METHOD AND EQUIPMENT FOR DATA TRANSMISSION ON UNLICENSED BAND

• US 20170111889A1
• Filed: 05/14/2015
• Published: 04/20/2017
• Est. Priority Date: 05/16/2014
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Li, Yingyang, Sun, Chengjun, Fu, Jingxing
• Application Number:
  US15/311,840
• Publication Number:
  US 20170111889A1
• Time in Patent Office: Days
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0096 Indication of changes in allocation
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

The present invention provides a method for data transmission on an unlicensed band, comprising the steps of: receiving, by UE, configuration information, the configuration information configuring a cell where the UE works on an unlicensed and; and, receiving, by the UE, control information, and performing data transmission on the unlicensed band according to the control information. The present application further discloses a method for data transmission on an unlicensed band, UE and a base station. By the technical solutions provided by the present invention, a wireless channel can be reserved for the data transmission of UE on an unlicensed band, and the data transmission of the UE on the unlicensed band and the frequency occupation of a WiFi system are coordinated, so that the mutual interference between the data transmission of the UE on the unlicensed band and the WiFi system is avoided.

Claims

1. A method for data transmission on an unlicensed band, comprising the steps of:

receiving, by a UE, configuration information, the configuration information configuring a cell where the UE works on an unlicensed band; and

receiving, by the UE, control information, and performing data transmission on the unlicensed band according to the control information.

2. The method according to claim 1, characterized in that,

the method further comprises the step of:

when detecting that a wireless channel is idle, sending a wireless fidelity (WiFi) frame, and setting a duration field of the WiFi frame as a time period for reserving the wireless channel; and

the performing data transmission on the unlicensed band is specifically as follows;

performing data transmission on the unlicensed band within the time period for reserving the wireless channel,

wherein a receiver address of the WiFi frame is different from an address of a WiFi station (WiFi STA).

4. The method according to claim 1, characterized in that,

the method further comprises the step of:

when detecting that a wireless channel is idle, sending a signal structure containing a physical layer convergence protocol (PLCP) preamble, a PLCP header and valid data transmission in accordance with 802.11, wherein a coding rate (RATE) and a length (LENGTH) in the PLCP header indicate a time period for reserving the wireless channel; and

the performing data transmission on the unlicensed band is specifically as follows;

performing data transmission on the unlicensed band within the time period for reserving the wireless channel,

the performing data transmission on the unlicensed band is specifically as follows;

reserving a wireless channel, and performing data transmission within the time period for reserving the wireless channel, and not performing data transmission at an interval between two times of reservation of the wireless channel,

the performing data transmission on the unlicensed band comprises;

in a part of subframes of a cell on the unlicensed band, reserving the wireless channel first and then performing data transmission within the time period for reserving the wireless channel; and

, in another part of subframes of the cell on the unlicensed band, performing data transmission in a power less than a preset power.

7. The method according to claim 4, characterized in that,

the UE obtains, by a physical downlink control channel (PDCCH) in a primary cell (Pcell), a time period for reserving the wireless channel in the cell on the unlicensed band;

wherein, the UE works in the Pcell and the cell on the unlicensed band in a carrier aggregation (CA) mode.

8. The method according to claim 1, characterized in that,

the method further comprises the step of:

performing carrier sensing from moment T-T0, where T is a moment intended for data transmission in the cell, and T0 is a time advance for carrier sensing; and

the performing data transmission on the unlicensed band is specifically as follows;

starting sending a signal at a corresponding moment, when detecting a wireless channel is idle and a preset condition is satisfied.

9. The method according to claim 8, characterized in that,

T0 is equal to a time of one orthogonal frequency division multiplexing (OFDM) symbol,

moment T-T0 is a starting position of a last OFDM symbol of each subframe;

or

moment T-T0 is a starting position of a first OFDM symbol of each subframe;

or

moment T-T0 is a starting position of a last OFDM symbol of a last subframe within Pms cycle;

or

moment T-T0 is a starting position of a first OFDM symbol of a beginning subframe within Pms cycle;

where, P is a cycle parameter.

