239 results about "Keying" patented technology

Disclosed is a method and an apparatus for channel estimation regarding electromagnetic wave multi-path characteristics between a sender and a receiver by using a chirp signal. The method includes the steps of (a) multiplying a received composite signal by a narrowband chirp-shift-keying signal or narrowband multiple center-frequency-chirp signal generated by the receiver itself and outputting a sum of individual frequency components resulting from difference in distance of multiple paths for up-chirp and down-chirp signal portions of a chirp-shift-keying signal, respectively, the received composite signal being formed by generating narrowband chirp-shift-keying signals or narrowband multiple center-frequency-chirp signals by the sender, sending the signals by a transmission antenna, receiving the signals by a reception antenna of the receiver via a multi-path channel, superimposing the signals, and adding the signals; (b) multiplying outputs of the up-chirp and down-chirp signal portions of the sum of individual frequency components and calculating a tolerance frequency output; (c) compensating for a frequency tolerance of the sum of individual frequency components by using the tolerance frequency output and generating a frequency compensation output; (d) compensating for discontinuity of chirp-shift-keying signals resulting from use of the narrowband chirp-shift-keying signals or the narrowband multiple center-frequency-chirp signals regarding the frequency compensation output and generating a discontinuity compensation output having no discontinuity; (e) decomposing the discontinuity compensation output into individual multi-path signals by using a frequency analysis method; and (f) extracting an attenuation component and a time delay component caused by the multi-path channel from the individual multi-path signals by using a size of frequency components of each frequency.

The invention relates to a three-dimensional real-time tracking method and system for an indoor moving target. The method comprises the steps: at a transmitting stage, adopting ultra-wideband signals modulated on the basis of OOK (On-Off Keying) as positioning detection signals; at a receiving stage, carrying out TOA (Time Of Arrival) time delay estimation by adopting an energy block and coherence based time delay estimation method or a threshold method based time delay estimation method, and achieving three-dimensional positioning by a TDOA (Time Difference Of Arrival) based three-dimensional positioning method. According to the method and the system, in view of different designs and environmental requirements, two methods, i.e., the energy block and coherence based time delay estimation method and the threshold method based time delay estimation method are adopted, so that the operation time is short, and real-time positioning can be carried out; different three-dimensional positioning methods are adopted according to different numbers of probes, so that relatively high positioning accuracy can be achieved, and the adaptability is relatively high.