CN108347783B

CN108347783B - sTTI uplink scheduling information transmission method

Info

Publication number: CN108347783B
Application number: CN201710057885.2A
Authority: CN
Inventors: 陈艳霞; 郑辰; 池连刚; 冯绍鹏
Original assignee: Potevio Information Technology Co Ltd
Current assignee: Potevio Information Technology Co Ltd
Priority date: 2017-01-23
Filing date: 2017-01-23
Publication date: 2021-06-18
Anticipated expiration: 2037-01-23
Also published as: CN108347783A

Abstract

The application discloses a method for transmitting uplink scheduling information of an sTTI, which comprises the following steps: determining the format of the sTTI; determining a binding scheduling scheme of the sTTI and determining a corresponding scheduling format; and indicating the scheduling format of the sTTI by using a frequency hopping flag bit and a resource allocation mode indication in the traditional TTI DCI 0. By applying the technical scheme disclosed by the application, the RS overhead can be reduced, and better channel estimation performance is ensured.

Description

sTTI uplink scheduling information transmission method

Technical Field

The present application relates to the field of mobile communications technologies, and in particular, to a method for transmitting uplink scheduling information of an sTTI.

Background

In recent years, wireless communication technology has been rapidly developed, and modern society has entered the information age. None of the various communication technologies have moved toward the goal of "high rate, low latency", and increasingly stringent requirements for latency have been explicitly written into the design standards for each communication technology. 3GPP has already established terms for "reduced latency techniques", which define a short Transmission time Interval (sTTI) for carrying low latency traffic, in order to distinguish it from the conventional legacy TTI. Uplink authorization information of the sTTI is transmitted in a short physical downlink control channel (sPDCCH), and a downlink control information format needs to be redefined for bearing the uplink authorization information based on a concept of two-stage transmission of the downlink control information.

Disclosure of Invention

The application provides a method for transmitting uplink scheduling information of an sTTI (received time alignment) so as to reduce RS (Reed-Solomon) overhead and ensure channel estimation performance.

The application discloses a short transmission time interval (sTTI) uplink scheduling information transmission method, which comprises the following steps:

determining the format of the sTTI;

determining a binding scheduling scheme of the sTTI and determining a corresponding scheduling format;

and indicating the scheduling format of the sTTI by using a frequency hopping flag bit and a resource allocation mode indication in the DCI0 of the traditional TTI downlink control information format.

Preferably, the format of sTTI is {3,2,2,2,2,3}, where sTTI0 and sTTI 5 are 3 OFDM symbols long, and sTTI 1 to sTTI 4 are 2 OFDM symbols long.

Preferably, the bundling scheduling scheme of the sTTI includes: single sTTI scheduling, 2 consecutive sTTI bundled scheduling, 3 consecutive sTTI bundled scheduling.

Preferably, the scheduling format of the sTTI includes:

if single-sTTI scheduling is adopted, the scheduling format comprises:

scheduling format 1: a demodulation reference signal DMRS exists in the current sTTI, and the position of the DMRS is the first OFDM symbol of the current sTTI;

scheduling format 2: the DMRS does not exist in the current sTTI, and is positioned at the first OFDM symbol of the previous adjacent sTTI; with the exception of sTTI0 and sTTI3, the DMRS of which is located at the first OFDM symbol of the following adjacent sTTI;

if 2 continuous sTTI bundling scheduling is adopted, the scheduling format is as follows:

scheduling format 3: the DMRS is located at the last OFDM symbol of the first sTTI;

if 3 continuous sTTI bundling scheduling is adopted, the scheduling format is as follows:

scheduling format 4: the DMRS is located in the first OFDM symbol of the second sTTI.

Preferably, the indicating the scheduling format of the sTTI by using the frequency hopping flag bit and the resource allocation manner indication in the conventional TTI DCI0 includes:

and respectively indicating the scheduling formats 1-4 by using different values indicated by the frequency hopping flag bit and the resource allocation mode in the traditional TTI DCI 0.

According to the technical scheme, the transmission method of the uplink scheduling information of the sTTI combines the service characteristics of the 2-symbol sTTI, and fully utilizes the idle bit of the legacy DCI0 to complete the data and RS scheduling format indication of the uplink 2-symbol sTTI. On the premise of not increasing signaling overhead, the number and the positions of the RSs are reasonably arranged according to the condition of bundling and scheduling of different numbers of sTTI, the RS overhead is reduced as much as possible, and better channel estimation performance can be ensured.

Drawings

FIG. 1 is a schematic diagram of an uplink 2 symbol sTTI frame structure according to the present invention;

fig. 2 is a schematic diagram of uplink 2 symbol sTTI data and RS scheduling formats according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below by referring to the accompanying drawings and examples.

