BASKARAN DHIVAGAR (IN)
MILLETH JENISTON DEVIRAJ KLUTTO (IN)
RAMAMURTHI BHASKAR (IN)
INDIAN INST TECH MADRAS (IN)
US20210135823A1 | 2021-05-06 | |||
US20110200143A1 | 2011-08-18 |
CLAIMS: 1. A method for communication between a user equipment and a base station, the method comprising: determining Sounding Reference Signal antenna ports of a user equipment (102) configured for transmission of sounding reference signals to a base station (104); dividing the antenna ports into a first group of antenna ports and a second group of antenna ports when a number of antenna ports is greater than a predefined number of antenna ports; determining a first set of parameters associated with the first group of antenna ports and a second set of parameters associated with the second group of antenna ports, for generation and transmission of the sounding reference signals, wherein orthogonality is maintained between the sounding reference signals of the first group of antenna ports and the sounding reference signals of the second group of antenna ports using one of a group index, a cyclic shift, time division multiplexing, and frequency division multiplexing; generating, by the user equipment (102), a first set of sounding reference signals using the first set of parameters and a second set of sounding reference signals using the second set of parameters; and transmitting, by the user equipment (102) to the base station (104), the first set of sounding reference signals over the first group of antenna ports using the first set of parameters and the second set of sounding reference signals over the second group of antenna ports using the second set of parameters. 2. The method as claimed in claim 1, wherein the first set of parameters and the second set of parameters comprise group index, sequence index, cyclic shift of Zadoff-Chu (ZC) sequences, OFDM symbol, slot index, and a transmission comb. 3. The method as claimed in claim 1, wherein the first set of parameters are determined using a first group index and the second set of parameters are determined using a second group index. 4. The method as claimed in claim 3, wherein the second group index is determined by addition of the first group index and a group shift provided by the base station (104). 5. The method as claimed in claim 1, wherein the first set of parameters are determined using a first set of cyclic shifts and the second set of parameters are determined using a second set of cyclic shifts. 6. The method as claimed in claim 5, wherein the second set of cyclic shifts are deter- mined using the first set of cyclic shifts and an offset value of cyclic shift provided by the base station (104). 7. The method as claimed in claim 1, wherein the first set of parameters are determined using a first set of OFDM symbols and the second set of parameters are determined using a second set of OFDM symbols. 8. The method as claimed in claim 1, wherein the first set of parameters are determined using a first time slot and the second set of parameters are determined using a second time slot. 9. The method as claimed in claim 8, wherein the second time slot is determined by addition of the first time slot and a slot offset provided by the base station (104). 10. The method as claimed in claim 1, wherein the first set of parameters are determined using a first transmission comb and the second set of parameters are determined using a second transmission comb. |
AMENDED CLAIMS received by the International Bureau on 25 August 2023 (25.08.2023) CLAIMS: 1. A method for communication between a user equipment and a base station, the method comprising: determining Sounding Reference Signal antenna ports of a user equipment (102) configured for transmission of sounding reference signals to a base station (104); dividing the antenna ports into a first group of antenna ports and a second group of antenna ports when a number of antenna ports is greater than a predefined number of antenna ports; determining a first set of parameters associated with the first group of antenna ports and a second set of parameters associated with the second group of antenna ports, for generation and transmission of the sounding reference signals, wherein orthogonality is maintained between the sounding reference signals of the first group of antenna ports and the sounding reference signals of the second group of antenna ports using one of a group index, a cyclic shift, and time division multiplexing; generating, by the user equipment (102), a first set of sounding reference signals using the first set of parameters and a second set of sounding reference signals using the second set of parameters; and transmitting, by the user equipment (102) to the base station (104), the first set of sounding reference signals over the first group of antenna ports using the first set of parameters and the second set of sounding reference signals over the second group of antenna ports using the second set of parameters. 2. The method as claimed in claim 1, wherein the first set of parameters and the second set of parameters comprise group index, sequence index, cyclic shift of Zadoff-Chu (ZC) sequences, OFDM symbol and slot index. 