1. A method for generating and transmitting channel feedback by a transmitter apparatus, said method comprising:
determining at least one first quality value averaged over a long term time interval for a first transmission channel from a first antenna system of a radio communication system to an antenna system of a network node comprising said transmitter apparatus and at least one second quality value averaged over said long term time interval for at least one second transmission channel from at least one second antenna system of said radio communication system to said antenna system of said network node,
determining jointly for said first transmission channel and for said at least one second transmission channel a distribution of radio resource units of a predefined feedback radio resource based on said at least first quality value and said at least second quality value,
transmitting to a receiver apparatus a long term feedback comprising said at least one first quality value and said at least one second quality value, and
transmitting with a short term time interval smaller than or equal to said long term time interval to said receiver apparatus a short term feedback comprising first short term information for said first transmission channel and at least second short term information for said at least second transmission channel using said distribution of radio resource units,
wherein said distribution of radio resource units is determined by a reverse water-filling algorithm and wherein said reverse water-filling algorithm comprises incrementally reducing a water filling level and allocating radio resource units to said at least first quality value and said at least second quality value depending on levels of said at least first quality value and said at least second quality value exceeding said water filling level.
2. Method according to claim 1, wherein said predefined feedback radio resource for said short term feedback is split into a first segment for a repeated transmission of said short term feedback for said first transmission channel and at least one second segment for a repeated transmission of said short term feedback of said at least one second transmission channel depending on said at least first quality value and said at least second quality value.
3. Method according to claim 1, wherein said first short term information relates to at least one first transmission path from one of at least one antenna element of said first antenna system to one of at least one antenna element of said antenna system of said network node and wherein said at least second short term information relates to at least one second transmission path from one of at least one antenna element of said at least one second antenna system to one of said at least one antenna element of said antenna system of said network node.
4. Method according to claim 1, wherein for an orthogonal frequency-division multiplexing transmission via said first transmission channel and said at least second transmission channel said first short term information comprises a first set of coefficients allowing to reconstruct a frequency-domain channel transfer function of said at least one first transmission path and said at least second short term information comprises at least one second set of coefficients allowing to reconstruct a frequency-domain channel transfer function of said at least one second transmission path or wherein for a code division multiple access transmission or a wideband code division multiple access transmission via said first transmission channel and said at least second transmission channel said first short term information comprises a first set of coefficients allowing to reconstruct a frequency-domain channel transfer function or a time-domain channel impulse response of said at least one first transmission path and said at least second short term information comprises at least one second set of coefficients allowing to reconstruct a frequency-domain channel transfer function or a time-domain channel impulse response of said at least one second transmission path.
5. Method according to claim 1, wherein said distribution of radio resource units (DIS-RU) comprises at least one radio resource unit for each transmission channel of a reporting cluster predefined by said receiver apparatus.
6. (canceled)
7. Method according to claim 1, wherein said long term feedback further comprises at least one first time delay value of said at least one first quality value and at least one second time delay value of said at least one second quality value, wherein said at least first quality value is a first power value and wherein said at least second quality value is a second power value.
8. Method according to claim 7, wherein said at least one first time delay value and said at least first power value are determined for at least one first local maximum of a first channel impulse response averaged over first channel impulse responses for first transmission paths of said first transmission channel between one of antenna elements of said first antenna system to one of antenna elements of said antenna system of said network node and wherein said at least second time delay value and said at least second power value are determined for at least one second local maximum of a second channel impulse response averaged over second channel impulse responses for transmission paths of said at least second transmission channel between one of antenna elements of said at least second antenna system to one of said antenna elements of said antenna system of said network node.
9. Method according to claim 8, wherein said determining step for said distribution of radio resource units allocates radio resource units to said at least first local maximum and to said at least second local maximum.
10. Method according to claim 8, wherein said long term feedback is only transmitted for local maxima of said averaged first channel impulse response and of said averaged at least second channel impulse response with an allocated number of radio resource units larger than zero.
11. Method according to claim 1, wherein said transmitting step for said long term feedback is repeated by said long term time interval or repeated, when said distribution of radio resource units has been changed.
