Wireless communications systems and methods for direct memory access and buffering of digital signals for multiple user detection
First Claim
1. A communications device for detecting user transmitted symbols encoded in spread spectrum waveforms (hereinafter “
- user waveforms”
) comprising a digital signal processor (hereinafter “
DSP”
) that processes user waveforms to determine characteristics thereof, the DSP having an associated memory and an associated direct memory access (hereinafter “
DMA”
) controller that controls access to that memory, a programmable logic device (hereinafter “
PLD”
) that is coupled to the DMA controller and that configures it to move data relating to user waveform characteristics from the memory to a buffer external to the DSP.
6 Assignments
0 Petitions
Accused Products
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.
101 Citations
8 Claims
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1. A communications device for detecting user transmitted symbols encoded in spread spectrum waveforms (hereinafter “
- user waveforms”
) comprisinga digital signal processor (hereinafter “
DSP”
) that processes user waveforms to determine characteristics thereof, the DSP having an associated memory and an associated direct memory access (hereinafter “
DMA”
) controller that controls access to that memory,a programmable logic device (hereinafter “
PLD”
) that is coupled to the DMA controller and that configures it to move data relating to user waveform characteristics from the memory to a buffer external to the DSP. - View Dependent Claims (2, 3, 4, 5)
- user waveforms”
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6. A communications device for detecting user transmitted symbols encoded in spread spectrum waveforms (hereinafter “
- user waveforms”
) comprisinga first-in first-out buffer comprising a dual-port random access memory, a digital signal processor (hereinafter “
DSP”
) that processes user waveforms to determine characteristics thereof, the DSP having an associated memory and an associated direct access memory (hereinafter “
DMA”
) controller that controls access to that memory,a programmable logic device (hereinafter “
PLD”
) that is coupled to the DMA controller and that configures it to move data relating to user waveform characteristics from the memory to the buffer external to the DSP. - View Dependent Claims (7, 8)
- user waveforms”
Specification
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- Resources
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Current AssigneeMercury Systems, Incorporated
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Original AssigneeMercury Computer Systems Incorporated
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InventorsMajchrzak, David E., Jacques, Kathleen J., Dunn, Ian N., Jenkins, William J., Lauginiger, Frank P., Cantrell, Paul E., Oates, John H., Fuchs, Alden J., Imperiali, Steven R., Vinskus, Michael J., Cifric, Mirza, Greene, Jonathan E.
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Granted Patent
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Time in Patent OfficeDays
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Field of Search
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US Class Current711/104
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CPC Class CodesH04B 1/707 using direct sequence modul...H04B 1/7093 Matched filter typeH04B 1/7105 Joint detection techniques,...H04B 1/71052 using decorrelation matrixH04B 1/71075 Parallel interference cance...H04B 1/7115 Constructive combining of m...H04B 2201/70707 Efficiency-related aspectsH04B 2201/70711 with modular structure