3. The method as claimed in claim 1, wherein the first set of parameters are determined using a first group index and the second set of parameters are determined using a second group index. 4. The method as claimed in claim 3, wherein the second group index is determined by addition of the first group index and a group shift provided by the base station (104). 5. The method as claimed in claim 1, wherein the first set of parameters are determined using a first set of cyclic shifts and the second set of parameters are determined using a second set of cyclic shifts. 6. The method as claimed in claim 5, wherein the second set of cyclic shifts are deter- mined using the first set of cyclic shifts and an offset value of cyclic shift provided by the base station (104). 7. The method as claimed in claim 1, wherein the first set of parameters are determined using a first set of OFDM symbols and the second set of parameters are determined using a second set of OFDM symbols. 8. The method as claimed in claim 1, wherein the first set of parameters are determined using a first time slot and the second set of parameters are determined using a second time slot. 9. The method as claimed in claim 8, wherein the second time slot is determined by addition of the first time slot and a slot offset provided by the base station (104). |
[0040] The ZC sequence may be mapped to physical resources for transmission of the SRS to the BS 104, at step 310. Thus, the UE 102 may maintain orthogonality between the first set of antenna ports and the second set of antenna ports by using different cyclic shift. [0041] Fig.4 illustrates a flow chart of a second method for transmission of SRS to the BS 102 using a cyclic shift, in accordance with an embodiment of the present invention. The UE 102 may determine a common group index ( u ) of the ZC sequence for the first group of antenna ports and the second group of antenna ports based on slot and symbol index, at step 402. The common group index ( u ) is calculated using equation (5) as described above. [0042] The UE 102 may determine cyclic shifts of the ZC sequence for the first group of antenna ports and the second group of antenna ports, at step 404. The cyclic shifts may be equally spaced or uniformly distributed. The cyclic shifts are calculated using equations (13), (14), (15), and (16), WhereCS shift is configured for the UE 102 by the BS 104 using higher layer signaling. CS shift ∈ {1,2}, for example, if = 12,CS shift = 1 if = 8. IfCS shift is not configured by the BS 104, the UE 102 assumes a default value. [0043] The ZC sequence may be mapped to physical resources for transmission of SRS to the BS 104, at step 406. Thus, the UE 102 may maintain orthogonality between the first set of antenna ports and the second set of antenna ports by using different cyclic shift. [0044] Fig.5 illustrates a flow chart of a method for transmission of SRS to the BS 104 using symbols, in accordance with an embodiment of the present invention. The UE 102 may transmit the first group of antenna ports and the second group of antenna ports using Time Division Multiplexing (TDM) in different Orthogonal Frequency-Division Multiplexing (OFDM) symbols. The UE 102 may determine a common group index ( u ) of the ZC sequence for the first group of antenna ports and the second group of antenna ports based on slot and symbol index, at step 502. The common group index ( u ) is calculated using equation (5) as described above. [0045] The UE 102 may check whether an antenna port belongs to the first group of antenna ports or not, at step 504. The UE 102 may determine a first cyclic shift of the ZC sequence for each antenna port of the first group of antenna ports, at step 506. The cyclic shift is calculated using equations (7) and (8) as described above. [0046] The UE 102 may determine a second cyclic shift for each antenna port of the second group of antenna ports, at step 508. The cyclic shift is calculated using equations (9) and (10) as described above. [0047] The UE 102 may obtain details about total number of symbols configured for transmission of SRS to the BS 104. In one implementation, the details about total number of symbols configured for transmission of SRS may be provided by the BS 104 through higher layer signaling, such as RRC. The UE 102 may divide the total number of symbols into a first set of symbols and a second set of symbols. In one implementation, the first set of symbols may be selected from alternate symbols from the total number of symbols, such as {0, 2, 4, .. , 2 ∗ ( − 1)} and the second set of symbols may be selected from remaining symbols from the total number of symbols. In another implementation, the first set of symbols may be selected from consecutive symbols from the total number of symbols, such as {0,1, .. , − 1} and the second set of symbols may be selected from remaining symbols from the total number of symbols. [0048] The UE 102 may map the ZC sequences for the first group of antenna ports with the first set of symbols, at step 510. The ZC sequences are mapped to the first group of