10. The method according to claim 8, characterized in that,

where the preset condition is that it is detected that a wireless channel is idle before moment T, the corresponding moment is moment T;

or

where the preset condition is that an idle duration of the wireless channel is equal to a time length TL, the corresponding moment is a moment when the idle duration of the wireless channel is equal to TL;

or

where the preset condition is that the idle duration of the wireless channel reaches the time length TL and the wireless channel remains idle within a backoff time generated at random, the corresponding moment is a moment when the backoff time is over;

or

where the preset condition is that when it is detected that a first time point when the wireless channel becomes idle is prior to moment T while the first time point after being superimposed by a time length TL falls behind moment T, and the wireless channel remains idle until moment T, the corresponding moment is moment T;

or

where the preset condition is that the idle duration of the wireless channel reaches the time length TL, a second time point when the idle duration reaches the time length TL is prior to moment T, the second time point after being superimposed by a backoff time generated at random falls behind moment T, and the wireless channel remains idle until moment T, the corresponding moment is moment T;

wherein, TL is a fixed time length.

11. The method according to claim 10, characterized in that,

if the corresponding moment falls behind moment T, the method further comprises the step of:

starting sending a fill-in signal from the corresponding moment, and transmitting only a complete OFDM symbol in a rear part of a subframe; and

the performing data transmission on the unlicensed band is specifically as follows;

starting sending valid data from a boundary of the OFDM symbol.

12. The method according to claim 10, characterized in that,

if the corresponding moment is prior to moment T, the method further comprises the step of:

starting sending a fill-in signal from the corresponding moment until moment T; and

the performing data transmission on the unlicensed band is specifically as follows;

starting sending valid data from moment T.

14. The method according to claim 1, characterized in that,

the method further comprises the step of:

preferably scheduling a physical resource block (PRB) in an effective bandwidth of the cell, overlapped with a guard band in a WiFi system, when performing data transmission on the unlicensed band,

the method further comprises the step of during scheduling, not scheduling a PRB in a vicinity of a pilot subcarrier of the WiFi system;

or, scheduling a PRB in the vicinity of the pilot subcarrier of the WiFi system in a power less than a preset power,

the UE acquires, by a downlink control information (DCI) format in a primary cell (Pcell), whether a cell on the unlicensed band performs data transmission within a current cycle;

or, the UE acquires, by the DCI in the Pcell, a number of wireless frames or a number of subframes used by the cell on the unlicensed band for data transmission within a cycle P;

wherein, the UE works in the Pcell and the cell on the unlicensed band in a CA mode, and the UE performs downlink transmission in the cell on the unlicensed band only.

17. The method according to claim 1, characterized in that,

the UE acquires, by a DCI format in a primary cell (Pcell), that the cell on the unlicensed band performs data transmission within a current cycle according to a configuration of uplink/downlink subframe distribution, or that resources of the cell on the unlicensed band are not used for data transmission within the current cycle;

or, the UE acquires, by the DCI format in the Pcell, a number of wireless frames or a number of subframes used by the cell on the unlicensed band for data transmission within a cycle P;

wherein, the UE works in the Pcell and the cell on the unlicensed band in a CA mode, and the cell on the unlicensed band is semi-statically configured with an uplink/downlink subframe distribution,

the UE acquires, by the DCI format in the Pcell, the configuration of uplink/downlink subframe distribution followed by the cell on the unlicensed band within the current cycle, or that the resources of the cell on the unlicensed band are not used for data transmission within the current cycle, or that all subframes of the cell on the unlicensed band are used for downlink transmission within the current cycle;

wherein, the UE works in the Pcell and the cell of the unlicensed band in a CA mode, and the uplink/downlink subframe distribution of the cell on the unlicensed band is dynamically configured.

19. The method according to claim 1, characterized in that the performing data transmission on the unlicensed band comprises:

by the UE, when scheduled to perform uplink transmission, performing uplink transmission in an uplink subframe according to uplink scheduling, whether a wireless channel is idle or not;

or

by the UE, when scheduled to perform uplink transmission, detecting a state of the wireless channel before a corresponding uplink subframe, performing uplink transmission in the uplink subframe if a signal level of the wireless channel is lower than a preset threshold;

or otherwise, skipping this time of uplink transmission.

