Generating and transmitting demodulation reference signals

• US 10,708,900 B2
• Filed: 07/25/2018
• Issued: 07/07/2020
• Est. Priority Date: 01/13/2012
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Popovic, Branislav, Sun, Weijun
• Primary Examiner(s): La, Phong
• Application Number:
  US16/044,933
• Publication Number:
  US 20180332571A1
• Time in Patent Office: 713 Days
• Field of Search: 370330
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

The present disclosure provides a solution which solves the problem of demodulation reference signal (DMRS) ambiguity by introducing separate, i.e. different DMRSs. This is especially the case for systems employing dynamic allocation of control and data signals to different PRBs.

Claims

1. An apparatus, comprising:

a receiver configured to receive communication signals;

a memory containing computer instructions for execution by at least one processor; and

at least one processor coupled to retrieve and execute the computer instructions wherein, when executed by the at least one processor, cause the apparatus to;

receive and process at least one first receiver specific demodulation reference signal associated with a data channel having time-frequency resource elements (REs) of a first physical resource block (PRB) that are utilized for transmission of the data channel and the at least one first receiver specific demodulation reference signal, and also having time-frequency REs of the first PRB that are utilized for transmission of the at least one first receiver specific demodulation reference signal located in a first set of RE positions in the first PRB,

receive at least one second receiver specific demodulation reference signal associated with a control channel that is associated with the data channel, the at least one second receiver specific demodulation reference signal being different from the at least one first receiver specific demodulation reference signal, wherein;

time-frequency REs of a second PRB are utilized for transmission of the control channel and the at least one second receiver specific demodulation reference signal,

time-frequency REs of the second PRB being utilized for transmission of the at least one second receiver specific demodulation reference signal located in a second set of RE positions in the second PRB, and

the second set of RE positions in the second PRB overlap with the first set of RE positions in the first PRB, and a first sequence of symbols {a_p(k)}, k=0, 1, . . . , L−

1 is used for modulating time-frequency REs at a first set of RE positions in a first PRB for generation of the at least one first receiver specific demodulation reference signal, the first PRB being used for transmission of the data channel at a transmitting antenna port p, and L is a positive integer; and

demodulate the control channel by using the at least one second receiver specific demodulation reference signal.

2. The apparatus according to claim 1,

wherein the first sequence of symbols {a_p(k)}, k=0, 1, . . . , L−

1 is defined as;

a_p (k)=w_p(k)q(n_PRB k), k=0, 1, . . . , 11, where q(n_PRB, k) is a PRB scrambling sequence.

3. The apparatus according to claim 1, wherein a second sequence of symbols {b_u,p (k)}, k=0, 1, . . . , L−

1 is used for modulating time-frequency resource elements within a second physical resource blocks for generation of the second receiver specific demodulation reference signal, and the second physical resource being used for transmission of the control channel at a transmit antenna port p, L is a positive integer.

4. The apparatus according to claim 3, wherein the second sequence of symbols {b_u,p(k)} being a u-th sequence from a set of U sequences, u and U being positive integers, the set of U sequences being capable of being allocated to one or more receiver nodes in the wireless communication system.

5. The apparatus according to claim 3, wherein the second sequence of symbols {b_u,p(k)}, k=0, 1, . . . , L−

1 is obtained by multiplying a first sequence of symbols {a_p (k)}, k=0, 1, . . . , L−

1 with a receiver specific signature sequence {s_u(k)}, k=0, 1, . . . , L−

1.

6. The apparatus according to claim 1, wherein the at least one first receiver specific demodulation reference signal is modulated in a way different from the way that the at least one second receiver specific demodulation reference signal is modulated.

7. An apparatus, comprising:

transceiver circuitry; and

processing circuitry coupled to the transceiver circuitry,

wherein the apparatus is configured to;

transmit at least one first receiver specific demodulation reference signal associated with a data channel, having time-frequency resource elements (REs) of a first physical resource block (PRB) for transmission of the data channel and the at least one first receiver specific demodulation reference signal, and time-frequency REs of the first PRB being utilized for transmission of the at least one first receiver specific demodulation reference signal located in a first set of RE positions in the first PRB; and

transmit at least one second receiver specific demodulation reference signal associated with a control channel associated with the data channel, the at least one second receiver specific demodulation reference signal is different from the at least one first receiver specific demodulation reference signal, time-frequency REs of a second PRB are utilized for transmission of the control channel and the at least one second receiver specific demodulation reference signal, the time-frequency REs of the second PRB are further utilized for transmission of the at least one second receiver specific demodulation reference signal located in a second set of RE positions in the second PRB, and the second set of RE positions in the second PRB overlap with the first set of RE positions in the first PRB, wherein a first sequence of symbols {a_p (k)}, k=0, 1, . . . , L−

1 is used for modulating time-frequency REs at a first set of RE positions in a first PRB for generation of the at least one first receiver specific demodulation reference signal, the first PRB being used for transmission of the data channel at a transmitting antenna port p, and L is a positive integer.