antenna ports using equations (17-20), where l' in the equation (17) takes all possible values from the first set of symbols. The frequency-domain starting position is defined by where [0049] Similarly, the UE 102 may map the ZC sequence for the second group of antenna ports with the second set of symbols, at step 512. The ZC sequences are mapped to the second group of antenna ports using equations (21-24), where l' in the equation (21) may be assigned as possible values from the second set of symbols. The frequency-domain starting position is defined by where [0050] Fig.6 illustrates a flow chart of a method for transmission of SRS to the BS 104 using time slots, in accordance with an embodiment of the present invention. The UE 102 may transmit the first group of antenna ports and the second group of antenna ports using TDM in different time slots. The UE 102 may determine a common group index ( u ) of the ZC sequence for the first group of antenna ports and the second group of antenna ports based on slot and symbol index, at step 602. The common group index ( u ) is calculated using equation (5) as described above. [0051] The UE 102 may check whether an antenna port belongs to the first group of antenna ports or not, at step 604. The UE 102 may determine a first cyclic shift of the ZC sequence for each antenna port of the first group of antenna ports, at step 606. The cyclic shift is calculated using equations (7) and (8) as described above. [0052] The UE 102 may determine a second cyclic shift for each antenna port of the second group of antenna ports, at step 608. The cyclic shift is calculated using equations (9) and (10) as described above. [0053] The UE 102 may obtain details about time slots (n) configured for transmission of SRS to the BS 104. In one implementation, the details about time slots (n) configured for transmission of SRS may be provided by the BS 104 through higher layer signaling, such as RRC. The UE 102 may configure to transmit the SRS through the first group of antenna ports in time slot (n). Further, the UE 102 may configure to transmit the SRS through the second group of antenna ports in time slot (n+k). Where k is a slot offset determined using one of a pre-configured value at the UE 102 using the higher layer signaling, as a next SRS transmission occasion, as a next uplink slot, and as a predefined value. [0054] The UE 102 may map the ZC sequences for the first group of antenna ports with the time slot (n), at step 610. The ZC sequences are mapped to the first group of antenna ports using equations (17-20) as described above. [0055] Similarly, the UE 102 may map the ZC sequences for the second group of antenna ports with the time slot (n), at step 612. The ZC sequences are mapped to the second group of antenna ports using equations (21-24) as described above. [0056] Fig.7 illustrates a flow chart of a method for transmission of SRS to the BS 104 using Frequency Division Multiplexing (FDM), in accordance with an embodiment of the present invention. The UE 102 may transmit the first group of antenna ports and the second group of antenna ports using FDM in different frequency domain resources. The UE 102 may determine a common group index ( u ) of the ZC sequence for the first group of antenna ports and the second group of antenna ports based on slot and symbol index, at step 602. The common group index ( u ) is calculated using equation (5) as described above. [0057] The UE 102 may check whether an antenna port belongs to the first group of antenna ports or not, at step 704. The UE 102 may determine a first cyclic shift of the ZC sequence for each antenna port of the first group of antenna ports, at step 706. The cyclic shift is calculated using equations (7) and (8) as described above. [0058] The UE 102 may determine a second cyclic shift for each antenna port of the second group of antenna ports, at step 708. The cyclic shift is calculated using equations (9) and (10) as described above. [0059] The UE 102 may map the ZC sequences for the first group of antenna ports, at step 710. The ZC sequences are mapped to the first group of antenna ports using equations (25-28), where l' in the equation (25) takes all possible values from the set {0,1, .. , − 1} in the slot n . The frequency-domain starting position is defined by equation (26), [0060] Similarly, the UE 102 may map the ZC sequences for the second group of antenna ports, at step 712. The ZC sequences are mapped to the second group of antenna ports using equations (29- …), where l' in the above equation takes all possible values from the set {0,1, .. , − 1} in the slot n + k . where [0061] In the above detailed description, reference is made to the accompanying draw- ings that form a part thereof, and illustrate the best mode presently contemplated for carrying out the invention. However, such description should not be considered as any limitation of scope of the present invention. The structure thus conceived in the present description is susceptible of numerous modifications and variations, all the details may furthermore be replaced with elements having technical equivalence.