Ordered successive interference cancellation receiver processing for multipath channels
First Claim
1. A method for processing a plurality of received symbol streams to recover a plurality of transmitted symbol streams, comprising:
- processing the received symbol streams to provide a plurality of detected symbol streams, wherein each detected symbol stream is an estimate of a corresponding transmitted symbol stream;
determining a metric for each of the plurality of detected symbol streams as a function of a frequency selective response of one or more transmission channels used to transmit a detected symbol stream;
selecting the detected symbol stream associated with a best metric for recovery; and
processing the selected detected symbol stream to recover a transmitted symbol stream and obtain data transmitted for the transmitted symbol stream.
1 Assignment
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Accused Products
Abstract
Techniques to process a number of “received” symbol streams in a Multiple-Input Multiple-Output (MIMO) system with multipath channels such that improved performance may be achieved when using successive interference cancellation (SIC) processing. In an aspect, metrics indicative of the quality or “goodness” of a “detected” symbol stream are provided. These metrics consider the frequency selective response of the multipath channels used to transmit the symbol stream. For example, the metrics may relate to (1) an overall channel capacity for all transmission channels used for the symbol stream, or (2) an equivalent signal-to-interference noise ratio (SNR) of an Additive White Gaussian Noise (AWGN) channel modeling these transmission channels. In another aspect, techniques are provided to process the received symbol streams, using SIC processing, to recover a number of transmitted symbol streams. The particular order in which the symbol streams are recovered is determined based on the metrics determined for symbol streams detected at each SIC processing stage.
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Citations
43 Claims
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1. A method for processing a plurality of received symbol streams to recover a plurality of transmitted symbol streams, comprising:
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processing the received symbol streams to provide a plurality of detected symbol streams, wherein each detected symbol stream is an estimate of a corresponding transmitted symbol stream; determining a metric for each of the plurality of detected symbol streams as a function of a frequency selective response of one or more transmission channels used to transmit a detected symbol stream; selecting the detected symbol stream associated with a best metric for recovery; and processing the selected detected symbol stream to recover a transmitted symbol stream and obtain data transmitted for the transmitted symbol stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method for processing a plurality of received symbol streams to recover a plurality of transmitted symbol streams, comprising:
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processing the received symbol streams to provide a plurality of detected symbol streams; determining a metric for each of the plurality of detected symbol streams as a function of a frequency selective response of a plurality of frequency subehannels used to transmit a detected symbol stream; selecting the detectcd symbol stream associated with a best metric for recovery; processing the selected detected symbol stream to recover a transmitted symbol stream and obtain data transmitted for the transmitted symbol stream; deriving a plurality of modified symbol streams having estimated interference due to the recovered transmitted symbol stream approximately removed; and processing the modified symbol streams to recover another transmitted symbol stream. - View Dependent Claims (23, 24)
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25. A method for deriving a metric indicative of a received quality of a symbol stream transmitted via a multipath channel, comprising:
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estimating a post-detection signal-to-noise-and-interference ratio (SNR) of each of a plurality of frequency bins used to transmit the symbol stream; determining a channel capacity of each frequency bin based on the post-detection SNR; and accumulating channel capacities of the plurality of frequency bins to obtain an overall channel capacity indicative of the received quality of the symbol stream. - View Dependent Claims (26, 27, 28, 29, 30, 31)
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32. A digital signal processing device (DSPD) capable of interpreting digital information to:
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process a plurality of received symbol streams to provide a plurality of detected symbol streams, wherein each detected symbol stream is an estimate of a corresponding transmitted symbol stream; determine a metric for each detected symbol stream, wherein the metric considers a frequency selective response of one or more transmission channels used to transmit a detected symbol stream; select the detected symbol stream associated with a best metric for recovery; process the selected detected symbol stream to recover a transmitted symbol stream and obtain data transmitted for the transmitted symbol stream; derive a plurality of modified symbol streams having estimated interference due to the recovered transmitted symbol stream approximately removed; and process the modified symbol streams to recover another transmitted symbol stream.
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33. An apparatus, comprising:
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means for processing a plurality of received symbol streams to provide a plurality of detected symbol streams; means for determining a metric for each detected symbol stream, wherein the metric is a function of a frequency selective response of one or more transmission sub-channels used to transmit a detected symbol stream; means for selecting the detected symbol stream associated with a best metric for recovery; and means for processing the selected detected symbol stream to recover the a transmitted symbol stream and obtain data transmitted for the transmitted symbol stream. - View Dependent Claims (34, 35, 36, 37, 38)
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39. A receiver unit in a wireless communication system, comprising:
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a spatial processor operative to process a plurality of received symbol streams based on successive interference cancellation (SIC) processing, wherein for each stage of the SIC processing, to perform processing on a plurality of input symbol streams for a stage to provide one or more detected symbol streams, wherein the input symbol streams for a first stage are the received symbol streams, and wherein each detected symbol stream is an estimate of a corresponding transmitted symbol stream; a data processor operative to, for each stage of the SIC processing, process a selected detected symbol stream to recover a transmitted symbol stream and obtain data transmitted for the transmitted symbol stream; and a controller operative to, for each stage of the SIC processing except for a last stage, determine a metric for each of a plurality of detected symbol streams, select a detected symbol stream associated with a best metric for recovery in the stage, and provide an indication of the selected detected symbol stream for the stage, wherein the metric for each detected symbol stream is a function of a frequency selective response of one or more transmission channels used to transmit the detected symbol stream. - View Dependent Claims (40, 41, 42, 43)
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Specification