12. Method for receiving and retrieving channel feedback at a receiver apparatus, said method comprising:
receiving from a transmitter apparatus a long term feedback comprising at least one first quality value averaged over a long term time interval for a first transmission channel from a first antenna system of a radio communication system to an antenna system of a network node comprising said transmitter apparatus and at least one second quality value averaged over said long term time interval for at least one second transmission channel from at least one second antenna system of said radio communication system to said antenna system of said network node,
receiving from said transmitter apparatus with a short term time interval smaller than or equal to said long term time interval a short term feedback comprising first short term information for said first transmission channel and at least second short term information for said at least second transmission channel using a distribution of radio resource units of a predefined feedback radio resource,
determining jointly for said first transmission channel and for said at least one second transmission channel said distribution of radio resource units based on said at least one first quality value and said at least one second quality value, and
determining said first short term information and said at least second short term information from said short term feedback based on said distribution of radio resource units,
wherein said distribution of radio resource units is determined by a reverse water-filling algorithm and wherein said reverse water-filling algorithm comprises incrementally reducing a water filling level and allocating radio resource units to said at least first quality value and said at least second quality value depending on levels of said at least first quality value and said at least second quality value exceeding said water filling level.
13. (canceled)
14. A transmitter apparatus for generating and transmitting channel feedback, said transmitter apparatus comprising:
means for determining at least one first quality value averaged over a long term time interval for a first transmission channel from a first antenna system of a radio communication system to an antenna system of a network node comprising said transmitter apparatus and at least one second quality value averaged over said long term time interval for at least one second transmission channel from at least one second antenna system of said radio communication system to said antenna system of said network node,
means for determining jointly for said first transmission channel and for said at least one second transmission channel a distribution of radio resource units of a predefined feedback radio resource based on said at least first quality value and said at least second quality value, and
means for transmitting to a receiver apparatus a long term feedback comprising said at least one first quality value and said at least one second quality value and for transmitting with a short term time interval smaller than or equal to said long term time interval to said receiver apparatus a short term feedback comprising first short term information for said first transmission channel and at least second short term information for said at least second transmission channel using said distribution of radio resource units
wherein said means for determining said distribution of radio resource units is configured to determine said distribution of radio resource units by a reverse water-filling algorithm and wherein said reverse water-filling algorithm comprises incrementally reducing a water filling level and allocating radio resource units to said at least first quality value and said at least second quality value depending on levels of said at least first quality value and said at least second quality value exceeding said water filling level.
15. A receiver apparatus for receiving and retrieving a channel feedback, said receiver apparatus comprising:
means for receiving from a transmitter apparatus a long term feedback comprising at least one first quality value averaged over a long term time interval for a first transmission channel from a first antenna system of a radio communication system to an antenna system of a network node comprising said transmitter apparatus and at least one second quality value averaged over said long term time interval for at least one second transmission channel from at least one second antenna system of said radio communication system to said antenna system of said network node and for receiving from said transmitter apparatus with a short term time interval smaller than or equal to said long term time interval a short term feedback comprising first short term information for said first transmission channel and at least second short term information for said at least second transmission channel using a distribution of radio resource units of a predefined feedback radio resource,
means for determining jointly for said first transmission channel and for said at least one second transmission channel said distribution of radio resource units based on said at least one first quality value and said at least one second quality value, and
means for determining said first short term information and said at least second short term information from said short term feedback based on said distribution of radio resource units
wherein said means for determining said distribution of radio resource units is configured to determine said distribution of radio resource units by a reverse water-filling algorithm and wherein said reverse water-filling algorithm comprises incrementally reducing a water filling level and allocating radio resource units to said at least first quality value and said at least second quality value depending on levels of said at least first quality value and said at least second quality value exceeding said water filling level.
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. An activation mechanism of a locking mechanism of a caster comprising:
at least one pedal shaft operatively connected to a locking tab of said locking mechanism, wherein vertical translation of said at least one pedal shaft causes lateral translation of said locking tab.
2. The activation mechanism of claim 1, wherein said at least one pedal shaft is translatable in a reciprocating manner.
3. The activation mechanism of claim 1 further including a connecting rod operatively connected to said at least one pedal shaft and said locking tab.
