Data transmission with non-uniform distribution of data rates for a multiple-input multiple-output (MIMO) system
First Claim
1. A method for determining data rates for a plurality of data streams to be transmitted via a plurality of transmission channels in a multi-channel communication system, comprising:
- determining a required signal-to-noise-and-interference ratio (SNR) for each of a plurality of data rates to be used for the plurality of data streams, wherein at least two of the data rates are unequal;
determining an effective SNR for each of the plurality of data streams based in part on successive interference cancellation processing at a receiver to recover the plurality of data streams;
comparing the required SNR for each data stream against the effective SNR for the data stream; and
determining whether or not the plurality of data rates are supported based on results of the comparing.
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Accused Products
Abstract
Techniques to determine data rates for a number of data streams transmitted via a number of transmission channels (or transmit antennas) in a multi-channel (e.g., MIMO) communication system. In one method, the “required” SNR for each data rate to be used is initially determined, with at least two data rates being unequal. The “effective” SNR for each data stream is also determined based on the received SNR and successive interference cancellation processing at the receiver to recover the data streams. The required SNR for each data stream is then compared against its effective SNR. The data rates are deemed to be supported if the required SNR for each data stream is less than or equal to its effective SNR. A number of sets of data rates may be evaluated, and the rate set associated with the minimum received SNR may be selected for use for the data streams.
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Citations
31 Claims
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1. A method for determining data rates for a plurality of data streams to be transmitted via a plurality of transmission channels in a multi-channel communication system, comprising:
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determining a required signal-to-noise-and-interference ratio (SNR) for each of a plurality of data rates to be used for the plurality of data streams, wherein at least two of the data rates are unequal;
determining an effective SNR for each of the plurality of data streams based in part on successive interference cancellation processing at a receiver to recover the plurality of data streams;
comparing the required SNR for each data stream against the effective SNR for the data stream; and
determining whether or not the plurality of data rates are supported based on results of the comparing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
where SNReff (k) is the effective SNR for the data stream recovered in stage k, SNRrx is the received SNR, NT is the number of transmit antennas used for data transmission, and NR is the number of receive antennas.
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9. The method of claim 4, further comprising:
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evaluating a plurality of sets of data rates; and
selecting a rate set associated with a minimum received SNR for use for the plurality of data streams.
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10. The method of claim 9, wherein the data rates in each rate set are selected to achieve a specified overall spectral efficiency.
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11. The method of claim 1, wherein the required SNR for each data rate is determined based on a look-up table.
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12. The method of claim 1, wherein the plurality of data rates are deemed to be supported if the required SNR for each data rate is less than or equal to the effective SNR for the data rate.
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13. The method of claim 1, wherein the communication system implements orthogonal frequency division multiplexing (OFDM).
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14. A method for determining data rates for a plurality of data streams to be transmitted over a plurality of transmit antennas in a multiple-input multiple-output (MIMO) communication system, comprising:
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determining an operating signal-to-noise-and-interference ratio (SNR) indicative of an operating condition of the MIMO system;
determining a required SNR for each of a plurality of data rates to be used for the plurality of data streams, wherein at least two of the data rates are unequal and wherein the plurality of data rates are selected to achieve a specified overall spectral efficiency;
determining an effective SNR for each of the plurality of data streams based on the operating SNR and successive interference cancellation processing technique at a receiver to recover the plurality of data streams;
comparing the required SNR for each data stream against the effective SNR for the data stream; and
determining whether or not the plurality of data rates are supported based on results of the comparing.
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15. A method for determining data rates for a plurality of data streams to be transmitted via a plurality of transmission channels in a multi-channel communication system, comprising:
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determining a received SNR indicative of an operating condition of the plurality of transmission channels;
determining an effective SNR for each of the plurality of data streams based on the received SNR and successive interference cancellation processing at a receiver to recover the plurality of data streams; and
determining a data rate for each data stream based on the effective SNR for the data stream, wherein at least two of the data rates are unequal. - View Dependent Claims (16, 17, 18)
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19. A memory communicatively coupled to a digital signal processing device (DSPD) capable of interpreting digital information to:
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determine a required signal-to-noise-and-interference ratio (SNR) for each of a plurality of data rates to be used for a plurality of data streams to be transmitted via a plurality of transmission channels in a multi-channel communication system, wherein at least two of the data rates are unequal;
determine an effective SNR for each of the plurality of data streams based in part on successive interference cancellation processing at a receiver to recover the plurality of data streams;
compare the required SNR for each data stream against the effective SNR for the data stream; and
determine whether or not the plurality of data rates are supported based on results of the comparison.