20. The method according to claim 19, characterized in that,

the performing uplink transmission in an uplink subframe comprises:

by the UE, when scheduled to perform uplink transmission in a subframe n, if the UE has sent an uplink signal in a subframe n−

1, continuing performing uplink transmission in the subframe n; and

if the UE has not sent any uplink signal in the subframe n−

1, performing carrier sensing first, and then performing uplink transmission in the subframe n when the signal level of the wireless channel is lower than a preset threshold.

21. The method according to claim 1, characterized in that the method further comprises the steps of:

when receiving a PDCCH order from a base station and triggering a physical random access channel (PRACH) transmission, detecting, by the UE, a state of a wireless channel before a subframe with corresponding PRACH resources or within X ms in a front of the subframe,

by the UE, not responding to the PDCCH order if the wireless channel is busy;

or

by the UE, not sending a PRACH preamble on the PRACH resources when the wireless channel is busy, continuing attempting subsequent PRACH resources until available PRACH resources are found, and sending a PRACH preamble on the available PRACH resources;

or

by the UE, detecting the state of the wireless channel within a time window, and not responding to the PDCCH order when there is no available PRACH resource found in the time window.

22. The method according to claim 1, characterized in that the method further comprises the steps of:

by the UE, for one PRACH resource, performing carrier sensing within a preset time period prior to a subframe with the PRACH resource and within X ms in a front of the subframe with the PRACH resource;

or, for one PRACH resource, performing carrier sensing only within X ms in the front of the subframe with the PRACH resource; and

by the UE, sending a PRACH preamble when the UE detects that a wireless channel is idle and a preset condition is satisfied.

23. The method according to claim 22, characterized in that,

the preset condition is that the UE detects that the wireless channel is busy;

or that the wireless channel is idle and remains idle within a time length TL, TL being a fixed time length,

if a moment satisfying the preset condition is prior to a boundary of the subframe, the method further comprises the steps of;

by the UE, sending a fill-in signal to the boundary of the subframe, and then starting sending a PRACH preamble,

if the moment satisfying the preset condition falls behind the boundary of the subframe, the method further comprises the steps of;

by the UE, truncating a front part of the PRACH preamble and then sending the truncated PRACH preamble,

if the moment satisfying the preset condition falls behind the boundary of the subframe, the method further comprises the step of by the UE, sending a complete PRACH preamble.

3. (canceled)

5. (canceled)

6. (canceled)

13. (canceled)

15. (canceled)

16. (canceled)

18. (canceled)

24-26. -26. (canceled)

27. UE for data transmission on an unlicensed band, comprising:

a configuration module, configured to receive configuration information and configure, according to the configuration information, a cell where the UE works on an unlicensed band; and

a transmission module, configured to receive control information and perform data transmission on the unlicensed band according to the control information.

28. A method for data transmission on an unlicensed band, applied to a base station to which a cell on the unlicensed band belongs, comprising the steps of:

sending, by the base station, control information to a UE, the control information being used for controlling the data transmission of the UE on an unlicensed band; and

performing, by the base station and the UE, data transmission on the unlicensed band.

29. The method according to claim 28, characterized in that,

the method further comprises the steps of:

when detecting that a wireless channel is idle, sending a WiFi frame and setting a duration field of the WiFi frame as a time period for reserving the wireless channel;

or,

when detecting that a wireless channel is idle, sending a signal structure containing a PLCP preamble, a PLCP header and valid data transmission in accordance with 802.11, wherein a rate and a length in the PLCP header indicate a time period for reserving the wireless channel; and

the performing data transmission on the unlicensed band is specifically as follows;

performing data transmission on the unlicensed band within the time period for reserving the wireless channel.

30. A base station for data transmission on an unlicensed band, comprising:

a control module, configured to send control information to UE, the control information being used for controlling the data transmission of the UE on an unlicensed band; and

a transmission module, configured to perform, together with the UE, data transmission on the unlicensed band.