CN107666373B

CN107666373B - HARQ transmission method and device

Info

Publication number: CN107666373B
Application number: CN201610602806.7A
Authority: CN
Inventors: 钱辰; 喻斌; 熊琦; 付景兴
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2016-07-27
Filing date: 2016-07-27
Publication date: 2022-04-22
Anticipated expiration: 2036-07-27
Also published as: KR20180012706A; KR102398233B1; CN107666373A

Abstract

The application discloses a hybrid automatic repeat request HARQ transmission method, a base station receives a signal sent by a terminal and carries out signal detection, decoding and CRC (cyclic redundancy check); if the CRC passes, determining the identification information of the terminal according to the terminal information carried in the signal, and sending ACK information and the identification information of the terminal; and if the CRC does not pass the CRC check, transmitting NACK information, or not transmitting HARQ information. By applying the method and the device, the problem that the terminal detects the ACK/NACK signal wrongly due to collision can be avoided.

Description

HARQ transmission method and device

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a transmission method and device for hybrid automatic repeat request (HARQ).

Background

With the rapid development of the information industry, especially the growing demand from the mobile internet and internet of things (IoT), the future mobile communication technology is challenged with unprecedented challenges. As can be expected from international telecommunication union ITU's report ITU-R M. [ imt. beyond 2020.TRAFFIC ], by 2020, mobile TRAFFIC will increase by nearly 1000 times in relation to 2010 (era 4G), and the number of user equipment connections will also exceed 170 billion, and will be even more dramatic as the vast number of IoT devices gradually permeates into mobile communication networks. To address this unprecedented challenge, the communications industry and academia have developed an extensive fifth generation mobile communications technology research (5G) facing the 2020. Future 5G frameworks and overall goals are currently discussed in ITU's report ITU-R M [ imt.vision ], wherein the 5G demand landscape, application scenarios and various important performance indicators are specified. For the new requirements in 5G, ITU's report ITU-R M [ imt. user TECHNOLOGY TRENDS ] provides information related to the technical trend for 5G, aiming at solving significant problems of significant improvement of system throughput, consistency of user experience, scalability to support IoT, latency, energy efficiency, cost, network flexibility, support of emerging services, and flexible spectrum utilization.

The requirement of supporting a large-connection-capacity machine-type communication (mtc) service is proposed in 5G, the connection density of the mtc service will reach millions of connections per square kilometer, which is much higher than the link density supported by the existing standard, and the existing Orthogonal Multiple Access method, such as Orthogonal Frequency Division Multiple Access (OFDMA) technology, cannot meet the requirement of the millions of connections required by the mtc service in 5G. To improve the capability of Multiple Access technology, some Non-orthogonal Multiple Access (NoMA) technology is proposed and discussed in 3GPP standards conference as a potential 5G key technology. Among these technologies, Code division Multiple Access (cdma) -based Access methods include Sparse Code Multiple Access (SCMA), Pattern Defined Multiple Access (PDMA), Multi-user Shared Access (MUSA), and the like; and interlace-based Access methods such as Interlace Division Multiple Access (IDMA), and interlace-Grid Multiple Access (IGMA). By using non-orthogonal access resources, such as non-orthogonal codebooks, interleaving sequences and the like, compared with an orthogonal multiple access mode, the access technology can access more users on limited time-frequency resources, so that the equipment connection number in a unit area is remarkably increased, and the requirement in a 5G large-connection-quantity scene is met.

To reduce signaling overhead in large-connection machine communication scenarios, schedule-free transmission will be an important component in 5G research. In the process of Scheduling-free transmission, the original Scheduling Request (SR) of LTE, even the random access process, can be skipped, and when a user has data to transmit, the user directly transmits uplink data using random or system-configured multiple access resources at the specified time-frequency resource. The transmission mode can effectively reduce signaling overhead, but a conflict problem may occur, that is, different users select the same multiple access resource or reference signal for data transmission, thereby causing a reduction in uplink data error performance.

Hybrid Automatic Repeat Request (HARQ) is an important means for ensuring data transmission reliability in LTE. In scheduling-free transmission, HARQ can also be used to improve the reliability of data transmission in resource collisions. Uplink HARQ in LTE-a is transmitted through a Physical HARQ Indicator Channel (PHICH), and the transmission content is an Acknowledgement (ACK) or non-acknowledgement (NACK) indication for uplink data transmission. The HARQ information is indicated by 1-bit data, 0 indicates ACK, and 1 indicates NACK. The 1-bit data is BPSK modulated and repeated three times. Each repeated BPSK symbol is spread with a length-4 Walsh spreading code to obtain length-12 symbol data. The encoding process of the HARQ indication information is shown in fig. 1.

Considering that the number of mutually orthogonal sequences that can be generated by a complex Walsh spreading sequence having a length of 4 is 8, the number of users that can multiplex PHICHs on the same time-frequency resource is 8. In order to reduce inter-cell interference, the symbol sequence with the length of 12 is scrambled based on the cell ID. The PHICH channel occupies 1 to 3 OFDM symbols in the downlink subframe, as shown in fig. 2.

Through the spread spectrum of orthogonal Walsh sequences, a plurality of PHICHs can be multiplexed on the same time frequency resource to form a PHICH group (PHICH group), and different PHICHs are distinguished in the PHICH group through PHICH indexes. In LTE, a PHICH group and a PHICH index are determined by the lowest index of a resource block of a corresponding physical uplink shared channel and cyclic shift of a demodulation reference signal (DMRS). And the user calculates a PHICH group corresponding to the uplink transmission and a PHICH index in the group according to the lowest index of a physical uplink shared channel resource block allocated to the user and the cyclic shift of the used DMRS, thereby determining the physical time-frequency resource of the PHICH and the used spreading code, decoding to obtain ACK/NACK information of the uplink transmission, and simultaneously retransmitting or starting the next uplink data transmission according to the uplink data transmission authorization.