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20. An apparatus in a multi-channel communication system, comprising:
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means for determining a required signal-to-noise-and-interference ratio (SNR) for each of a plurality of data rates to be used for a plurality of data streams to be transmitted via a plurality of transmission channels, wherein at least two of the data rates are unequal;
means for determining an effective SNR for each of the plurality of data streams based in part on successive interference cancellation processing at a receiver to recover the plurality of data streams;
means for comparing the required SNR for each data stream against the effective SNR for the data stream; and
means for determining whether or not the plurality of data rates are supported based on results of the comparing. - View Dependent Claims (21, 22, 23, 24, 25)
means for evaluating a plurality of sets of data rates; and
means for selecting a rate set associated with a minimum received SNR for use for the plurality of data streams.
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22. The apparatus of claim 20, wherein the multi-channel communication system is a multiple-input multiple-output (MIMO) communication system.
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23. The apparatus of claim 22, wherein the MIMO system implements orthogonal frequency division multiplexing (OFDM).
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24. A base station comprising the apparatus of claim 20.
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25. A wireless terminal comprising the apparatus of claim 20.
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26. A transmitter unit in a multiple-input multiple-output (MIMO) communication system, comprising:
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a controller operative to determine a plurality of data rates for a plurality of data streams to be transmitted over a plurality of transmit antennas by determining a required signal-to-noise-and-interference ratio (SNR) for each of the plurality of data rates, wherein at least two of the data rates are unequal, determining an effective SNR for each of the plurality of data streams based in part on successive interference cancellation processing technique at a receiver to recover the plurality of data streams, comparing the required SNR for each data stream against the effective SNR for the data stream, and determining whether or not the plurality of data rates are supported based on results of the comparing;
a transmit (TX) data processor operative to process each data stream with the determined data rate to provide a respective symbol stream; and
one or more transmitters operative to process a plurality of symbol streams for the plurality of data streams to provide a plurality of modulated signals suitable for transmission over the plurality of transmit antennas. - View Dependent Claims (27, 28, 29)
evaluating a plurality of sets of data rates, and selecting a rate set associated with a minimum received SNR. -
28. A base station comprising the transmitter unit of claim 26.
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29. A wireless terminal comprising the transmitter unit of claim 26.
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30. A transmitter apparatus in a multiple-input multiple-output (MIMO) communication system, comprising:
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means for determining a required signal-to-noise-and-interference ratio (SNR) for each of a plurality of data rates to be used for a plurality of data streams to be transmitted over a plurality of transmit antennas in the MIMO system, wherein at least two of the data rates are unequal;
means for determining an effective SNR for each of the plurality of data streams based in part on successive interference cancellation processing at a receiver to recover the plurality of data streams;
means for comparing the required SNR for each data stream against the effective SNR for the data stream;
means for determining whether or not the plurality of data rates are supported based on results of the comparison;
means for processing each data stream to provide a respective symbol stream; and
means for processing a plurality of symbol streams for the plurality of data streams to provide a plurality of modulated signals suitable for transmission over the plurality of transmit antennas.
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31. A receiver unit in a multiple-input multiple-output (MIMO) communication system, comprising:
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a receive (RX) MIMO processor operative to receive and process a plurality of received symbol streams using successive interference cancellation processing to provide a plurality of detected symbol streams for a plurality of transmitted data streams, one detected data stream for each stage of the successive interference cancellation processing; and
a RX data processor operative to process each detected symbol stream to provide a corresponding decoded data stream, and wherein data rates for the plurality of transmitted data streams are determined by determining a received signal-to-noise-and-interference ratio (SNR) indicative of an operating condition of the communication system, determining an effective SNR for each of the plurality of data streams based on the received SNR and the successive interference cancellation processing, and determining the data rate for each data stream based on the effective SNR, and wherein at least two of the data rates are unequal.
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Specification