| 摘要 |
PROBLEM TO BE SOLVED: To keep stable signal S/N ratio detection accuracy by solving the problem of a blind zone where a signal S/N ratio is not detected.SOLUTION: A signal S/N ratio calculator which calculates a signal S/N ratio from a replica correlation processing result obtained by replica correlation processing between a replica signal of a transmitted signal and a received signal includes a differentiation processing section (1) which outputs differentiation data by calculating an increase/decrease ratio of a signal level of the replica correlation processing result, an extraction processing section (2) which outputs post-extraction-processing data by extracting only a positive variation from the differentiation data, a one-cross integration processing section (3) which calculates a one-cross integration value from the post-extraction-processing data and outputs integration data representing the one-cross integration value, and an S/N ratio calculation processing section (4) which calculates a signal S/N ratio of a target echo from the integration data. |