For scheduling-free transmission based on a non-orthogonal multiple access technology, the problem of retransmission indication cannot be well solved by the existing HARQ transmission mode in LTE-A. Firstly, for a large-connection-amount access scene in 5G, because the number of access users carried on the same time-frequency resource is greater than that of a typical scene in LTE-A, ACK/NACK information of more users needs to be multiplexed on the same physical resource block, and a PHICH mapping mode in LTE-A needs to be further enhanced; secondly, for scheduling-free transmission, there may be a case where DMRS and multiple access resources collide, at this time, a transmission mode and a resource mapping mode of HARQ in LTE-a are still used, and a user using the same multiple access resources and DMRS cannot distinguish whether an ACK or NACK signal corresponds to uplink resource transmission of the user, thereby causing a reduction in retransmission efficiency and even a reduction in user data transmission reliability; finally, if there is a resource conflict, the retransmitted received data of different redundancy versions are difficult to combine.

In summary, the HARQ transmission method in LTE-a cannot be well applied to scheduling-free transmission based on the non-orthogonal multiple access technology, and a new solution is needed.

Disclosure of Invention

The application provides a HARQ transmission method and equipment, which can avoid the problem that the terminal detects the error of the ACK/NACK signal caused by collision, and are particularly suitable for scheduling-free transmission based on a non-multiple access technology.

In order to achieve the purpose, the following technical scheme is adopted in the application:

a hybrid automatic repeat request (HARQ) transmission method comprises the following steps:

a base station receives a signal sent by a terminal and performs signal detection, decoding and Cyclic Redundancy Check (CRC);

if the CRC passes, determining the identification information of the terminal according to the terminal information carried in the signal, and sending Acknowledgement (ACK) information and the identification information of the terminal;

and if the CRC does not pass the CRC check, transmitting non-acknowledgement (NACK) information or not transmitting HARQ information.

Preferably, the identifier information of the terminal is carried in an HARQ indicator channel, a downlink control channel, or a downlink shared channel.

Preferably, if the identifier information of the terminal is carried in the HARQ indicator channel, when the NACK information is sent, redundant information having the same length as the identifier information of the terminal is supplemented after the NACK information.

Preferably, the identification information of the terminal is a cell radio network temporary identifier C-RNTI, a temporary mobile subscriber identifier S-TMSI, a terminal identifier generated according to the C-RNTI or the S-TMSI, token information allocated by a base station, or part of uplink data sent by the terminal.

Preferably, the number of bits of the token information is

Wherein

Represents upper rounding, M_maxAllocating the maximum number of terminals with the same uplink transmission resource, wherein the uplink transmission resource comprises a demodulation reference signal DMRS, a multiple access resource and/or a time frequency resource;

and/or randomly generating the identification information of the terminal according to the C-RNTI or the S-TMSI, wherein the bit number of the identification information of the terminal is as follows:

p_N→Ais the probability that a NACK is discriminated as an ACK in the system performance requirements.

Preferably, the randomly generating the identification information of the terminal includes: and generating the identification information of the terminal through a pseudo-random sequence.

Preferably, the generating the identification information of the terminal through the pseudo random sequence includes:

generating an m-sequence by taking a part of bit sequence of C-RNTI or S-TMSI or C-RNTI or S-TMSI as an initial state according to a set generating polynomial for generating the m-sequence; intercepting a part of bits in the generated m-sequence as identification information of the terminal;

alternatively, the first and second electrodes may be,

generating a first m-sequence by taking a C-RNTI or S-TMSI or a partial bit sequence of the C-RNTI or a partial bit sequence of the S-TMSI as an initial state according to a set generating polynomial for generating the first m-sequence; generating a Gold sequence according to the first m-sequence and a set second m-sequence, and intercepting part of bits in the generated Gold sequence as identification information of the terminal;

or generating the first m-sequence by taking the C-RNTI or the S-TMSI or a part of bit sequence of the C-RNTI or a part of bit sequence of the S-TMSI as an initial state according to a set generating polynomial for generating the first m-sequence; generating a second m-sequence by taking a part of bit sequence of C-RNTI or S-TMSI or C-RNTI or S-TMSI as an initial state according to a set generating polynomial for generating the second m-sequence; generating a Gold sequence according to the first m-sequence and a set second m-sequence, and intercepting part of bits in the generated Gold sequence as the identification information of the terminal.

Preferably, before performing said signal detection, the method comprises: performing DMRS collision detection;

when the collision detection result of the DMRS is collision, if the signal does not pass the CRC check, the method comprises the following steps: the base station clears the cache of the corresponding signal and sends a conflict indication or a new transmission indication; when the collision detection result of the DMRS is non-collision, if the signal does not pass the CRC check, the method comprises the following steps: and the base station stores the detection result in a buffer memory of a corresponding signal and sends a non-conflict indication or a retransmission indication.

Preferably, before receiving the uplink signal sent by the terminal, the method includes:

the base station configures DMRS and multiple access resources for the terminal through signaling of a downlink control channel or system high-level signaling, and the DMRS and the multiple access resources are used for uplink signal transmission of the terminal;

or, the base station configures a resource pool for the terminal, for uplink signal transmission of the terminal; wherein the resource pool comprises DMRS, multiple access resources and/or time frequency resources.