4. The activation mechanism of claim 3, wherein a first distal end of a clevis connector is attached to a distal end of said connecting rod, and a second distal end of said clevis connector is attached to said locking tab.
5. The activation mechanism of claim 1, wherein said at least one pedal shaft includes a first pedal shaft and a second pedal shaft.
6. The activation mechanism of claim 5, wherein said first pedal shaft and said second pedal shaft translate in an opposing reciprocal manner.
7. The activation mechanism of claim 5, wherein said first pedal shaft and said second pedal shaft have a first rack gear formed thereon.
8. The activation mechanism of claim 7, wherein said connecting rod has a second rack gear formed thereon.
9. The activation mechanism of claim 8, wherein said first rack gear of said first pedal shaft is meshingly engaged with a first transfer gear that is integrally attached to a rotatable first rod, and a second transfer gear being meshingly engaged with said second rack gear formed on said connecting rod is integrally attached to said first rod.
10. The activation mechanism of claim 9, wherein translational displacement of said first pedal shaft is transferred to rotational movement of said first rod by way of said first transfer gear in meshing engagement with said first rack gear of said first pedal shaft, and rotational movement of said first rod is transferred to lateral translation of said connecting rod by way of said second transfer gear in meshing engagement with said second rack gear of said connecting rod.
11. The activation mechanism of claim 9, wherein a third transfer gear is integrally attached to said first rod, and said third transfer gear is in meshing engagement with said first rack gear of said second transfer pedal.
12. The activation mechanism of claim 9, wherein translational displacement of said first pedal shaft is transferred to rotational movement of said first rod, and rotational movement of said first rod is transferred to translational displacement of said second pedal.
13. The activation mechanism of claim 7, wherein translational displacement of said first pedal shaft results in vertical displacement of said second pedal shaft in an opposing direction relative to the direction of translational displacement of said first pedal shaft.
14. The activation mechanism of claim 9, wherein said first pedal shaft is offset relative to said second pedal shaft with respect to a longitudinal axis of said first rod.
15. The activation mechanism of claim 8, wherein said first rack gear of said second pedal shaft is meshingly engaged with a third transfer gear that is integrally connected to a second shaft having a fourth transfer gear integrally attached thereto, and said fourth transfer gear is operatively connected to said connecting rod.
16. The activation mechanism of claim 15, wherein said fourth transfer gear is meshingly engaged with a first idler gear that is integrally attached to a third rod, and a second idler gear that is meshingly engaged with said second rack gear of said connecting rod is integrally attached to said third rod.
17. The activation mechanism of claim 1, wherein said caster is attached to a component cart for a diagnostic ultrasound system.
18. A method for actuating a locking tab of a locking mechanism for a caster, said method comprising:
actuating a first pedal shaft in a substantially vertical direction;
translating a connecting rod in a substantially lateral direction in response to actuation of said first pedal shaft, wherein said connecting rod is operatively connected to said first pedal shaft;
actuating said locking tab in response to lateral displacement of said connecting rod.
19. The method of claim 18, wherein translation of said connecting rod actuates said locking tab between a first locking position, a second locking position, and a third locking position.
20. The method of claim 18, wherein actuation of said first pedal shaft results in a second pedal shaft being actuated in a direction opposite that of said first pedal shaft.
21. An activation mechanism of a locking mechanism for a caster, said activation mechanism comprising:
a first pedal shaft and a second pedal shaft operatively connected to a first rotatable gear, wherein said first pedal shaft and said second pedal shaft are vertically translatable;
a third pedal shaft operatively connected to a second rotatable gear, wherein said third pedal shaft is vertically translatable;
a fourth pedal shaft operatively connected to a third rotatable gear, wherein said fourth pedal shaft is vertically translatable;
a laterally translatable connecting rod operatively connected to said first rotatable gear, said second rotatable gear, and said third rotatable gear; and a clevis connector connecting said connecting rod to a locking tab of said locking mechanism, wherein vertical translation of one of said first pedal shaft, said second pedal shaft, said third pedal shaft, or said fourth pedal shaft results in the lateral translation of said connecting rod and actuation of said locking tab, thereby switching said locking mechanism between at least two locking modes.