Method and apparatus to reduce multipath effects on radio link control measurements
First Claim
1. A method of processing radio link control measurements for controlling a radio link in a wireless communication network, the method comprising:
- determining successive measurement values for a control parameter of the radio link;
passing the measurement values through a filter circuit comprising an N-point median filter to obtain filtered control values, where N is an integer number; and
controlling the radio link based on the filtered control values.
4 Assignments
0 Petitions
Accused Products
Abstract
One or more median filter circuits are used to filter radio link control measurements corresponding to one or more radio link parameters of interest, such as received signal quality or round trip delay measurements, such as might be used by a base station to trigger mobile station handoff. As such measurements are particularly susceptible to measurement outliers arising from rapid but short-lived changes in radio link propagation paths, for example, the application of median filtering to such measurements is particularly advantageous. That is, by operation of median filtering, which is a non-linear filtering process, outliers in a stream of control measurements, such as are caused by instantaneous changes in channel fading or other propagation phenomena, are discarded rather than averaged in with the other measurements. Non-linear filtering as implemented by exemplary median filtering does not impair or otherwise limit the bandwidth of the underlying control measurements.
-
Citations
44 Claims
-
1. A method of processing radio link control measurements for controlling a radio link in a wireless communication network, the method comprising:
-
determining successive measurement values for a control parameter of the radio link;
passing the measurement values through a filter circuit comprising an N-point median filter to obtain filtered control values, where N is an integer number; and
controlling the radio link based on the filtered control values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. A method of reducing multipath effects on radio link control measurements comprising:
-
determining control measurements based on periodically measuring one or more parameters of a radio link communicatively coupling a mobile station to a base station in a wireless communication network;
time qualifying divergent control measurements by passing the control measurements through a filter that comprises an N-point median filter to thereby obtain filtered control measurements based on median sample outputs from the N-point median filter; and
controlling the radio link based on the filtered control measurements such that non-persistent divergent control measurements caused by multipath effects effectively are ignored. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
-
-
32. A base station for use in a wireless communication network comprising:
one or more processing circuits configured to determine successive measurement values for a control parameter of a radio link communicatively coupling the base station to a remote mobile station, obtain filtered control values by passing the measurement values through an N-point median filter, where N is an integer number, and control the radio link responsive to evaluation of the filtered control values. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
Specification