Preferably, the base station determines the DMRS and multiple access resources configured for the terminal according to the monitored network load condition.

Preferably, the determining DMRS and multiple access resources configured for the terminal includes:

when the network load exceeds a set threshold value, the base station increases the number of terminals configured with the same multiple access resource and/or DMRS;

and/or determining the DMRS and the multiple access resource configured for the terminal according to the network load condition and the corresponding multiple access resource and/or the DMRS with the same configuration according to a preset lookup table.

Preferably, before sending the ACK information or the NACK information, the method includes: determining a time-frequency resource of an HARQ indication channel corresponding to the signal according to a time-frequency resource position for bearing the signal, a multiple access resource used by the signal and the DMRS characteristic of the signal;

and sending the ACK information or NACK information on the determined time-frequency resource of the HARQ indication channel.

Preferably, the time frequency resource of the HARQ indicator channel is formed by an index group

Determining time-frequency resources; wherein the content of the first and second substances,

a channel group index is indicated for the HARQ,

for intra-group sequence indexing, said index group

The method is determined according to the time-frequency resource position for bearing the signal, the multiple access resource used by the signal and the DMRS characteristic of the signal.

Preferably, the index set is determined when there is no mapping relationship between the DMRS and the multiple access resource or when there is a one-to-many mapping relationship between the DMRS and the multiple access resource

The method comprises the following steps:

alternatively, the first and second electrodes may be,

wherein, I_{PRB_RA}For the index of the time-frequency resource carrying said signal, N is the mapping relation between DMRS and multiple access resource_MA' is at I_{PRB_RA}The total number of available multiple access resources on the corresponding time frequency resource, N is when there is a one-to-many mapping relation between DMRS and multiple access resources_MA' is the total number of multiple access resources having a mapping relation with the same DMRS, n_MA' multiple access resources used for the signal are in N_MA' index in multiple Access resources, N_DMRSIs at I_{PRB_RA}Number of DMRS available on corresponding time-frequency resources, n_DMRSDMRS used for the signal at N_DMRSThe DMRS index in each of the DMRSs,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

determining an index group when there is a many-to-one mapping relationship between a DMRS and a multiple access resource

The method comprises the following steps:

alternatively, the first and second electrodes may be,

wherein, I_{PRB_RA}For the index of the time-frequency resource carrying the signal, N_MAIs at I_{PRB_RA}Total number of available multiple access resources, n, on corresponding time-frequency resources_MAMultiple access resources used for said signal are in N_MAIndex in multiple access resources, N_DMRS' number of available DMRSs corresponding to multiple access resources used for the signal, n_DMRS' DMRS used for the signal is at N_DMRS' an index in the number of DMRSs,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

determining an index group when there is a one-to-one mapping relationship between a DMRS and a multiple access resource

The method comprises the following steps:

alternatively, the first and second electrodes may be,

wherein, I_{PRB_RA}For the index of the time-frequency resource carrying the signal, N_MAIs at I_{PRB_RA}Total number of available multiple access resources, n, on corresponding time-frequency resources_MAMultiple access resources used for said signal are in N_MAIndex in multiple access resources, N_DMRSIs at I_{PRB_RA}Number of DMRS available on corresponding time-frequency resources, n_DMRSDMRS used for the signal at N_DMRSThe DMRS index in each of the DMRSs,

the number of channel groups is indicated for HARQ.

Preferably, the performing signal detection includes:

and the base station carries out DMRS activation detection according to the signal and carries out the detection of the signal by using the multiple access resource corresponding to the DMRS which is judged to be activated.

Preferably, the DMRS activation detection includes: and performing correlation energy detection on all possible DMRSs, and judging that the DMRS of which the detection result is higher than a set energy detection threshold is activated.

Preferably, if the signal is determined to be retransmitted data according to the result of the signal detection, after the signal is detected and before the signal is decoded, the method includes: and determining the previous transmission data corresponding to the retransmission data by utilizing the mapping relation between the new transmission resource pool and each retransmission resource pool according to the multiple access resource corresponding to the activated DMRS, and merging and decoding during the decoding processing.

Preferably, for the DMRS determined to be inactive, the base station does not transmit information on all HARQ indicator channels corresponding to the inactive DMRS, or the base station transmits NACK information on all HARQ indicator channels corresponding to the inactive DMRS;

or, if the DMRS determined to be activated does not pass the CRC check, the base station transmits NACK information on all HARQ indication channels corresponding to the activated DMRS and sends a retransmission indication; and for the DMRS which is determined to be inactive, the base station transmits NACK information on all HARQ indication channels corresponding to the inactive DMRS and transmits a new transmission indication.

a first terminal sends an uplink signal to a base station;

the first terminal receives HARQ information corresponding to the uplink signal on a time-frequency resource of an HARQ indication channel;

when the received HARQ information is ACK information, the first terminal extracts the identification information of the terminal corresponding to the HARQ information from the information sent by the base station; if the identification information is consistent with the identification information of the first terminal, determining that the uplink signal is correctly received; if the identification information is inconsistent with the identification information of the first terminal, terminating the transmission and retransmitting the uplink signal for the first time;

and when the received HARQ information is NACK information, retransmitting the uplink signal or retransmitting the uplink signal for the first time.

