1. A method of link adaptation in a mobile radiocommunication system, said method comprising:
calculating a first average of radio measurement results representing radio conditions over a relatively short period, or
calculating a second average of radio measurement results representing radio conditions over a relatively longer period, and
selecting a coding andor modulation scheme based on said first or second average, wherein a more rugged coding andor modulation scheme is selected based on said first average if radio conditions are degrading rapidly, or a more rugged coding andor modulation scheme is selected based on said second average if radio conditions are not degrading rapidly, otherwise a less rugged coding andor modulation scheme is selected based on said second average.
2. The method claimed in claim 1, wherein said selection is based on a first threshold value for determining if radio conditions have degraded rapidly and a second threshold value for determining if radio conditions have not degraded rapidly, said second threshold value being relatively higher or relatively lower than said first threshold value according to whether the value of said radio measurements increases or decreases when radio conditions are degraded.
3. The method claimed in claim 1 wherein said radio measurements include raw BER measurements.
4. The method claimed in claim 1 wherein said radio measurements include SIR measurements.
5. The method claimed in claim 1 wherein, if one of said coding schemes has a coding rate equal to 1, said radio measurements for selecting a more rugged coding scheme from said coding scheme having a coding rate equal to 1 include measurements other than raw BER measurements and said radio measurements for selecting said coding scheme having a code rate equal to 1 from a more rugged coding scheme include raw BER measurements and measurements other than raw BER measurements.
6. The method claimed in claim 5 wherein said radio measurements other than raw BER measurements include SIR measurements.
7. The method claimed in claim 5 wherein said radio measurements other than raw BER measurements include received signal power level measurements.
8. The method claimed in claim 1 wherein, when transmission resumes on said link to which said link adaptation is applied following an interruption of transmission, and if said measurements have not been effected during said interruption of transmission, said coding andor modulation scheme that was being used before said interruption of transmission is used if said period of interruption is relatively short or a default coding andor modulation scheme is used otherwise.
9. The method claimed in claim 8 wherein said default coding andor modulation scheme is the most rugged coding andor modulation scheme.
10. The method claimed in claim 1 wherein said average is obtained by means of an exponential filter defined by a forget factor parameter that is expressed directly as a function of the time period between two measurements or an approximation thereof.
11. The method claimed in claim 10, wherein said filter is defined by the following equations:
yn+1=\u03b1\u0394tnyn+1
AV_M
n
+
1
=
(
1
–
1
y
n
+
1
)
\u2062
AV_M
n
+
1
y
n
+
1
\u2062
m
n
+
1
in which:
AV_Mn+1 is the value of AV_M after an (n+1)th measurement mn+1,
\u0394tn designates the time interval between the nth measurement and the (n+1)th measurement, or an approximation of that time interval, and
\u03b1 is a parameter defining the filter.
12. A mobile radiocommunication network entity comprising means for implementing a link adaptation which comprises:
means for selecting a coding andor modulation scheme as a function of radio conditions represented by an average of radio measurement results;
means for calculating an average over a relatively short period, wherein the average over a relatively short period is used for rapidly selecting a more rugged coding andor modulation scheme if radio conditions are degraded rapidly; and
means for calculating an average over a relatively longer period, wherein the average over a relatively longer period is used for selecting a less rugged coding andor modulation scheme, or a more rugged coding andor modulation scheme if radio conditions are not rapidly degraded.
13. The entity claimed in claim 12 wherein said link adaptation is applied to an up link.
14. The entity claimed in claim 12 wherein said link adaptation is applied to a downlink.
15. A mobile station comprising means for implementing a link adaptation which comprises:
means for selecting a coding andor modulation scheme as a function of radio conditions represented by an average of radio measurement results;
means for calculating an average over a relatively short period, wherein the average over a relatively short period is used for rapidly selecting a more rugged coding andor modulation scheme if radio conditions are degraded rapidly; and
means for calculating an average over a relatively longer period, wherein the average over a relatively longer period is used for selecting a less rugged coding andor modulation scheme, or a more rugged coding andor modulation scheme if radio conditions are not rapidly degraded.
16. The mobile station claimed in claim 15 wherein said link adaptation method is applied to a downlink.
17. The mobile station claimed in claim 15 wherein said link adaptation method is applied to an uplink.
18. A method of link adaptation in a mobile radiocommunication system, said method comprising:
calculating a first average over a first period of time,
calculating a second average over a second period of time longer than said first period of time, and
selecting a coding andor modulation scheme based on said first or second average, wherein a more rugged coding andor modulation scheme is selected based on said first average if a predetermined condition is met, or a more rugged coding andor modulation scheme is selected based on said second average if the predetermined condition is not met, otherwise a less rugged coding andor modulation scheme is selected based on said second average.
19. The method claimed in claim 18 wherein said predetermined condition is that said radio conditions are degrading rapidly.
20. The method claimed in claim 18, wherein said predetermined condition is that said first average is less than said second average by more than a predetermined amount.
21. The method claimed in claim 18, wherein said method changes from using said first average to using said second average when said first average is worse than said second average by a first predetermined amount, and said method changes from using said second average to using said first average when said first average is worse than said second average by a second predetermined amount less than said first predetermined amount.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A keyboard musical instrument comprising:
a tone generator generating tones, and having self-weight; and
plural keys including respective end portions of bars connected to said tone generator so that said self-weight is exerted thereon and other end portions located at opposite sides to said end portions with respect to respective fulcrums of said bars and weighted with resiliently deformed balancers for canceling part of said self-weight, and selectively depressed by a player for specifying the pitch of said tones,
wherein each of said plural keys is formed with at least one hole different in cross section from associated one of said resiliently deformed balancers so as to permit said associated one of said resiliently deformed balancers to exert resilient force on part of the inner surface defining said at least one hole in a direction parallel to a longitudinal direction of associated one of said bars, and
wherein a cross section of each of said deformed balancers has a major line segment longer than a maximum line segment on a cross section of said at least one hole and a minor line segment shorter than said maximum line segment when said balance is outside of said at least one hole so that said major line segment is shrunk in said at least one hole.
2. The keyboard musical instrument as set forth in claim 1, wherein said at least one hole and said associated one of said resiliently deformed balancers have a circular cross section and an elliptic column shape, respectively, and an inner diameter of said circular cross section, a minor axis of said elliptic column and a major axis of said elliptic column correspond to said maximum line segment, said minor line segment and said major line segment, respectively.
3. The keyboard musical instrument as set forth in claim 2, wherein said major axis is substantially in parallel to a longitudinal direction of said associated one of said bars of wood, and said wood has grains extending in parallel to said longitudinal direction.
4. The keyboard musical instrument as set forth in claim 1, wherein said at least one hole and said associated one of said resiliently deformed balancers have a circular cross section and a column shape equivalent to an elliptic cylinder partially cut away at both ends of a minor axis in parallel to a major axis, and an inner diameter of said circular cross section, a line segment between the cut-away surfaces of said elliptic cylinder and said major axis correspond to said maximum line segment, said minor line segment and said major line segment, respectively.
5. The keyboard musical instrument as set forth in claim 1, wherein said associated one of said resiliently deformed balancers has at least peripheral portion made of metal powder containing synthetic resin.