Frequency multiplexing of first and second OFDMA transmissions

Patent metadata

Field	Value
Publication number	US-11700534-B2
Application number	US-201716766831-A
Country	US
Kind code	B2
Filing date	Dec 4, 2017
Priority date	Dec 4, 2017
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

A wireless communications system and a method for frequency multiplexing a first (LAA) OFDMA transmission and a second (Wi-Fi) OFDMA transmission on a shared radio channel spanning at least partly a common bandwidth. The system determines an unallocated frequency band available beside a first frequency band intended for a first transmission and sends a sharing request comprising information about the unallocated band. The system decides to use the unallocated band in a second frequency band in the shared channel. The system sends a legacy preamble and a first part of a Wi-Fi preamble spanning the shared channel. The first transmission is sent in the first band such that an end time point of the first part of the Wi-Fi preamble coincides with a start time point of the first transmission. Further, the system sends a second part of the Wi-Fi preamble and the second transmission in the second band.

First claim

The invention claimed is:

1. A method performed in a wireless communications system for frequency multiplexing a first Orthogonal Frequency Division Multiple Access (OFDMA) transmission and a second OFDMA transmission on a shared radio channel spanning at least partly a common bandwidth, wherein a first network node and a first wireless device are operating in a first wireless communications network, and a second network node and a second wireless device are operating in a second wireless communications network, and wherein the method comprises:
determining an unallocated frequency band available beside a first frequency band intended/allocated for a first OFDMA transmission in the shared radio channel;
sending a sharing request comprising information about the unallocated frequency band;
deciding to use the unallocated band in a second frequency band in the shared radio channel;
conducting a contention procedure;
sending a legacy (L) preamble spanning the shared radio channel;
sending a first part of a High Efficiency (HE) preamble spanning the shared radio channel;
sending a first OFDMA transmission in the first frequency band, such that an end point of time of the first part of the HE preamble coincides with a start point of time of the first OFDMA transmission; and
sending a second part of the HE preamble and the second OFDMA transmission in the second frequency band.

2. The method according to claim 1 , wherein the method comprises:
detecting the sent L preamble, and wherein the sending of the second part of the HE preamble and the second OFDMA transmission in the second frequency band comprises:
sending the second part of the HE preamble and the second OFDMA transmission such that an end point of time of the L preamble coincides with a start point of time of the second part of the HE preamble and such that an end point of time of the second part of the HE preamble coincides with a start point of time of the second OFDMA transmission.

3. The method according to claim 1 , wherein the sharing request comprises information about a subframe boundary indicating the start point of time of the first OFDMA transmission.

4. The method according to claim 1 , wherein the method comprises:
providing a guard band between the first frequency band and the second frequency band in the shared radio channel, and wherein the guard band size for example is a multiple of a subcarrier spacing in the first or second OFDMA transmission.

5. The method according to claim 1 , wherein the shared radio channel comprises the first frequency band, an optional guard band and the second frequency band, and wherein the first frequency band, the optional guard band and the second frequency band are non-overlapping frequency bands.

6. The method according to claim 1 , comprising:
sending a sharing reply comprising information about the L preamble.

7. The method according to claim 1 , wherein the sending of the first OFDMA transmission is performed by the first network node, and wherein the sending of the second part of the HE preamble and the second OFDMA transmission are performed by the second network node.

8. The method according to claim 7 , wherein the first and second network nodes are collocated at the same location, and wherein the sending of the L preamble, and the sending of the first part of the HE preamble is performed by the first network node.

9. The method according to claim 7 , wherein the first and second network nodes are collocated at the same location, wherein the sending of the L preamble and the sending of the first part of the HE preamble are performed by the second network node.

10. The method according to claim 9 , wherein the conducting of the contention procedure is performed by the first and second network nodes.

11. The method according to claim 7 , wherein the first and second network nodes are arranged at different locations, wherein the sending of the L preamble is performed simultaneously by the first and second network nodes, and wherein the sending of the first part of the HE preamble is performed by the second network node:
performing synchronization to a subframe boundary of the first network node.

12. A method performed by a first network node for frequency multiplexing a first Orthogonal Frequency Division Multiple Access (OFDMA) transmission and a second OFDMA transmission on a shared radio channel spanning at least partly a common bandwidth, wherein the first network node and a first wireless device are operating in a first wireless communications network, and a second network node and a second wireless device are operating in a second wireless communications network, and wherein the method comprises:
determining an unallocated frequency band available beside a first frequency band intended/allocated for a first OFDMA transmission in the shared radio channel;
sending, to the second network node, a sharing request comprising information about the unallocated frequency band in a second frequency band in the shared radio channel;
conducting a contention procedure;
sending, to the first wireless device, the first OFDMA transmission in the first frequency band, such that an end point of time of a first part of a High Efficiency (HE) preamble coincides with a start point of time of the first OFDMA transmission.

13. The method according to claim 12 , wherein the sharing request comprises information about a subframe boundary indicating the start point of time of the first OFDMA transmission.

14. The method according to claim 12 , wherein the method comprises:
providing a guard band between the first frequency band and the second frequency band in the shared radio channel, and wherein the guard band size is for example a multiple of a subcarrier spacing in the first or second OFDM transmission.

15. The method according to claim 12 , wherein the shared radio channel comprises the first frequency band, an optional guard band and the second frequency band, and wherein the first frequency band, the optional guard band and the second frequency band are non-overlapping frequency bands.

16. The method according to claim 12 , comprising:
receiving, from the second network node, a sharing reply comprising information about a Legacy (L) preamble.

17. The method according to claim 12 , wherein the first and second network nodes are collocated at the same location, and wherein the method comprises:
sending, to the first wireless device, a Legacy (L) preamble spanning the shared radio channel;
sending, to the first wireless device, the first part of the HE preamble spanning the shared radio channel.

18. A method performed by a second network node for frequency multiplexing a first Orthogonal Frequency Division Multiple Access (OFDMA) transmission and a second OFDMA transmission on a shared radio channel spanning at least partly a common bandwidth, wherein a first network node and a first wireless device are operating in a first wireless communications network, and the second network node and a second wireless device are operating in a second wireless communications network, and wherein the method comprises:
receiving, from the first network node, a sharing request comprising information about an unallocated frequency band available beside a first frequency band intended/allocated for a first OFDMA transmission in the shared radio channel;
deciding to use the unallocated band in a second frequency band in the shared radio channel;
conducting a contention procedure; and
sending, to the second wireless device, a second part of a High Efficienc

Assignees

• Ericsson Telefon Ab L M

Inventors

• Nilsson Thomas
• Sundman Dennis

Classifications

• H04W74/0891

  for synchronized access · CPC title

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04W16/14 Primary

  Spectrum sharing arrangements {between different networks} · CPC title

• H04W72/0453 Primary

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title