Preferably, the determining that the uplink signal is correctly received includes: sending ACK information to an upper layer, and finishing the transmission;

and/or the presence of a gas in the gas,

the retransmitting the uplink signal for the first time includes: and transmitting the NACK information and the new transmission request to an upper layer.

Preferably, when the first terminal does not receive the HARQ information on the time-frequency resource of the HARQ indication channel, the first terminal determines that the HARQ indication information is NACK information.

Preferably, when the received HARQ information is NACK information, the retransmitting or retransmitting the uplink signal for the first time includes: detecting a conflict indication or a retransmission/new transmission indication, and if the conflict indication is not conflict or the retransmission/new transmission indication is a retransmission indication, sending NACK information and a retransmission request to an upper layer until the maximum transmission times are reached; if the conflict indication is a conflict or the retransmission/new transmission indication is a new transmission indication, sending NACK information and a new transmission request to an upper layer for indicating the upper layer to perform the first transmission on the uplink signal again;

or, when the HARQ information is NACK information, the retransmitting or retransmitting the uplink signal for the first time includes: NACK information is transmitted to the upper layer.

Preferably, the HARQ _ RE in the HARQ process corresponding to the uplink signal is used to carry the retransmission request or the new transmission request.

Preferably, the sending, by the first terminal, the uplink signal to the base station includes:

when new transmission data exists, an HARQ entity in the first terminal establishes a corresponding HARQ process for the new transmission data, allocates time-frequency resources, DMRS and multiple-access resources for the HARQ process, and sends the allocated resources and the new transmission data to the HARQ process, wherein the allocated time-frequency resources, DMRS and multiple-access resources are saved in the HARQ process;

in each transmission time interval TTI, for each time-frequency resource used for scheduling-free transmission, the HARQ entity determines the HARQ process corresponding to the time-frequency resource, and sends the received HARQ information or new transmission data corresponding to the HARQ process to the corresponding HARQ process and indicates the corresponding HARQ process to perform retransmission or new transmission; the DMRS and the multiple access resources stored in the HARQ process are used for distinguishing whether HARQ information sent to the HARQ process by an HARQ entity belongs to the HARQ process, and the HARQ entity is used for maintaining a plurality of parallel HARQ processes;

preferably, the allocating time-frequency resources, DMRS, and multiple access resources for the HARQ process includes: determining DMRS and multiple access resources allocated to the first terminal according to a command in a downlink control channel or configuration of a system high-level signaling, using the DMRS and multiple access resources as DMRS and multiple access resources for transmitting the uplink signal, and randomly selecting time frequency resources from available time frequency resources of a time frequency resource pool set by a base station for the first terminal; or randomly selecting multiple access resources and DMRS with equal probability from available resources of a resource pool configured by a base station for the first terminal, and randomly selecting time-frequency resources from the available resources of the configured resource pool;

and/or the presence of a gas in the gas,

the HARQ entity sending HARQ information or newly transmitted data to the HARQ process and instructing the corresponding HARQ process to perform retransmission or new transmission includes: determining that each time-frequency resource belongs to a new transmission time-frequency resource or a retransmission time-frequency resource of the HARQ process according to the mapping relation between the new transmission resource and the retransmission resource, if the time-frequency resource is determined to belong to the retransmission time-frequency resource, selecting the retransmission resource for the corresponding HARQ process according to the mapping relation, sending the selected resource and the HARQ information to the HARQ process, and indicating the corresponding HARQ process to initiate retransmission; and if determining that each time-frequency resource belongs to a newly transmitted time-frequency resource of the HARQ process, transmitting the newly transmitted data to the HARQ process, and indicating the HARQ process to initiate new transmission by using the stored resources.

Preferably, the selecting the retransmission resource for the HARQ process according to the mapping relationship includes: selecting a retransmission time-frequency resource for the HARQ process according to the mapping relation; when the HARQ process initiates data retransmission, the stored DMRS and multiple access resources and the received retransmitted time-frequency resources are utilized to carry out the HARQ process;

or, the selecting the retransmission resource for the HARQ process according to the mapping relationship includes: selecting a time-frequency resource, a DMRS (demodulation reference signal) and a multiple-access resource for the HARQ process according to the mapping relation; and when the HARQ process initiates data retransmission, the data retransmission is carried out by utilizing the received retransmitted time-frequency resource, the DMRS and the multiple-access resource.

Preferably, the available resources are time-frequency resources, DMRS and multiple-access resources which are not used for new transmission and retransmission of data by the HARQ entity;

and/or the available time frequency resource is a time frequency resource which is not used for the new transmission and retransmission of the data by the HARQ entity.

Preferably, when the retransmission indication received by the HARQ entity indicates that retransmission is not required or the number of retransmissions reaches the maximum, the HARQ entity takes out the data in the data buffer from the corresponding HARQ process, releases the resource allocated to the HARQ process, and resets the HARQ process.

Preferably, the determining the time-frequency resource of the HARQ indicator channel includes: and determining the time-frequency resource of the HARQ indication channel corresponding to the signal according to the time-frequency resource position for bearing the signal, the multiple access resource used by the signal and the DMRS characteristic of the signal.

a channel group index is indicated for the HARQ,

for intra-group sequence indexing, said index group

The method comprises the following steps:

alternatively, the first and second electrodes may be,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

The method comprises the following steps:

alternatively, the first and second electrodes may be,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

The method comprises the following steps:

alternatively, the first and second electrodes may be,

wherein, I_{PRB_RA}For carrying theIndex of time-frequency resource of signal, N_MAIs at I_{PRB_RA}Total number of available multiple access resources, n, on corresponding time-frequency resources_MAMultiple access resources used for said signal are in N_MAIndex in multiple access resources, N_DMRSIs at I_{PRB_RA}Number of DMRS available on corresponding time-frequency resources, n_DMRSDMRS used for the signal at N_DMRSThe DMRS index in each of the DMRSs,

the number of channel groups is indicated for HARQ.

