| 摘要 |
The figure shows a speech transmission link. This leads from a telephone (11) of a private network (13) via exchanges (14, 17) to a mobile node (19) with an antenna (20) and via a radio link (22) to a mobile telephone (12). A mobile (31) and a stationary measuring unit (32) which are disposed near to the telephones (11, 12) are used to evaluate the given transmission quality. The one measuring unit (31, 32) transmits a pre-defined sequence of human speech, prefixed by a synchronisation pattern, as a test signal. The respective other measuring unit (32, 31) recognises the synchronisation pattern and thereby defines the starting time of the following sequence. This sequence is divided up into a multiplicity of respective intermediate values in that time intervals are formed and their sound characteristics are digitised. All of the intermediate values are finally evaluated by a neural network in such a way that an evaluation of "quality good, average or poor" understandable to humans is achieved at the output of said network. It is important here that the neural network is first trained using data evaluated by test persons. <IMAGE> |
