Method and arrangement for timing the diversity weight changes in a cellular radio system

Abstract

A method and an arrangement are provided for timing a change of diversity weights in a radio connection between a base station and a terminal. A response timing mode is selected from a number of predefined response timing modes. The terminal is informed about the selected response timing mode. An initiation is received from the terminal and it is responded to the initiation by changing certain diversity weights so that the exact moment of time for effecting the change is determined by the selected response timing mode.

1. A method for timing a change of diversity weights in a radio connection between a base station and a terminal, comprisingthe steps of :
 selecting a response timing mode from a number of predefined response timing modes,  
 informing the terminal about the selected response timing mode,  
 receiving an initiation from the terminal, and  
 responding to said initiation by changing certain diversity weights so that the exact moment of time for effecting the change is determined by said selected response timing mode.  
 
     
     
       2. A method according to  claim 1 , wherein the step of  selecting a response timing mode comprisesthe substeps of :
 measuring a propagation delay between the base station and the terminal and  
 mapping the measured propagation delay into a certain response timing mode.  
 
     
     
       3. A method according to  claim 1 , wherein the step of  selecting a response timing mode comprises the substep of  selecting a response timing mode based on the cell size of the base station. 
     
     
       4. A method according to  claim 1 , wherein the step of  selecting a response timing mode comprises the substep of  selecting a response timing mode based on the processing capacity of the base station. 
     
     
       5. A method according to  claim 1 , wherein the steps of  receiving an initiation from the terminal and responding to said initiation by changing certain diversity weights comprise the substeps of comprises:
 receiving said initiation from the terminal in a certain j:th time slot and  
 effecting the change of diversity weigths  weights in either the j+ 1 )  (j+ 1 ) mod M:th time slot or the (j+2) mod M:th time slot depending on which of of  two predefined response timing modes has been selected, where M is the length of the cycle in a cyclic numbering scheme of time slots.  
 
     
     
       6. An arrangement for timing a change of diversity weights in a radio connection between a base station and a terminal, comprising:
 means for selecting a response timing mode from a number of predefined response timing modes,  
 means for informing the terminal about the selected response timing mode,  
 means for receiving an initiation from the terminal and  
 means for responding to said initiation by changing certain diversity weights so that the exact moment of time for effecting the change is determined by said selected response timing mode.  
 
     
     
       7. An apparatus comprising:
 a first communicator section configured to transmit at least one feedback bit for causing a change in one or more antenna weights; and    a second communicator section configured to receive an indication of a response timing mode wherein, the response timing mode indicates at which point of a downlink transmission stream the change in the one or more antenna weights is effected.   
     
     
       8. The apparatus of  claim 7 , wherein the first communicator section is further configured to transmit the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       9. The apparatus of  claim 7 , wherein the first communicator section is further configured to transmit the at least one feedback bit in a feedback information field of an uplink dedicated physical control channel slot. 
     
     
       10. The apparatus of  claim 9 , wherein the first communicator section is further configured to transmit a D bit in the feedback information field of the uplink dedicated physical control channel slot. 
     
     
       11. An apparatus comprising:
 a first communicator section configured to transmit at least one feedback bit in a feedback information field of an uplink dedicated control channel slot, wherein the at least one feedback bit causes a change in one or more antenna weights; and    a second communicator section configured to receive an indication of a response timing mode, wherein the response timing mode indicates a point in time when the change in the one or more antenna weights is effected.   
     
     
       12. The apparatus of  claim 11 , wherein the response timing mode indicates in which of at least one pilot field of a downlink dedicated physical control channel slot the change in the one or more antenna weights is effected. 
     
     
       13. The apparatus of  claim 11 , wherein the first communicator section is further configured to transmit the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       14. An apparatus comprising:
 a downlink signaling analyzer configured to detect a response timing mode; and    a channel estimation unit configured to receive an indication of the detected response timing mode from the downlink signaling analyzer and to determine a moment in time when a change in one or more antenna weights is effected based at least in part on the detected response timing mode.   
     
     
       15. The apparatus of  claim 14 , further comprising:
 a signaling messages composition unit in communication with the channel estimation unit, the signaling messages composition unit being configured to transmit at least one feedback bit for causing the change in the one or more antenna weights.   
     
     
       16. The apparatus of  claim 15 , wherein the signaling messages composition unit is further configured to transmit the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the detected response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       17. The apparatus of  claim 15 , wherein the signaling messages composition unit is further configured to transmit the at least one feedback bit in a feedback information field of an uplink dedicated physical control channel slot. 
     
     
       18. The apparatus of  claim 17 , wherein the signaling messages composition unit is further configured to transmit a D bit in the feedback information field of the uplink dedicated physical control channel slot. 
     
     
       19. An apparatus comprising:
 a detection unit configured to detect a response timing mode; and    a determining unit configured to determine a moment in time when a change in one or more antenna weights is effected based at least in part on the detected response timing mode.   
     
     
       20. The apparatus of  claim 19 , wherein the apparatus further comprises a communicator section configured to transmit at least one feedback bit for causing the change in the one or more antenna weights. 
     
     
       21. The apparatus of  claim 20 , wherein the communicator section is further configured to transmit the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the detected response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       22. The apparatus of  claim 20 , wherein the communicator section is further configured to transmit the at least one feedback bit in a feedback information field of an uplink dedicated physical control channel slot. 
     
     
       23. The apparatus of  claim 22 , wherein the communicator section is further configured to transmit a D bit in the feedback information field of the uplink dedicated physical control channel slot. 
     