A hybrid automatic repeat request, HARQ, transmission apparatus, comprising: a signal detection unit and a transmission unit;

the signal detection unit is used for receiving the signal sent by the terminal and carrying out signal detection, decoding and CRC (cyclic redundancy check);

the sending unit is configured to determine, according to terminal information carried in the signal, identification information of the terminal when the signal detection unit determines that the CRC check is passed, and send acknowledgement ACK information and the identification information of the terminal; and is further configured to transmit non-acknowledgement, NACK, information or not transmit HARQ information when the signal detection unit determines that the CRC check is not passed.

A hybrid automatic repeat request, HARQ, transmission apparatus, comprising: a transmitting unit and a receiving unit;

the transmitting unit is used for transmitting an uplink signal to a base station;

the receiving unit is configured to receive HARQ information of the uplink signal on a time-frequency resource of an HARQ indicator channel; when the received HARQ information is ACK information, extracting identification information of a terminal corresponding to the HARQ information from information sent by a base station; if the identification information is consistent with the identification information of the terminal, determining that the uplink signal is correctly received; if the identification information is not consistent with the identification information of the terminal, the transmission is stopped, and the uplink signal is transmitted again for the first time; and when the received HARQ information is NACK information, retransmitting the uplink signal or retransmitting the uplink signal for the first time.

According to the technical scheme, the base station also sends the identification information of the terminal when sending the ACK information; after receiving the ACK information, the terminal extracts the identification information of the terminal; if the extracted identification information is consistent with the identification information of the terminal, the data is determined to be correctly received, otherwise, the uplink signal sent last time is transmitted again for the first time. By the method, the terminal ID information is transmitted while the ACK signal is transmitted, so that the problem that the terminal detects the ACK/NACK signal incorrectly due to collision can be avoided; in addition, the terminal directly initiates new transmission after receiving the ACK signal and finding that the ID information of the terminal is not matched, so that the problem that the reliability of data transmission cannot be improved by retransmission under the condition is solved.

In addition, preferably, when the base station and the terminal determine the position of the HARQ indication channel, the base station and the terminal perform the determination according to the time-frequency resource position for carrying the uplink signal, the multiple access resource used by the uplink signal, and the DMRS characteristic of the uplink signal; compared with the current mode determined according to the lowest index of the uplink resource block and the cyclic shift of the used DMRS, the method can correspond to the positions of more HARQ indication channels for the same uplink physical resource block, so that more users can be multiplexed on the same physical resource block.

Drawings

Fig. 1 is a schematic diagram of an HARQ indication information encoding process;

FIG. 2 is a diagram illustrating a conventional PHICH time-frequency resource mapping scheme;

FIG. 3 is a mapping relationship between a new transmission resource pool and a retransmission resource pool;

fig. 4 is a diagram illustrating a possible uplink data structure;

fig. 5 is a flowchart illustrating an HARQ transmission method according to the present application;

fig. 6 is a diagram of HARQ indicator channel information bits;

fig. 7 is a flow of HARQ indicator channel information processing;

FIG. 8a is a schematic diagram of a distribution formula of time-frequency resource indexes;

FIG. 8b is a diagram illustrating another allocation of time-frequency resource indexes;

FIG. 9 is a schematic diagram of a possible token bit allocation;

FIG. 10 is a schematic diagram of the manner in which an m-sequence is used to determine a terminal identity;

FIG. 11 is a diagram of terminal identifier generation using Gold sequences;

FIG. 12 is a schematic illustration of a collision detection threshold;

FIG. 13 is a schematic diagram of one possible terminal-side behavior;

FIG. 14 is a schematic view of another terminal-side behavior;

fig. 15 is a block diagram of a preferred HARQ transmission apparatus according to the present application;

fig. 16 is a schematic diagram of a structure of another HARQ transmission apparatus according to another preferred embodiment of the present invention.

Detailed Description

For the purpose of making the objects, technical means and advantages of the present application more apparent, the present application will be described in further detail with reference to the accompanying drawings.

As described in the background, the current HARQ transmission method has many problems for scheduling-free transmission based on the non-orthogonal multiple access technique. Based on this, the present application provides an HARQ transmission method, which enables more users to multiplex on the same uplink physical resource block. The HARQ transmission method is suitable for various existing transmission scenes, such as LTE, LTE-A and the like, is also suitable for access scenes with larger connection capacity, such as 5G scenes, and is particularly suitable for scheduling-free transmission based on a non-multiple access technology. The following describes the HARQ transmission method in the present application by taking a scheduling-free transmission scenario as an example, but the processing in the present application is not limited to this transmission scenario.

First, the schedule-free transmission is explained. According to the allocation and selection of resources, scheduling-free transmission can be classified into the following two categories:

1. the base station configures the multiple access resource and/or DMRS and/or time frequency resource of the terminal through the signaling in the downlink control channel or the system high-level signaling, and the terminal directly transmits the configured multiple access resource, DMRS and/or time frequency resource when having the data transmission requirement without requesting the uplink authorization.

