TELECOMMUNICATIONS APPARATUS AND METHOD

• US 20180270795A1
• Filed: 01/06/2016
• Published: 09/20/2018
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: MORIOKA, Yuichi, BEALE, Martin Warwick
• Granted Patent: US 10,448,382 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1838 for semi-reliable protocols, e.g. for less sensitive applications such as streaming video buffer level management for video bitstream receiver H04N21/44004
• CPC Class Codes: H04L 1/1845 Combining techniques, e.g. code combining
• CPC Class Codes: H04L 1/1877 for semi-reliable protocols, e.g. for less sensitive applications like streaming video buffer level management for video bitstream control arrangements H04N21/44004
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/189 Transmission or retransmission of more than one copy of a message
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• 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: Y02D 30/70 in wireless communication networks

Abstract

A method of transmitting downlink data in a mobile communications system, wherein the mobile communications system comprises a base station configured to communicate wireless signals to one or more terminal devices. The method comprises receiving an indicator of a maximum number of downlink repetitions “Nmax” currently accepted by a terminal device, wherein a number of downlink repetitions indicates a number of times that the same signal is transmitted to the terminal device; setting an actual number of downlink repetitions “Ntx” so that the actual number of downlink repetitions meets the condition Ntx≤Nmax; and transmitting the downlink data, to the terminal device, wherein the downlink data is transmitted via a signal transmitted a number of times equals to the actual number of downlink repetitions.

Claims

1. A method of transmitting downlink data in a mobile communications system, wherein the mobile communications system comprises a base station configured to communicate wireless signals to one or more terminal devices, the method comprising:

receiving an indicator of a maximum number of downlink repetitions “

Nmax”

currently accepted by a terminal device, wherein a number of downlink repetitions indicates a number of times that the same signal is transmitted to the terminal device;

setting an actual number of downlink repetitions “

Ntx”

so that the actual number of downlink repetitions meets the condition Ntx≤

Nmax; and

transmitting the downlink data, to the terminal device, wherein the downlink data is transmitted via a signal transmitted a number of times equals to the actual number of downlink repetitions.

2. A method according to claim 1 wherein the setting of the actual number of downlink repetition is, based on the type of downlink data to be transmitted to the terminal device.

3. A method according to claim 2 wherein the type of downlink data comprises a priority level for the downlink data.

4. A method according to claim 2 wherein the type of downlink data is at least partially derived from the type of service or application requesting the data transmission.

5. A method according to claim 1 comprising:

retrieving a reference number of downlink repetitions for the terminal device,

wherein the setting of the actual number of downlink repetitions is based on a comparison between the maximum number of downlink repetitions “

Nmax”

currently accepted by a terminal device and the reference number of downlink repetitions.

6. A method according to claim 1 wherein the setting of the actual number of downlink repetitions comprises:

deciding whether to transmit the downlink data to the terminal device based on the type of downlink data;

if it is decided to transmit the downlink data, setting the actual number of downlink repetitions so that it meets the condition 1≤

Ntx≤

Nmax; and

if it is decided not to transmit the downlink data, setting the actual number of downlink repetitions to zero.

7. A method according to claim 1 wherein the base station is configured to communicate wireless signals to the one or more terminal devices in a series of time sub-frames, wherein sub-frames comprise a first section for resource allocation and a second section for data transmission and wherein transmitting the downlink data to the terminal device comprises:

transmitting a resource allocation message for the downlink data and for the terminal device via a first set of one or more sub-frames in the first section; and

subsequently transmitting the downlink data in a second set of N sub-frames in the second section wherein N is the actual number of repetitions.

8. A method according to claim 7 wherein the sub-frames are grouped in a first time period for repeating resource allocation signals and in a second time period for repeating data signals and wherein

the first set of one or more sub-frames consists of adjacent sub-frames starting at the start of the first time period;

and

the second set of one or more sub-frames consists of adjacent sub-frames starting at the start of the second time period.

9. A method according to claim 7, wherein the first set of one or more sub-frames consists of N sub-frames.

10. A method according to claim 1 wherein the actual number of downlink repetitions is set based on indications of success for past transmissions to the terminal device.

11. (canceled)

12. Circuitry for a base station for transmitting downlink data in a mobile communications system, wherein the base station is configured to communicate wireless signals to one or more terminal devices and wherein the circuitry comprises a controller element and a transceiver element configured to operate together to:

receive an indicator of a maximum number of downlink repetitions “

Nmax”

supported by a terminal device, wherein a number of downlink repetitions indicates a number of times that the same signal is transmitted to the terminal device;

set an actual number of downlink repetitions “

Ntx”

so that the actual number of downlink repetitions meets the condition Ntx≤

Nmax; and

transmit the downlink data, to the terminal device, wherein the downlink data is transmitted via a signal transmitted a number of times equals to the actual number of downlink repetitions.

