Method for allocating multi-UEs' sounding reference signal (SRS) uplink resources and eNB
The present invention is to provide a method for allocating multi-UEs' Sounding Reference Signal (SRS) uplink resources, and an eNB for allocating multi-UEs' SRS uplink resources with the method. The method may automatically and dynamically allocate multi-UEs' SRS resource in both the time domain resource and the frequency domain resource in accordance with system capacity attribute value and configured SRS transmission period. When multi-UEs' SRS are positioned in the same time domain resource and same frequency domain resource, it is also possible to further divide the multi-UEs' SRS automatically by a method of configuring cyclic shift. According to the method of the present invention, the eNB may allocate SRS resources for multi-UEs more flexibly and effectively, which reduces disturbance to multi-UEs' SRS, improves the decoding performance of physical layer, and thus improves the stability of a system.
1. A method, implemented by a base station, of allocating Sounding Reference Signal (SRS) uplink resources to multiple User Equipments (UEs), the method comprising:
inputting a value of an SRS period (T SRS ) of a system, a minimum period (T srs _ mini _ period ) of SRS supported by the system, a maximum number of a UE's SRS (n max _ SRS ) per time domain resource bearable in the minimum period, and a subframe SRS offset (T offset );
configuring a value of a time domain parameter (srs-ConfigIndex) for allocating time domain resources for the UEs' SRS;
configuring a value of a frequency domain parameter (transmissionComb) for mapping the UEs' SRS in same time domain resource to different frequency domain resources;
configuring a value of a cyclic shift parameter (cyclicShift) for further dividing the UEs' SRS in same time domain resource and frequency domain resource;
transmitting the srs-ConfigIndex, transmissionComb, and cyclicShift parameters configured by the base station to the respective UEs.
2. The method of claim 1 , wherein only one time domain resource is usable in the minimum period for being allocated to the UEs' SRS.
3. The method of claim 1 , wherein the configuring the value of the time domain parameter comprises:
determining a number of time domain resources available in the SRS period;
determining a position (P SRS _ Position ) of a time domain resource allocated to each UE's SRS transmission in the SRS period;
configuring a value of the time domain parameter for each of the UEs according to the determined position of the time domain resource.
4. The method of claim 3 , wherein srs-ConfigIndex is configured according to:
( T SRS +5)+ P SRS _ Position *T srs _ mini _ period +T offset ;
wherein T SRS is the value of the SRS period;
P SRS _ Position is a position of a time domain resource in the SRS period allocated to each UE's SRS transmission;
T srs _ mini _ period is the minimum period of SRS supported by the system; and
T offset is the subframe SRS offset.
5. The method of claim 3 , further comprising checking, prior to the configuring the value of the time domain parameter, whether the position of the time domain resource allocated to each of the UEs exceeds a number of time domain resources available in the SRS period.
6. The method of claim 1 , wherein the configuring the value of the frequency domain parameter comprises:
providing an index for each of UEs in the same time domain resource;
configuring the value of the frequency domain parameter for each of the UE's SRS based on the UE's index.
7. The method of claim 6 , wherein the value of the frequency domain parameter is configured according to:
transmissionComb=(I UE _ SRS _ Index −1)% 2
wherein I UE _ SRS _ Index denotes an index of a UE in the time domain resource.
8. The method of claim 1 , wherein the configuring the value of the cyclic shift parameter comprises:
providing an index for each of UEs in the same time domain resource;
configuring the value of the cyclic shift parameter for each of the UE's SRS based on the UE's index.
9. The method of claim 8 , wherein the value of the cyclic shift parameter is configured according to:
cyclicShift=floor(( I UE _ SRS _ Index −1)/2)% 8
wherein I UE _ SRS _ Index denotes an index of a UE in the time domain resource.
10. The method of claim 1 , wherein all of the UEs' SRS are configured to have an identical period.
11. The method of claim 1 , wherein the time domain resources comprise an Uplink Pilot Time Slot in a special subframe, or any normal uplink subframe, based on current uplink and downlink configurations.
12. A base station comprising:
a main control processing circuit configured to:
configure a time domain parameter (srs-ConfigIndex);
configure a frequency domain parameter (transmissionComb);
configure a cyclic shift parameter (cyclicShift); and
allocate Sounding Reference Signal (SRS) resources to multiple User Equipments (UEs);
a downlink processing circuit configured to send the srs-ConfigIndex, transmissionComb, and cyclicShift parameters configured by the main control processing circuit to the respective UEs;
an uplink processing circuit for receiving SRS sent by the respective UEs;
wherein the main control processing circuit inputs an SRS period (T SRS ) of a system, a minimum period (T srs _ mini _ period ) of SRS supported by the system, a maximum number of the UE's SRS (n max _ SRS ) per time domain resource bearable in the minimum period, and a subframe SRS offset (T offset ) and comprises:
a time domain parameter configuring circuit arranged to configure a value of the time domain parameter to allocate time domain resources to the UEs' SRS;
a frequency domain parameter configuring circuit arranged to configure a value of the frequency domain parameter to map UEs' SRS in same time domain resource to different frequency domain resources;
a cyclic shift parameter configuring circuit arranged to configure a value of the cyclic shift parameter for further dividing UEs' SRS in same time domain resource and frequency domain resource.
13. The base station of claim 12 , wherein the time domain parameter configuring circuit is arranged to configure the srs-ConfigIndex according to:
( T SRS +5)+ P SRS _ Position T srs _ mini _ period +T offset ;
wherein T SRS is a value of an SRS period;
P SRS _ Position is a position of a time domain resource in the SRS period allocated to each UE's SRS transmission;
T srs _ mini _ period is a minimum period of SRS supported by the system; and
T offset is a subframe offset of the SRS.
14. The base station of claim 12 , wherein the frequency domain parameter configuring circuit is arranged to configure the value of the frequency domain parameter according to:
transmissionComb=( I UE _ SRS _ index −1)% 2
wherein I UE _ SRS _ Index denotes an index of a UE in the time domain resource.
15. The base station of claim 12 , wherein the cyclic shift parameter configuring circuit is arranged to configure the value of the cyclic shift parameter according to:
cyclicShift=floor(( I UE _ SRS _ Index −1)/2)% 8
wherein I UE _ SRS _ Index denotes an index of a UE in the time domain resource.
16. The base station of claim 12 , wherein the time domain resources comprise an Uplink Pilot Time Slot in a special subframe, or any normal uplink subframe, based on current uplink and downlink configurations.