Preferably, the base station may configure a multiple access resource and a DMRS for the terminal through signaling, and set a time-frequency resource for scheduling-free transmission, when the terminal has data transmission, select a scheduling-free time-frequency resource for the current transmission from the set time-frequency resources, and transmit the data using the configured multiple access resource and the DMRS on the selected time-frequency resource.

In this way, the terminal has completed uplink synchronization and access through processes such as random access, and obtains information such as terminal ID, and is in an RRC connected state. After finishing uplink synchronization and access, the base station allocates multiple access resources and/or DMRS for the terminal through signaling in a downlink control channel or system high-level signaling. The base station may allocate the same multiple access resources and/or DMRS to different terminals. After the resource allocation is completed, the terminal continuously uses the allocated multiple access resource and the DMRS to transmit uplink data on the designated time-frequency resource. If the terminal completes the transmission of the uplink data and is separated from the RRC connection state to enter an idle state, the terminal informs the base station through an uplink control channel or an uplink shared channel, and the base station releases the multiple access resources and the DMRS allocated to the base station.

The base station can also allocate periodic time-frequency resources for the terminal, and when the terminal has data to send, that is, when data is transmitted for the first time, the terminal randomly selects from the time-frequency resources allocated by the base station and sends the data. For the retransmission of data, the time-frequency resources allocated to the terminal can be divided into new transmission time-frequency resources and retransmission time-frequency resources, a mapping relation between the new transmission time-frequency resources and the retransmission time-frequency resources is established, and when the retransmission time-frequency resources are allocated, the time-frequency resources of the retransmission are selected from the time-frequency resources allocated by the base station according to the mapping relation.

The base station continuously monitors the network load condition, and for the DMRS and the multiple access resources configured to the terminal by the base station, the base station can adjust the allocation of the multiple access resources and the allocation of the DMRS according to the monitored network load condition. For example, if the base station finds that the network load becomes heavy, the same multiple access resource and DMRS may be allocated to more users; if the base station finds that the network load becomes light, the same multiple access resource and DMRS can be allocated to fewer users. That is, preferably, the heavier the network load, the more terminals may be allocated the same multiple access resource and/or DMRS. The base station can change the multiple access resources and the DMRS allocated to the terminal according to the change of the network load condition, and inform the change condition of the resources allocated to the terminal through a downlink control channel or a high-level signaling; the terminal monitors a downlink control channel or a high-level signaling notification, releases the original resources when the allocated resources change, and adopts new resources for transmission.

In this way, the base station can control the probability of terminal collision and adjust the probability of terminal collision according to the network load condition. Preferably, when the network load exceeds a set threshold, the base station may increase the number of terminals configured with the same multiple access resource and/or DMRS; and determining the DMRS and the multiple access resource configured for the terminal according to the network load condition and the corresponding multiple access resource and/or DMRS with the same configuration according to a preset lookup table. For example, if the network load is heavy, the probability of terminal collision can be increased through resource allocation, so as to ensure the number of terminals supported; if the network load is lighter, the probability of terminal collision can be reduced through resource allocation, and the data transmission quality of the load in the network is ensured.

2. The base station allocates a resource pool for scheduling-free transmission. The resource pool comprises multiple access resources, DMRS and time frequency resources. When the terminal needs to send data, multiple access resources and DMRS are randomly selected from the resource pool at equal probability, and time-frequency resources are randomly selected to send uplink data.

In this case, the base station configures a resource pool for the terminal without scheduling transmission, and notifies the terminal through system information in a broadcast channel and a downlink control channel, or through a high-level signaling. The resources in the resource pool include, but are not limited to, time-frequency resources, multiple access resources, and DMRS resources. When the terminal transmits uplink data, the terminal randomly selects uplink transmission resources (including time-frequency resources, multiple access resources and DMRS) in a resource pool configured by the base station according to equal probability, processes the uplink transmission data according to the selected multiple access resources on the selected time-frequency resources, inserts the selected DMRS and transmits the uplink data. This method is suitable for the terminal in idle state or in RRC connected state after completing the uplink access. That is, no matter whether the terminal completes uplink access or not, the terminal can transmit uplink data as long as it completes downlink synchronization and acquires a part of system information.

In order to distinguish the newly transmitted data from the retransmitted data and establish a relationship between the newly transmitted data and the retransmitted data, a resource pool for the newly transmitted data and a resource pool for the retransmitted data may be separated, and a mapping relationship is established between corresponding resources, as shown in fig. 3.

In FIG. 3, the resource pool is divided into N_maxAnd the mutually disjoint sub-resource pools are respectively used for newly transmitted data and data retransmitted each time. Wherein N is_maxIs the maximum number of transmissions. And mapping relation exists among the resources in each resource pool. In the example shown in fig. 3, the number of resources in the resource pool for each transmission is the same, a one-to-one mapping relationship exists between the resources in the resource pool for each transmission, and if the terminal selects a resource k in a new resource pool when data is transmitted for the first time, the terminal selects a corresponding resource k' having a one-to-one mapping relationship with the resource k in a corresponding retransmission resource pool if retransmission is required. The resources comprise multiple access resources, DMRS and/or time frequency resources.

When the mapping manner between the resource pools of the newly transmitted data and the retransmitted data is not limited to the one-to-one mapping manner shown in fig. 3, for example, the resource pools may be mapped one-to-many or mapped many-to-many, and the new transmission resources and the retransmission resources of the user can also be divided, but it is required to ensure that the retransmission resources of the nth retransmission can find the only corresponding resources of the previous transmission.

