# US 10,873,931 B2 · Downlink control method and apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,873,931 B2
- Document ID: US10873931B2
- Status: Granted
- Kind: B2
- Application number: 15/761,074
- Filed: 2016-08-10
- Published: 2018-10-25
- Granted: 2020-12-22
- Earliest claimed: 2015-09-18
- Assignees: Zte Corporation
- Applicants: Zte Corporation
- Inventors: Jing Shi; Shuqiang Xia; Wei Gou; Bo Dai; Qian Dai
- Web page: https://patentgrep.com/patent/US10873931B2

## CPC

- H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal
- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04L 5/0092: {Indication of how the channel is divided}
- H04L 5/0094: {Indication of how sub-channels of the path are allocated}
- H04L 27/2602: {Signal structure}
- H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT}
- H04L 27/2603: {Signal structure ensuring backward compatibility with legacy system}
- H04W 72/0446: Resources in time domain, e.g. slots or frames
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A downlink control method and apparatus are disclosed. The method includes: a base station determining at least one downlink control channel in a first downlink control channel and a second downlink control channel, including: determining to use the second downlink control channel in a short transmission time interval (TTI) which is out of a scheduling range of the first downlink control channel, or determining the downlink control channel used in the short TTI according to pre-definition or system configuration information; and the base station transmitting downlink control information (DCI) by using the determined downlink control channel.

## Claims

### Claim 1

A downlink control method, comprising:
determining, by a base station, at least one downlink control channel in a first downlink control channel and a second downlink control channel, wherein the determining comprises: determining the downlink control channel used in short transmission time intervals (TTIs) according to pre-definition; and
transmitting, by the base station, downlink control information (DCI) by using the determined downlink control channel;
wherein the pre-definition comprises a part of the short TTIs uses the second downlink control channel;
wherein a part of the short TTIs uses the second downlink control channel comprises except that a first short TTI do not use the second downlink control channel, and remaining short TTIs use the second downlink control channel;
wherein the first downlink control channel is a physical downlink control channel (PDCCH), and the second downlink control channel is a short physical downlink control channel (SPDCCH); each of the short TTIs is a TTI a time domain length of that is smaller than 1 millisecond; and the SPDCCH is a physical downlink control channel that occupies a part of resource elements within the time domain length of one of the short TTIs, and a time domain length of the SPDCCH is smaller than or equal to the time domain length of an occupied short TTI;
wherein the DCI is used for notifying a terminal of a corresponding traffic receiving way, and the traffic receiving way comprises at least one of: in response to determining that the DCI of the terminal is located in the PDCCH, receiving a traffic at the first short TTI or receiving a traffic at a TTI with the time domain length of 1 millisecond.

### Claim 2 (depends on 1)

The method according to claim 1, wherein a time domain length of the short TTI is predefined or notified by a signaling;
the signaling comprises at least one of: system information block (SIB) information, a radio resource control (RRC) message or a physical layer signaling;
the physical layer signaling comprising at least one of the DCI or control format indication (CFI).

### Claim 3 (depends on 1)

The method according to claim 1, wherein
the SPDCCH, within the short TTI where the SPDCCH is located, uses resource elements within the short TTI with a short physical downlink shared channel (SPDSCH) according to at least one of: time division multiplexing, frequency division multiplexing, code division multiplexing, or time frequency division multiplexing; and
the SPDSCH is a physical downlink shared channel that occupies a part or all of the resource elements within the time domain length of the short TTI, and a time domain length of the physical downlink control channel is smaller than or equal to the time domain length of the occupied short TTI.

### Claim 4 (depends on 1)

The method according to claim 1, wherein
at least one of the PDCCH or the SPDCCH is in the same short TTI with scheduled downlink data information; and
the determining to use the second downlink control channel in the short TTI that is out of a scheduling range of the first downlink control channel comprises:
determining that the SPDCCH is used in one or more short TTIs behind a PDCCH region.

### Claim 5 (depends on 4)

The method according to claim 4, wherein
a size of a resource block group (RBG) serving as a granularity of resource allocation (RA) used by scheduling the short TTI is larger than or equal to a size of a RBG used by scheduling the TTI with the time domain length of 1 millisecond under a same system bandwidth.

### Claim 6 (depends on 4)

The method according to claim 4, wherein determining a transport block size (TBS) configuration table used by scheduling the short TTI comprises:
according to a proportion Y of the time domain length of the short TTI to 1 millisecond, multiplying a TBS in a predetermined TBS configuration table by Y, wherein 0%<Y<100%; and
rounding up or down of a product to obtain the TBS in the TBS configuration table used by scheduling the short TTI.

