Symbol and Subframe Alignment in a Frame Structure of a Wireless Communication System

• US 20190386862A1
• Filed: 12/21/2018
• Published: 12/19/2019
• Est. Priority Date: 08/04/2016
• 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: Islam, Toufiqul, Au, Kelvin Kar Kin, Ma, Jianglei, Zhang, Liqing, Tang, Zhenfei
• Granted Patent: US 10,728,072 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 27/26025 Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking allocating sub-channels of the transmission path H04L5/003
• CPC Class Codes: H04L 27/2607 Cyclic extensions
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

The time-frequency resources of a particular numerology may be used to transmit OFDM symbols that have a cyclic prefix that is longer than the cyclic prefix of other OFDM symbols. This may complicate alignment across different numerologies. Time-frequency resource partitions are disclosed herein that may assist in symbol alignment and/or subframe alignment across the different numerologies.

Claims

1. A method for transmitting data in a wireless communication system, the method comprising:

transmitting k consecutive orthogonal frequency division multiplexing (OFDM) symbols having a first subcarrier spacing, a first OFDM symbol of the k consecutive OFDM symbols having a time duration t₁, and the remaining OFDM symbols of the k consecutive OFDM symbols each having a time duration t₂<

t₁, a total time duration of the k consecutive OFDM symbols being 0.5 ms; and

transmitting n>

k consecutive OFDM symbols having a second subcarrier spacing greater than the first subcarrier spacing, a first OFDM symbol of then consecutive OFDM symbols having a time duration t₃, and the remaining OFDM symbols of the n consecutive OFDM symbols each having a time duration t₄<

t₃, a total time duration of then consecutive OFDM symbols being 0.5 ms.

2. The method of claim 1, wherein the n consecutive OFDM symbols are transmitted concurrently with the k consecutive OFDM symbols.

3. The method of claim 1, wherein the k consecutive OFDM symbols are transmitted over a first set of subcarriers at the first subcarrier spacing, and wherein the n consecutive OFDM symbols are transmitted over a second set of subcarriers at the second subcarrier spacing.

4. The method of claim 3, wherein the first set of subcarriers and the second set of subcarriers belong to different carriers.

5. The method of claim 3, wherein the first set of subcarriers and the second set of subcarriers belong to a same carrier.

6. The method of claim 1, wherein the first subcarrier spacing is 15 kHz and the second subcarrier spacing is 30 kHz.

7. The method of claim 1, wherein the first subcarrier spacing is 30 kHz and the second subcarrier spacing is 60 kHz.

8. The method of claim 1, wherein the n consecutive OFDM symbols are transmitted concurrently with the k consecutive OFDM symbols, and t₃−

t₄=t₁−

t₂ and t₄<

t₂.

9. The method of claim 1, wherein the n consecutive OFDM symbols are transmitted concurrently with the k consecutive OFDM symbols, and n is an integer multiple of k.

10. The method of claim 9, wherein k=7 and n=14.

11. The method of claim 1, wherein:

the first OFDM symbol of the k consecutive OFDM symbols has a cyclic prefix that is longer than a cyclic prefix of each one of the remaining OFDM symbols of the k consecutive OFDM symbols; and

the first OFDM symbol of then consecutive OFDM symbols has a cyclic prefix that is longer than a cyclic prefix of each one of the remaining OFDM symbols of the n consecutive OFDM symbols.

12. The method of claim 1, wherein a trailing edge of the first OFDM symbol of the k consecutive OFDM symbols is aligned with a trailing edge of the second OFDM symbol of the n consecutive OFDM symbols.

13. The method of claim 1, wherein the second subcarrier spacing is an integer multiple of the first subcarrier spacing.

14. The method of claim 13, wherein the integer multiple is a power of two.

15. The method of claim 1, wherein the first subcarrier spacing is 15 kHz×

2ⁱ, where i is an integer and i≥

0, and wherein the second subcarrier spacing is 15 kHz×

2^j, where j is an integer and j>

i.

16. The method of claim 1, wherein the method is performed by a base station.

17. A transmitter comprising:

a non-transitory memory storage comprising instructions; and

one or more processors in communication with the non-transitory memory storage, wherein the one or more processors execute the instructions to;

transmit k consecutive orthogonal frequency division multiplexing (OFDM) symbols having a first subcarrier spacing, a first OFDM symbol of the k consecutive OFDM symbols having a time duration t₁, and the remaining OFDM symbols of the k consecutive OFDM symbols each having a time duration t₂<

t₁, a total time duration of the k consecutive OFDM symbols being 0.5 ms; and

transmit n>

k consecutive OFDM symbols having a second subcarrier spacing greater than the first subcarrier spacing, a first OFDM symbol of then consecutive OFDM symbols having a time duration t₃, and the remaining OFDM symbols of the n consecutive OFDM symbols each having a time duration t₄<

t₃, a total time duration of then consecutive OFDM symbols being 0.5 ms.

18. The transmitter of claim 17, wherein the one or more processors execute the instructions to transmit the n consecutive OFDM symbols concurrently with the k consecutive OFDM symbols.

19. The transmitter of claim 17, wherein the one or more processors execute the instructions to transmit the k consecutive OFDM symbols over a first set of subcarriers at the first subcarrier spacing, and transmit the n consecutive OFDM symbols over a second set of subcarriers at the second subcarrier spacing.

20. The transmitter of claim 19, wherein the first set of subcarriers and the second set of subcarriers belong to different carriers.

21. The transmitter of claim 19, wherein the first set of subcarriers and the second set of subcarriers belong to a same carrier.

22. The transmitter of claim 17, wherein the first subcarrier spacing is 15 kHz and the second subcarrier spacing is 30 kHz.

23. The transmitter of claim 17, wherein the first subcarrier spacing is 30 kHz and the second subcarrier spacing is 60 kHz.

24. The transmitter of claim 17, wherein the n consecutive OFDM symbols are transmitted concurrently with the k consecutive OFDM symbols, and t₃−

t₄=t₁−

t₂ and t₄<

t₂.

25. The transmitter of claim 17, wherein the n consecutive OFDM symbols are transmitted concurrently with the k consecutive OFDM symbols, and n is an integer multiple of k.

26. The transmitter of claim 25, wherein k=7 and n=14.

27. The transmitter of claim 17, wherein:

the first OFDM symbol of the k consecutive OFDM symbols has a cyclic prefix that is longer than a cyclic prefix of each one of the remaining OFDM symbols of the k consecutive OFDM symbols; and

the first OFDM symbol of then consecutive OFDM symbols has a cyclic prefix that is longer than a cyclic prefix of each one of the remaining OFDM symbols of the n consecutive OFDM symbols.

28. The transmitter of claim 17, wherein a trailing edge of the first OFDM symbol of the k consecutive OFDM symbols is aligned with a trailing edge of the second OFDM symbol of the n consecutive OFDM symbols.

29. The transmitter of claim 17, wherein the second subcarrier spacing is an integer multiple of the first subcarrier spacing.

30. The transmitter of claim 29, wherein the integer multiple is a power of two.

31. The transmitter of claim 17, wherein the first subcarrier spacing is 15 kHz×

2ⁱ, where i is an integer and i≥

0, and wherein the second subcarrier spacing is 15 kHz×

2^j, where j is an integer and j>

i.

32. The transmitter of claim 17, wherein the transmitter is part of a base station.