摘要:
A method of improving bandwidth of wireless CDMA systems by shuffling the rows of a Hadamard function in a pseudo-random manner. A Hadamard function is used to provide orthogonality between users. The orthogonal waveforms are used to prevent interference from different users sharing the same cell as well as multiple channels from the same user. The rows of the Hadamard function are shuffled in a pseudo-random manner. This effectively maximally spreads the spectral density of the transmitted signal out across the available spectrum. These codes are pre-computed and stored in lookup tables of mobile wireless devices. The data signals are modulated by one set of codes. Thereby, one data bit can be transmitted per chip.
摘要:
An autocorrelation filter for use with a spread spectrum receiver. The autocorrelation filter can be used as a prefilter stage to reduce phase distortion present in a spread spectrum signal. The autocorrelation filter can be used to process the output from a lattice filter. The lattice filter is configured to remove magnitude distortion from the spread spectrum signal. The autocorrelation filter performs a series of correlations on the output of the lattice filter. The results of these correlations are integrated over a period of time to generate a running impulse response for characterizing and removing the phase distortion in the spread spectrum signal.
摘要:
A method and apparatus for estimating the motion of an image region (the “center” region) from a source video frame to a target video frame. The motion estimation is locally constrained in that the estimated motion of the “center region” is affected by the estimated motion of neighboring regions. Advantageously, this may reduce common motion matching problems such as false and ambiguous matches. In one embodiment, the locally-constrained motion estimation may be implemented by biasing an error map of the center region using error maps of the neighboring regions.
摘要:
The present invention comprises a computer implemented process and system for rendering curves or surfaces as 3D graphics on a display. The system of the present invention includes a computer system having a processor, a bus, and a 3D graphics rendering pipeline. The curves or surfaces are modeled by non-uniform rational B-splines (NURBS). The process of the present invention functions by receiving a NURBS model for rendering from a software program running on the host processor. The NURBS model defines a curve or surface. The process of the present invention efficiently converts the NURBS model to a Bezier model using the hardware of the graphics rendering pipeline. The Bezier model describes the same curve or surface. The process of the present invention subsequently generates a plurality of points on the curve or surface using the Bezier model and the graphics rendering pipeline. The points are then used by the graphics rendering pipeline to render the curve or surface defined by the Bezier model. Alternatively, a NURBS model is directly evaluated into a plurality of points on a curve or surface, and in turn, rendered into the curve or surface. This direct rendering of the NURBS model is implemented using the graphics rendering pipeline.