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US 2014/0112250 A1Published application
Method of interference cancellation and method of detection of erroneous neighbour cell measurements
AssigneeBlack Berry Limited
InventorStefan Bahrenburg
Life of this patent
Estimating the term…
Abstract
Methods of interference cancellation are provided. Channel estimation is performed with or without interference cancellation. Methods of detection of erroneous neighbor cell measurements are provided. The channel estimates for neighbour cells are processed to identify unreliable measurements.
Claims23
A method comprising:
- processing a signal to produce an interference cancellation component of a first cell;
- performing signal detection for a to be detected cell operating on a same frequency as the first cell based on the signal minus the interference cancellation component if the interference cancellation component has a power that is large enough compared to a total power of the signal as defined by a first threshold;
- performing signal detection for a to be detected cell based on the signal without having subtracted the interference component if the interference cancellation component has a power that is not large enough compared to the total power of the signal as defined by the first threshold.
A method comprising:
- processing a signal to produce a channel estimate in respect of a first cell, the channel estimate comprising a plurality of taps;
- removing certain taps from the channel estimate to leave remaining taps and then producing an interference cancellation component from the remaining taps;
- performing first signal detection of a to be detected cell operating on a same frequency as the first cell based on the signal minus the interference cancellation component to produce a first signal detection result;
- performing second signal detection of the to be detected cell based on the signal without having subtracted the interference cancellation component to produce a second signal detection result;
- selecting between the first signal detection result and the second signal detection result.
2 more elements
A method comprising:
- processing a signal to produce an interference cancellation component that is an estimate of a component of the signal that is due to a first cell by:
- generating a channel estimate for the first signal using a cell-specific code of a first cell to produce a channel estimate comprising a plurality of taps;
- removing certain taps from the channel estimate to produce a post-processed channel estimate;
- producing the interference cancellation component using post-processed channel estimate;
- performing channel estimation of a to be detected cell operating on a same frequency as the first cell based on the signal minus the interference cancellation component by:
- generating a channel estimate for the to be detected cell using a cell-specific code of the to be detected cell;
- removing certain taps from the channel estimate to produce a channel estimate with certain taps removed for the to be detected cell;
- the method further comprising at least one of:
- a) discarding the channel estimate with certain taps removed for the to be detected cell and/or reporting a lowest reportable value and/or processing a very small value and/or not reporting the channel estimate if a combined power of the taps of the channel estimate with certain taps removed that define a to be measured channel for the to be detected cell is below a total receive power for the signal by a threshold amount;
- and
- b) discarding the channel estimate with certain taps removed for the to be detected cell and/or reporting a lowest reportable value and/or processing a very small value and/or not reporting the channel estimate if a combined power of the taps of the channel estimate with certain taps removed for the first cell is small enough compared to a total receive power for the signal as defined by a threshold amount.
8 more elements
A method of processing a signal, the method comprising:
- obtaining a channel estimate for a cell, the channel estimate comprising a plurality of taps;
- removing certain taps from the channel estimate;
- if a combined power of taps of the channel estimate after removing certain taps that define a to be measured channel is less than a certain threshold below an amount based on a total power of the signal, discarding the channel estimate for the cell and/or reporting a minimum reportable receive power and/or processing a very small value.
A method comprising:
- without first performing interference cancellation, a mobile device processing a signal to detect a ghost cell, a ghost cell being a cell with an unreliable measurement result as defined by ghost cell detection criteria;
- in case a ghost cell is detected, the mobile device systematically searching for cells and their midamble codes which are not in a neighbor cell list;
- for each cell found as a result of the systematic search, the wireless device applying interference cancellation of a component of the received signal due to the cell if a total received power as defined by a sum of taps of a post processed channel estimate of the cell is large enough as defined by a threshold compared to the overall received power of the midamble.
17-25. (canceled)
31-46. (canceled)
Dependencies are inferred from the claim text.