Wireless communications systems and methods for virtual user based multiple user detection utilizing vector processor generated mapped cross-correlation matrices
First Claim
1. A method for detecting user transmitted symbols encoded in physical user waveforms comprisingdecomposing each of one or more physical user waveforms into one or more respective virtual user waveforms, each virtual user waveform representing at least a portion of a symbol encoded in the respective physical user waveform,determining cross-correlations among the virtual user waveforms as a function of one of more characteristics of the respective physical user waveforms, the determining step includes generating a first matrix that stores the cross-correlations among the virtual user waveforms,generating, from the first matrix, a second matrix representing a cross-correlation of the physical user waveforms,generating estimates of the symbols encoded in the physical user waveforms as a function of the cross-correlations, the step of generating the estimates of the symbols includes generating those estimates from the second matrix.
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Abstract
The invention provides methods and apparatus for multiple user detection (MUD) processing that have application, for example, in improving the capacity CDMA and other wireless base stations. One aspect of the invention provides a multiprocessor, multiuser detection system for detecting user transmitted symbols in CDMA short-code spectrum waveforms. A first processing element generates a matrix (hereinafter, “gamma matrix”) that represents a correlation between a short-code associated with one user and those associated with one or more other users. A set of second processing elements generates, e.g., from the gamma matrix, a matrix (hereinafter, “R-matrix”) that represents cross-correlations among user waveforms based on their amplitudes and time lags. A third processing element produces estimates of the user transmitted symbols as a function of the R-matrix.
66 Citations
13 Claims
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1. A method for detecting user transmitted symbols encoded in physical user waveforms comprising
decomposing each of one or more physical user waveforms into one or more respective virtual user waveforms, each virtual user waveform representing at least a portion of a symbol encoded in the respective physical user waveform, determining cross-correlations among the virtual user waveforms as a function of one of more characteristics of the respective physical user waveforms, the determining step includes generating a first matrix that stores the cross-correlations among the virtual user waveforms, generating, from the first matrix, a second matrix representing a cross-correlation of the physical user waveforms, generating estimates of the symbols encoded in the physical user waveforms as a function of the cross-correlations, the step of generating the estimates of the symbols includes generating those estimates from the second matrix.
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5. A system for detecting user transmitted symbols encoded in physical user waveforms comprising
one or more processors coupled with an apparatus that receives the physical user waveforms, the one or more processors generating one or more virtual user waveforms representing each of the transmitted physical user waveforms, each virtual user waveform representing at least a portion of a symbol encoded in its respective physical user waveform, one or more vector processors coupled with the one or more processors, the one or more vector processors generating cross-correlations among the one or more virtual user waveforms as a function of one or more characteristics of the respective physical user waveforms, wherein the one or more vector processors generate the cross-correlations among the virtual user waveforms, and store those cross-correlations in a first matrix, wherein the one or more processors generate a second matrix representing a cross-correlation of the physical user waveforms as a function of the first matrix, the one or more processors generating estimates of the symbols encoded in the physical user waveforms as a function of the cross-correlations, wherein the one or more processors generate the estimates of the symbols as a function of the second matrix.
- 10. A system for detecting user transmitted symbols encoded in spread spectrum waveforms, comprising a vector processor that generates cross-correlations among one or more user waveforms as a function of block-floating integer representations of one or more characteristics of those waveforms.
Specification