8. The apparatus according to claim 7, wherein the first sequence of symbols {a_p (k)}, k=0,1, . . . , L−

1 is defined as;

a_p (k)=w_p(k)q(n_PRB, k), k=0, 1, . . . , 11, where q(n_PRB, k) is a PRB scrambling sequence.

9. The apparatus according to claim 7, wherein a second sequence of symbols {b_u,p (k)}, k=0, 1, . . . , L−

1 is used for modulating time-frequency resource elements within a second physical resource blocks for generation of the second receiver specific demodulation reference signal, and the second physical resource being used for transmission of the control channel at a transmit antenna port p, and L is a positive integer.

10. The apparatus according to claim 9, wherein the second sequence of symbols {b_u,p (k)} being a u-th sequence from a set of U sequences, u and U being positive integers, the set of U sequences being capable of being allocated to one or more receiver nodes in the wireless communication system.

11. The apparatus according to claim 9, wherein the second sequence of symbols {b_u,p (k)}, k=0, 1, . . . , L−

1 is obtained by multiplying a first sequence of symbols {a_p (k)}, k=0, 1, . . . , L−

1 with a receiver specific signature sequence {s_u(k)}, k=0, 1, . . . , L−

1.

12. The apparatus according to claim 7, wherein the at least one first receiver specific demodulation reference signal is modulated in a way different from the way that the at least one second receiver specific demodulation reference signal is modulated.

13. The apparatus according to claim 7, wherein the control channel is a physical downlink control channel, and the data channel is a physical downlink shared channel.

14. A communications system, comprising:

a first apparatus, configured to transmit at least one first receiver specific demodulation reference signal associated with a data channel, wherein time-frequency resource elements (Res) of a first physical resource block (PRB) are utilized for transmission of the data channel and the at least one first receiver specific demodulation reference signal, and time-frequency REs of the first PRB being utilized for transmission of the at least one first receiver specific demodulation reference signal located in a first set of RE positions in the first PRB, and to transmit at least one second receiver specific demodulation reference signal associated with a control channel, wherein the control channel is associated with the data channel, the at least one second receiver specific demodulation reference signal is different from the at least one first receiver specific demodulation reference signal, time-frequency REs of a second PRB are utilized for transmission of the control channel and the at least one second receiver specific demodulation reference signal, the time-frequency REs of the second PRB are further utilized for transmission of the at least one second receiver specific demodulation reference signal located in a second set of RE positions in the second PRB, and the second set of RE positions in the second PRB overlap with the first set of RE positions in the first PRB, wherein a first sequence of symbols {a_p (k)}, k=0,1, . . . , L−

1 is used for modulating time-frequency REs at a first set of RE positions in a first PRB for generation of the at least one first receiver specific demodulation reference signal, the first PRB being used for transmission of the data channel at a transmitting antenna port p, and L is a positive integer; and

a second apparatus, configured to receive the at least one first receiver specific demodulation reference signal and the at least one second receiver specific demodulation reference signal, and to demodulate the control channel by using the at least one second receiver specific demodulation reference signal.

15. The system according to claim 14, wherein the first sequence of symbols {a_p (k)}, k=0,1, . . . , L−

1 is defined as;

a_p (k)=w_p(k)q(n_PRB, k), k=0,1, . . . , 11, where q(n_PRB, k) is a PRB scrambling sequence.

16. The system according to claim 14, wherein a second sequence of symbols {b_u,p (k)}, k=0,1, . . . , L−

1 is used for modulating time-frequency resource elements within a second physical resource blocks for generation of the second receiver specific demodulation reference signal, and the second physical resource being used for transmission of the control channel at a transmit antenna port p, and L is a positive integer.

17. The system according to claim 16, wherein the second sequence of symbols {b_u,p (k)} being a u-th sequence from a set of U sequences, u and U being positive integers, the set of U sequences being capable of being allocated to one or more receiver nodes in the system.

18. The system according to claim 16, wherein the second sequence of symbols {b_u,p (k)}, k=0,1, . . . , L−

1 is obtained by multiplying a first sequence of symbols {a_p (k)}, k=0,1, . . . , L−

1 with a receiver specific signature sequence {s_u(k)}, k=0,1, . . . , L−

1.

19. The system according to claim 14, wherein the at least one first receiver specific demodulation reference signal is modulated in a way different from the way that the at least one second receiver specific demodulation reference signal is modulated.

20. The system according to claim 14, wherein the control channel is a physical downlink control channel, and the data channel is a physical downlink shared channel.