For scheduling-free transmission, the base station does not send uplink grant to the terminal, and does not allocate time-frequency resources for uplink transmission, so that it is impossible to implement the source of uplink data on the allocated time-frequency resource region by using grant similar to that in LTE-a. In order to facilitate the base station to determine the source of the uplink data, the terminal may attach terminal ID information to the data while transmitting the uplink data. One possible scheduling-free upstream transmission data structure is shown in fig. 4.

In fig. 4, terminal Identification (ID) information is inserted before uplink data. The terminal ID information may be inserted after the uplink data or in the middle of the uplink data. If the detected and decoded uplink data passes the CRC check, the base station can know from which terminal the uplink data originated through the terminal ID information.

In addition, a mapping relationship may or may not exist between the DMRS and the multiple access resource in the system. If a mapping relation exists between the DMRS and the multiple access resource, the selection range of the multiple access resource can be determined through the selection of the DMRS. For example, there is a one-to-one mapping relationship between DMRS and multiple access resources, that is, selecting DMRS is equivalent to selecting corresponding multiple access resources, and the base station can also know the usage of multiple access resources through detection of DMRS. A many-to-one mapping relation exists between the DMRS and the multiple access resources, namely different DMRSs can be mapped to the same multiple access resources, and at the moment, the base station can also know the use condition of the multiple access resources through the detection of the DMRS. This approach is mostly used for scenarios where there are more DMRS resources and more multiple access resources. There is a one-to-many mapping relationship between DMRSs and multiple access resources, that is, the same DMRSs may be mapped to different multiple access resources, and at this time, the base station can know the range of the multiple access resources through detection of the DMRSs. This approach is mostly used for scenarios with more multiple access resources and more DMRSs than others.

Next, a transmission method of HARQ provided in the present application is described. The HARQ transmission method in the present application includes two types, one is a process on the base station side, and the other is a process on the terminal side, and for convenience of description, the following description is made by combining processes on the base station side and the terminal side together. Fig. 5 is a basic flowchart of an HARQ transmission method including base station side and terminal side processing in the present application. As shown in fig. 5, the basic flow is as follows:

step 501, the terminal sends an uplink signal to the base station.

In this step, the terminal may transmit the uplink signal in the foregoing scheduling-free transmission manner. Specifically, multiple access resources and/or DMRSs can be randomly selected with equal probability according to a resource pool configured by a base station; or, the terminal may also perform uplink data transmission according to a multiple access resource and/or DMRS configured by the base station through signaling in the downlink control channel or system high-level signaling. The transmitted uplink data includes terminal ID information.

Step 502, the base station receives the uplink signal, and performs signal detection, decoding, and CRC check.

Step 503, if the CRC check is passed, the base station determines the identifier information of the terminal according to the terminal information carried in the uplink signal, and sends the ACK information and the identifier information of the terminal on the time-frequency resource of the HARQ indication channel corresponding to the uplink signal.

In the present application, it is determined that data reception is correct after passing CRC check, and considering that different terminals use the same uplink resource, when ACK information is fed back, Identification (ID) information of the terminal is fed back to the terminal together. The identification information of the terminal may be determined according to the terminal information carried by the uplink signal.

Step 504, if the CRC check fails, NACK information is sent on the time-frequency resource of the HARQ indicator channel corresponding to the uplink signal, or HARQ information is not transmitted.

In step 505, the terminal receives HARQ information corresponding to the uplink signal on the time-frequency resource of the HARQ indication channel, and performs step 506 when the received information is ACK information, and performs step 507 when the received information is NACK information.

Step 506, the terminal extracts the identification information of the terminal corresponding to the HARQ information from the information sent by the base station; if the identification information is consistent with the identification information of the terminal, determining that the uplink signal is correctly received; otherwise, terminating the transmission and retransmitting the uplink signal for the first time.

When the transmission mode is scheduling-free transmission, if the terminal detects ACK, and the terminal ID information carried by the uplink or downlink control channel or the downlink shared channel of the time-frequency resource is matched with the terminal ID information, the base station correctly receives the uplink data information, and the current uplink data transmission is correctly completed; if the ACK is detected, and at the same time, the terminal ID information carried by the uplink or downlink control channel or downlink shared channel of the time-frequency resource is not matched with the terminal ID information, which indicates that the resource or DMRS collision occurs in the uplink data transmission, and the terminal reselects the uplink resource (which may be reselecting the multiple access resource, DMRS, and time-frequency resource, or may only reselect the time-frequency resource) to initiate the transmission of the uplink data (i.e., reselecting the first transmission of the uplink data).

In step 507, the terminal retransmits or retransmits the uplink signal for the first time.

If the terminal detects NACK, the terminal may use an existing processing manner, i.e., use a new Redundancy Version (RV), retransmit using a designated multiple access resource and DMRS, and count the number of retransmissions. And if the retransmission times are greater than the maximum retransmission times set by the system, the uplink transmission fails, the terminal returns the retransmission times to zero, reselects the multiple access resource and the DMRS and reinitiates the transmission of the uplink data.

So far, the most basic HARQ transmission flow in the present application shown in fig. 5 ends. Wherein, step 501, step 505, step 506, and step 507 constitute the HARQ transmission method at the terminal side in the present application, and step 502, step 503, and step 504 constitute the HARQ transmission method at the base station side in the present application. By the basic HARQ transmission method, when a plurality of terminals share the same uplink resource for scheduling-free transmission, the terminals corresponding to the ACK information can still be distinguished, and the retransmission efficiency and the reliability of user data transmission are improved.

