasureframes (E), or discontinuous frames (D). A numerical value is assigned toe ach of the frames based on the classification thereof. Next, the frames are filtered tp provice an output Yn=Yn-1+Xn where 'n' is a frame number, Yn is the filter output for a given frame n, Yn-1 is the filter output for a previous frame, and Xn is a stream of input frames. A threshold is set for the output Yn to facilitate the detection of discontinuous frames. That is, a detection of a discontinuous transmisson frame is indicated when a frame is classified as an 'erasure' and the filter output exceeds the threshold. On the detection of a discontinuous frame, the classification of the frame is changed from 'erasure' to 'discontinuous'. By reclassifying improperly classified erasure frames, the mobile receiver is inhibited from requesting retransmission of the frames of a change in the transmit power level. Consequently, network throughput and capacity are optimized and system power is conserved.</p> |
