Link adaptation based on generic CINR measurement according to log-likelihood ratio distribution
AssigneeCisco Technology, Inc.
InventorsHang Jin, Hanqing Lou, Ahmadreza Hedayat
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Abstract
Techniques are provided to compute the carrier to interference-plus-noise ratio (CINR) in a wireless communication system using log-likelihood ratio (LLR) data generated from a received transmission. The LLR data are collected as they are sent from a detector to a forward error correction (FEC) decoder in a wireless communications device. In one embodiment, decision-aided LLR based CINR is computed using the decoded bits output from the FEC decoder as feedback. In another embodiment, blind LLR based CINR is computed without feedback. The CINR may be used to adjust a modulation and/or coding parameters associated with wireless communication between wireless communication devices.
Claims27
A method comprising:
- receiving at a first device a wireless transmission transmitted from a second device;
- generating log-likelihood ratio data from the received wireless transmission;
- computing mean and standard deviation values for subsets of the log-likelihood ratio data;
- computing a carrier to interference plus noise ratio (CINR) based on a summation of the ratios of the mean values to the standard deviation values of the subsets of the log-likelihood ratio data;
- and
- adjusting a modulation and/or coding parameter associated with the wireless transmission based on the CINR.
An apparatus comprising:
- a receiver that receives a wireless transmission transmitted from a second communication apparatus;
- a detector coupled to the receiver and configured to generate log-likelihood ratio data from the received wireless transmission;
- and
- a controller coupled to the detector and configured to:
- compute mean and standard deviation values for subsets of the log-likelihood ratio data;
- compute a carrier to interference plus noise ratio (CINR) based on a summation of the ratios of the mean values to the standard deviation values of the subsets of the log-likelihood ratio data;
- and
- generate adjustment data for a modulation and/or coding parameter associated with the wireless transmission based on the CINR.
A non-transitory computer readable media encoded with logic that when executed by a processor is operable to cause the processor to:
- generate log-likelihood ratio data associated with reception of a wireless transmission at a first device that is transmitted from a second device;
- compute mean and standard deviation values for subsets of the log-likelihood ratio data;
- compute a carrier to interference plus noise ratio (CINR) based on a summation of the ratios of the mean values to the standard deviation values of the subsets of the log-likelihood ratio data;
- and
- adjust a modulation and/or coding parameter associated with the wireless transmission based on the CINR.
Dependencies are inferred from the claim text.