### Claim 7 (depends on 4)

The method according to claim 4, wherein
in response to determining that the time domain length of the short TTI is 0.5 millisecond, the PDCCH schedules downlink (DL) traffic channels in even short TTIs, the SPDCCH schedules DL traffic channels in odd short TTIs; and the PDCCH and a SPDCCH schedule uplink (UL) traffics of a subframe n+k, k is at least one of: 2, 4 or 8, n is a serial number of a current subframe.

### Claim 8 (depends on 1)

The method according to claim 1, wherein
at least one of the PDCCH or the SPDCCH is located in the same or different short TTIs with a scheduled downlink data information; and
the determining the downlink control channel used in the short TTI according to the pre-definition comprises:
determining that, in a subframe behind the TTI where the PDCCH is located, a part of short TTIs uses the SPDCCH, or all the short TTIs use the SPDCCH.

### Claim 9 (depends on 8)

The method according to claim 8, wherein the determining the downlink control channel used in the short TTI according to the pre-definition comprises:
in response to determining that the time domain length of the short TTI is 0.5 millisecond, determining that the SPDCCH is not used; and determining whether a SPDSCH occupies even short TTIs or odd short TTIs according to 1 bit predetermined in the DCI in the PDCCH; and
in response to determining that a subframe, the time domain length of that is 1 millisecond, comprises x short TTIs, indicating that data scheduled by the SPDCCH or PDCCH is located in one or more short TTIs in the subframe by using m bits in the DCI in the SPDCCH or PDCCH, wherein x is a positive integer, and m≤x.

### Claim 10

A downlink control method, comprising:
determining, by a terminal, at least one downlink control channel in a first downlink control channel and a second downlink control channel, wherein the determining comprises: determining the downlink control channel used in short transmission time intervals (TTIs) according to pre-definition; and
receiving, by the terminal, downlink control information (DCI) by using the determined downlink control channel;
performing, by the terminal, a corresponding traffic receiving way according to the detected DCI;
wherein the pre-definition comprises a part of the short TTIs uses the second downlink control channel;
wherein a part of the short TTIs uses the second downlink control channel comprises except that a first short TTI do not use the second downlink control channel, and remaining short TTIs use the second downlink control channel;
wherein the first downlink control channel is a physical downlink control channel (PDCCH), and the second downlink control channel is a short physical downlink control channel (SPDCCH); each of the short TTIs is a TTI a time domain length of that is smaller than 1 millisecond; and the SPDCCH is a physical downlink control channel that occupies a part of resource elements within the time domain length of one of the short TTIs, and a time domain length of the SPDCCH is smaller than or equal to the time domain length of an occupied short TTI;
wherein the traffic receiving way comprises at least one of: in response to determining that the DCI of the terminal is located in the PDCCH, receiving a traffic at the first short TTI or receiving a traffic at a TTI with the time domain length of 1 millisecond.

### Claim 11

A downlink control apparatus, that is disposed on a base station and comprises a processor, a storage device and a transmitter, wherein the storage device stores processor-executable programs, and the programs comprise a first determining module;
wherein the first determining module is configured to determine at least one downlink control channel in a first downlink control channel and a second downlink control channel, comprising: determining the downlink control channel used in short transmission time intervals (TTIs) according to pre-definition; and
the transmitter is configured to transmit downlink control information (DCI) by using the determined downlink control channel;
wherein the pre-definition comprises a part of the short TTIs uses the second downlink control channel;
wherein a part of the short TTIs uses the second downlink control channel comprises except that a first short TTI do not use the second downlink control channel, and remaining short TTIs use the second downlink control channel;
wherein the first downlink control channel is a physical downlink control channel (PDCCH), and the second downlink control channel is a short physical downlink control channel (SPDCCH); each of the short TTIs is a TTI a time domain length of that is smaller than 1 millisecond; and the SPDCCH is a physical downlink control channel that occupies a part of resource elements within the time domain length of one of the short TTIs, and a time domain length of the SPDCCH is smaller than or equal to the time domain length of an occupied short TTI;
wherein the DCI is used for notifying a terminal of a corresponding traffic receiving way, and the traffic receiving way comprises at least one of: in response to determining that the DCI of the terminal is located in the PDCCH, receiving a traffic at the first short TTI or receiving a traffic at a TTI with the time domain length of 1 millisecond.