13. A method of receiving downlink data at a terminal in a mobile communications system, wherein the mobile communications system comprises a base station configured to communicate wireless signals to one or more terminal devices, the method comprising:

obtaining a maximum number of downlink repetitions “

Nmax”

for downlink transmissions to the terminal wherein a number of downlink repetitions indicates a number of times that the same signal is transmitted to the terminal device;

setting the value of a decoding number of repetitions for downlink data “

Ndec”

at a first value wherein 1≤

Ndec≤

Nmax; and

attempting to decode downlink data transmissions based on the decoding number of repetitions for downlink data.

14. A method according to claim 13 wherein the method further comprises:

if the downlink data transmissions have not been successfully decoded for the decoding number of repetitions for downlink data;

if the Ndec is equal to the Nmax, detecting an unsuccessful decoding of the downlink data transmissions; and

if the Ndec is not equal to the Nmax, selecting a new Ndec which is greater than and not equal to the previous Ndec and which is less than or equal to the Nmax, and returning to the step of attempting to decode downlink data transmissions.

15. A method according to claim 13 wherein the first value is one.

16. A method according to claim 13 wherein the first value is Nmax.

17. A method according to claim 13, wherein the base station is configured to communicate the wireless signals to the one or more terminal devices in a series of time sub-frames, wherein sub-frames comprise a first section for resource allocation and a second section for data transmission and wherein attempting to decode downlink data transmissions comprises:

attempting to decode resource allocation transmissions in the first section of sub-frames; and

if resource allocation transmissions in the first section of sub-frames have been successfully decoded, attempting to decode the data transmissions in the second sections of sub-frames based on the Ndec and on the decoded resource allocation signals.

18. A method according to claim 17 wherein attempting to decode resource allocation transmissions comprises attempting to decode resource allocation transmissions based on a decoding number of downlink repetition for resource allocation signals “

Ndec-ra” and

wherein, if resource allocation transmissions in the first section of sub-frames have been successfully decoded, attempting to decode the data transmissions in the second sections of sub-frames comprises attempting to decode the data transmissions in the second section of sub-frames with Ndec set to the Ndec-ra for the successful decoding of the resource allocation transmissions.

19. A method according to claim 17 wherein the method comprises

obtaining a maximum number of downlink repetitions “

Nmax-ra”

for downlink resource allocation transmissions to the terminal;

and wherein attempting to decode resource allocation transmissions comprises;

attempting to decode resource allocation transmissions based on a decoding number of downlink repetition for resource allocation signals “

Ndec-ra”

, wherein the Ndec-ra is first set at a second value such that 1≤

Ndec-ra≤

Nmax-ra;

if resource allocation signals in the first section of sub-frames have not been successfully decoded;

if the Ndec-ra is equal to Nmax-ra, detecting an unsuccessful decoding of the downlink resource allocation transmissions;

if the Ndec-ra is not equal to Nmax-ra, selecting a new Ndec-ra which is greater than and not equal to the previous Ndec-ra and which is less than or equal to Nmax-ra, and returning to the step of attempting to decode resource allocation transmissions.

20. A method according to claim 19 wherein the second value is one.

21. A method according to claim 19 wherein the second value is Nmax-ra.

22. A method according to claim 19 wherein Nmax-ra is equal to Nmax.

23. A method according to claim 17, wherein the sub-frames are grouped in a first time period for repeating resource allocation signals and in a later second time period for repeating data signals and wherein, if resource allocation transmissions are successfully decoded for sub-frames of the first-time period, the step of attempting to decode the data signals is carried out for sub-frames of the second time period.

24. A method according to claim 23 comprising, in the event that resource allocation transmissions in the first section of sub-frames have not been successfully decoded or that no resource allocation transmissions for the terminal have been received, turning off a receiver for the terminal for the duration of the second period.

25. A terminal device for receiving downlink data at a terminal in a mobile communications system, wherein the mobile communications system comprises a base station configured to communicate wireless signals to one or more terminal devices, the terminal device being configured to:

obtain a maximum number of downlink repetitions “

Nmax”

for downlink transmissions to the terminal wherein a number of downlink repetitions indicates a number of times that the same signal is transmitted to the terminal device;

set the value of a decoding number of repetitions for downlink data “

Ndec”

at a first value wherein 1≤

Ndec≤

Nmax; and

attempt to decode downlink data transmissions based on the decoding number of repetitions for downlink data.

26-32. -32. (canceled)