     
       24. A network element comprising:
 a user equipment device configured to transmit at least one feedback bit for causing a change in one or more antenna weights and to receive an indication of a response timing mode;    wherein, the response timing mode indicates at which point of a downlink transmission stream the change in the one or more antenna weights is effected.   
     
     
       25. The network element of  claim 24 , wherein the user equipment device is further configured to transmit the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       26. The network element of  claim 24 , wherein the user equipment device is further configured to transmit the at least one feedback bit in a feedback information field of an uplink dedicated physical control channel slot. 
     
     
       27. The network element of  claim 26 , wherein the user equipment device is further configured to transmit a D bit in the feedback information field of the uplink dedicated physical control channel slot. 
     
     
       28. A network element comprising:
 a user equipment device configured to transmit at least one feedback bit in a feedback information field of an uplink dedicated control channel slot, wherein the at least one feedback bit causes a change in one or more antenna weights, the user equipment device also configured to receive an indication of a response timing mode, wherein the response timing mode indicates a point in time when the change in the one or more antenna weights is effected.   
     
     
       29. The network element of  claim 28 , wherein the response timing mode indicates in which of at least one pilot field of a downlink dedicated physical control channel slot the change in the one or more antenna weights is effected. 
     
     
       30. The network element of  claim 28 , wherein the user equipment device is configured to transmit the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       31. A network element comprising:
 a user equipment device configured to detect a response timing mode and to determine a moment in time when a change in one or more antenna weights is effected based at least in part on the detected response timing mode.   
     
     
       32. The network element of  claim 31 , wherein the user equipment device is further configured to transmit at least one feedback bit for causing the change in the one or more antenna weights. 
     
     
       33. The network element of  claim 32 , wherein the user equipment device is further configured to transmit the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the detected response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       34. The network element of  claim 32 , wherein the user equipment device is further configured to transmit the at least one feedback bit in a feedback information field of an uplink dedicated physical control channel slot. 
     
     
       35. The network element of  claim 32 , wherein the user equipment device is further configured to transmit a D bit in the feedback information field of the uplink dedicated physical control channel slot. 
     
     
       36. The apparatus of  claim 24 , wherein the apparatus comprises a network element. 
     
     
       37. The apparatus of  claim 28 , wherein the apparatus comprises a network element. 
     
     
       38. The apparatus of  claim 31 , wherein the apparatus comprises a network element. 
     
     
       39. A method comprising:
 transmitting at least one feedback bit for causing a change in one or more antenna weights; and    receiving an indication of a response timing mode, wherein the response timing mode indicates at which point of a downlink transmission stream the change in the one or more antenna weights is effected.   
     
     
       40. The method of  claim 39  further comprising transmitting the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       41. The method of  claim 39 , further comprising transmitting the at least one feedback bit in a feedback information field of an uplink dedicated physical control channel slot. 
     
     
       42. The method of  claim 41 , further comprising transmitting a D bit in the feedback information field of the uplink dedicated physical control channel slot. 
     
     
       43. A method comprising:
 transmitting at least one feedback bit in a feedback information field of an uplink dedicated control channel slot, wherein the at least one feedback bit causes a change in one or more antenna weights; and    receiving an indication of a response timing mode, wherein the response timing mode indicates a point in time when the change in the one or more antenna weights is effected.   
     
     
       44. The method of  claim 43  wherein the response timing mode indicates in which of at least one pilot field of a downlink dedicated physical control channel slot the change in the one or more antenna weights is effected. 
     
     
       45. The method of  claim 43  further comprising transmitting the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:thj downlink time slot. 
     
     
       46. A method comprising:
 detecting a response timing mode; and    determining a moment in time when a change in one or more antenna weights is effected based at least in part on the detected response timing mode.   
     
     
       47. The method of  claim 46  further comprising transmitting at least one feedback bit for causing the change in the one or mre antenna weights. 
     
     
       48. The method of  claim 47  further comprising transmitting the at least one feedback bit so that the at least one feedback bit is received in a j:th uplink time slot, and wherein the detected response timing mode indicates that the change in the one or more antenna weights is effected in a (j+k) mod C:th downlink time slot. 
     
     
       49. The method of  claim 47  further comprising transmitting the at least one feedback bit in a feedback information field of an uplink dedicated physical control channel slot. 
     
     
       50. The method of  claim 49  further comprising transmitting a D bit in the feedback information field of the uplink dedicated physical control channel slot. 
     
     
       51. An apparatus comprising:
 a response timing mode selection unit for selecting a response timing mode from a number of predefined response timing modes;    a message signaling unit configured to transmit information about the selected response timing mode;    a propagation delay unit configured to detect a request to change diversity weights in a radio connection; and    an antenna weight setting unit for responding to the request by changing certain diversity weights so that the exact moment of time for effecting the change is determined by the selected response timing mode.   
     
     
       52. The apparatus of  claim 51  wherein the response timing mode selection unit is further configured to measure a propagation delay between a base station and a terminal, and map the measured propagation delay into a certain response timing mode. 
     
     
       53. The apparatus of  claim 51  wherein the response timing mode selection unit is further configured to select a response timing mode based on the cell size of a base station. 
     
     
       54. The apparatus of  claim 51  wherein the response timing mode selection unit is further configured to select a response timing mode based on the processing capacity of a base station. 
     
     
       55. The apparatus of  claim 51  wherein the apparatus is further confugred to:
 detect the request in a certain j:th time slot; and    effect the change of diversity weights in either the (j+ 1 ) mod M:th time slot or the (j+ 2 ) mod M:th time slot depending on which of two predefined response timing modes has been selected, where M is the length of the cycle in a cyclic numbering scheme of time slots.