381 results about "Word length" patented technology

An oversampling pulse oximeter includes an analog to digital converter with a sampling rate sufficient to take multiple samples per source cycle. In one embodiment, a pulse oximeter (100) includes two or more light sources (102) driven by light source drives (104) in response to drive signals from a digital signal processing unit (116). The source drives (104) may drive the sources (102) to produce a frequency division multiplex signal. The optical signals transmitted by the light sources (102) are transmitted through a patient's appendage (103) and impinge on a detector (106). The detector (106) provides an analog current signal representative of the received optical signals. An amplifier circuit (110) converts the analog current signal to an analog voltage signal in addition to performing a number of other functions. The amplifier circuit (110) outputs an analog voltage signal which is representative of the optical signals from the sources (102). This analog voltage signal is received by a fast A / D converter (112) which samples the analog voltage signal to generate a digital voltage signal which can be processed by the digital signal processing unit (116). The fast A / D converter (112) operates at a rate sufficient to take multiple samples per source cycle and may have a sampling frequency, for example, of over 41 kHz. The digital signal processing unit (116) implements software for averaging the samples over a source cycle for improved measurement consistency, improved signal to noise ratio and reduced A / D converter word length.

In a method of demodulating and decoding an encoded interleaved signal, a received encoded interleaved signal is demodulated, thereby producing soft-decision demodulated output words. Thereafter, the soft-decision demodulated output words are de-interleaved and scaled, thereby producing de-interleaved and scaled words. The scaling is performed for a plurality of successively demodulated output words at a time, thereby applying a scale factor that is substantially constant over the entire span of an interleaving frame. The de-interleaved and scaled words are word-length-reduced words. Finally, the de-interleaved and scaled words are decoded.

The invention relates to a distributed target tracking method suitable under a camera network, and belongs to the technical field of the camera network, distributed processing and target tracking application. The method includes the steps of performing motion prediction and estimation for a target monitored by each camera using square root cubature information filtering; performing information interaction among the cameras through communication, and then performing distributed data fusion of the information using a mean consistency method; and finally, obtaining a stable tracking result through multiple iterations so as to achieve target tracking under the camera network. Compared with the prior art, the method of the invention takes relevant noise between process noise and measurement noise into consideration so that a system with the presence of the relevant noise can also achieve the application of target tracking; the use of the square root cubature information filtering allows the system to avoid the falling into the finite word-length problem of a processor, and meanwhile, the combination of the weighted mean consistency method allows the application in a distributed environment by the system; and the robustness of the method is enhanced while the tracking accuracy is improved.