DCI0 (downlink control information format 0) for legacy TTI contains information bits as shown in table 1:

TABLE 1

Serial number	Means of	Length (bit)
			1	Carrier indication	0/3
2	Flag for distinguishing between Format 0 and Format 1A	1
			3	Frequency hopping flag bit	1
4	Resource blockAllocation and frequency hopping resource allocation	11 (taking system bandwidth 10M as an example)
			5	Modulation coding scheme and redundancy version	5
6	New data indication	1
			7	Transmission power control commands for scheduled PUSCH	2
8	Uplink index number	2
			9	Downlink index number	2
10	CQI request (bit)	1
			11	SRS request (bit)	0/1
12	Resource allocation mode indication (bit)	1

For an sTTI with a minimum scheduling unit of 2 OFDM symbols (hereinafter referred to as 2-symbol sTTI), if a fixed Reference Signal (RS) is used, a large RS overhead may result. In order to reduce RS overhead, the present invention proposes to indicate the RS position in the uplink grant information by an evolved base station (eNB). Therefore, the invention redefines a downlink control information format based on legacy TTI DCI 0: sDCI0, and defines a data and RS position indication method of 2-symbol sTTI. The method combines the service characteristics of 2-symbol sTTI, uses the frequency hopping flag bit and the resource allocation mode indication bit in the existing DCI0 to indicate the positions of data and RS, does not need to additionally increase signaling bits, and is a reasonable and efficient indication scheme.

For the structure of uplink 2 symbol sTTI, the present invention adopts the format of {3,2,2,2,2,3}, as shown in fig. 1: the length of sTTI0 and sTTI 5 is 3 OFDM symbols, the length of sTTI 1 to sTTI 4 is 2 OFDM symbols, for a total of 14 OFDM symbols. This format is compatible with the existing 7 symbols per slot, two slots constituting a TTI structure.

For 2-symbol sTTI, three different schemes of single sTTI scheduling, 2 continuous sTTI bundling scheduling and 3 continuous sTTI bundling scheduling can exist in uplink, and the bundling scheduling does not cross the slot boundary of legacy TTI.

For the case of bundled scheduling of different numbers of sTTI, different RS and data configuration schemes may be adopted to schedule the sTTI with the format shown in fig. 1, which is specifically as follows:

if single-sTTI scheduling is adopted, there are two scheduling formats:

scheduling format 1: a DMRS exists in the current sTTI, and the position of the DMRS is the first symbol of the current sTTI;

scheduling format 2: the DMRS does not exist in the current sTTI, and is positioned at the first symbol of the previous adjacent sTTI; with the exception of sTTI0 and sTTI3, the DMRS of which is located at the first symbol of the following adjacent sTTI.

If 2 consecutive sTTI bundled schedules are used, there are the following scheduling formats:

scheduling format 3: the DMRS is located at the last symbol of the first sTTI.

If 3 consecutive sTTI bundled schedules are used, there are the following scheduling formats:

scheduling format 4: the DMRS is located in the first symbol of the second sTTI.

The specific indication scheme is illustrated in fig. 2:

the 4 different scheduling formats may be indicated by using 2 bits, and formats 1 to 4 are indicated by using 11, 00, 10, and 01, respectively. For example: the first indicates the "hopping flag bit" of the bit-multiplexed legacy DCI0, and the second indicates the "resource allocation scheme indication" of the bit-multiplexed legacy DCI0, as shown in table 2:

table 2 scheduling format indication bit allocation scheme

	Frequency hopping flag bit	Resource allocation mode indication
			Scheduling Format
1	1	1
			Scheduling Format 2	0	0
Scheduling Format 3	1	0
			Scheduling Format 4	0	1

The scheduling scheme of the invention combines the service characteristics of the 2-symbol sTTI, fully utilizes the idle bit of legacy DCI0, and completes the data and RS scheduling format indication of the uplink 2-symbol sTTI. On the premise of not increasing signaling overhead, the number and the positions of the RSs are reasonably arranged according to the condition of bundling and scheduling of different numbers of sTTI, the RS overhead is reduced as much as possible, and better channel estimation performance can be ensured.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for transmitting uplink scheduling information of a short transmission time interval (sTTI), comprising:

determining the format of the sTTI;

indicating the scheduling format of the sTTI by using a frequency hopping flag bit and a resource allocation mode indication in a DCI0 (Downlink control information Format) of the traditional TTI;

wherein:

the format of the sTTI is {3,2,2,2,2,3}, wherein the lengths of sTTI0 and sTTI 5 are 3 OFDM symbols, and the lengths of sTTI 1 to sTTI 4 are 2 OFDM symbols;

the bundling scheduling scheme of the sTTI comprises the following steps: single sTTI scheduling, 2 continuous sTTI bundling scheduling, 3 continuous sTTI bundling scheduling;

the scheduling format of the sTTI comprises:

if single-sTTI scheduling is adopted, the scheduling format comprises:

2. The method of claim 1, wherein:

the indicating the scheduling format of the sTTI by using the frequency hopping flag bit and the resource allocation manner in the conventional TTIDCI 0 includes:

and respectively indicating the scheduling formats 1-4 by using different values indicated by the frequency hopping flag bit and the resource allocation mode in the traditional TTIDCI 0.