On the basis of the most basic transmission method shown in fig. 5, the base station and the terminal may further include the following processing:

1. before sending the ACK information or the NACK information, the base station determines the position of an HARQ indicating channel corresponding to the uplink signal according to the time-frequency resource position of the uplink signal, the multiple access resource used by the uplink signal and the DMRS characteristic, and sends the ACK information or the NACK information determined according to the CRC check result at the determined position.

In the application, the position of the HARQ indication channel is determined according to the time-frequency resource position for bearing the uplink signal, the multiple access resource used by the uplink signal and the DMRS characteristic. Compared with the existing mode of determining the PHICH position according to the index of the time-frequency resource and the DMRS cyclic shift, the mode in the application can provide more combinations to determine the position of the HARQ indication channel, particularly more combinations of multiple access resources and the DMRS can be provided corresponding to the same time-frequency resource, so that more users can be corresponding to the same uplink physical resource, and the same uplink physical resource can be multiplexed by the more users.

2. When the terminal determines the position of the HARQ indicating channel, the position of the HARQ indicating channel corresponding to the uplink signal is determined according to the time-frequency resource position of the uplink signal, the multiple access resource used by the uplink signal and the DMRS characteristic, and HARQ (ACK/NACK) information is detected on the determined position of the HARQ indicating channel. The method for determining the HARQ indicator channel position by the terminal is the same as that of the base station, and is not described herein again.

The scheme provided by the invention is specifically described by the specific examples.

Example one

In this embodiment, a resource mapping method based on the HARQ transmission scheme of the present invention will be described, which specifically corresponds to the manner in which the base station and the terminal side determine the HARQ indicator channel. For the non-scheduling transmission scheme based on non-Orthogonal multiple access, the time-frequency resource position of the HARQ indicator channel is determined by the uplink transmission time-frequency resource position, the DMRS characteristics used for uplink transmission (e.g., DMRS cyclic shift, Orthogonal code (OCC) used for DMRS, comb structure used for DMRS, etc.), and the multiple access resources (e.g., interleaving sequence or codebook, etc.) used for uplink transmission.

First, the transmission of HARQ information on the HARQ indication channel will be described. In this application, if the transmission mode is scheduling-free transmission, the HARQ indicator channel transmission content may include: 1-bit ACK information + terminal ID information, or 1-bit ACK information, or 1-bit NACK information.

The terminal ID information may be a 16-bit Cell radio network temporary identifier (C-RNTI) allocated by the base station to the terminal; or a 48-bit temporary mobile subscriber identity (S-TMSI) unique to the terminal; or a terminal special identifier with shorter length is generated according to the C-RNTI or the S-TMSI; or Token bits (Token) allocated by the base station to the terminal; or a part of the uplink data (e.g., part or all of the CRC check bits) transmitted by the terminal.

When the terminal ID information is transmitted together with the ACK information in the HARQ indicator channel, in order to ensure that the lengths of the HARQ indicator channel when the ACK signal is transmitted and the NACK signal is transmitted are the same, the 1-bit NACK signal may be supplemented with redundant information having the same length as the terminal ID information, where the redundant information may be an all-zero sequence or a repetition of the NACK signal, as shown in fig. 6.

The terminal ID information may also be transmitted through another transmission method, specifically, only 1-bit ACK/NACK information is transmitted in the HARQ indication channel, and the terminal ID information is transmitted in a downlink control channel or a downlink shared channel. At this time, the information bits in the HARQ indication channel have only 1 bit.

After obtaining the information bit of the HARQ indication channel, the information bit sequence is modulated in constellation, the modulated symbol is coded repeatedly, and then the spreading factor is carried out

And resource mapping is performed on the symbol stream, as shown in fig. 7.

In order to ensure the reliability of HARQ indicator channel detection, the constellation modulation adopts low-order modulation, such as BPSK or QPSK modulation; the spreading is performed by using orthogonal sequences, e.g. the spreading codes are orthogonal complex Walsh sequences with a length of

Can generate

The present embodiment assumes that subsequent operations are spread using orthogonal complex Walsh sequences. The HARQ indication channels multiplexed on the same time frequency resource form a HARQ indication channel group, and the group is distinguished by the indexes of orthogonal sequences. Different HARQ indication channel groups are distinguished from each other by time-frequency resources. The number of HARQ groups transmitted on the same downlink subframe is

The value is determined according to the number of resources allocated by the downlink control channel and the number of resources occupied by the HARQ indication channel. In addition, the number of groups is determined

The number of the compounds to be combined

When necessary, it is necessary to ensure the product thereof

The same as the number of resources available on the scheduling free resources mapped to the subframe.

The following describes a resource allocation process of the HARQ indicator channel, that is, a process for determining the HARQ indicator channel position by the base station and the terminal side.

For uplink transmission data transmitted on subframe n, the terminal should transmit on subframe n + k_PHICHAnd determining a corresponding HARQ indication channel. Wherein the parameter k_PHICHTaking different values according to different frame structures. For example, for Frequency Division Duplex (FDD) mode, k_PHICHIs a fixed value, e.g. k_PHICH4; for Time Division Duplex (TDD) mode, k_PHICHDetermined by different uplink/downlink configurations. For example, for uplink/downlink configuration in LTE-a, the following configuration may be adopted:

table 1: k in TDD mode_PHICHValue taking

In the above table, the positions with numbers represent uplink transmission symbols, and the positions without numbers represent downlink transmission symbols or special time slots.

For autonomous TDD frame structure (Self-contained TDD frame structure) that 5G may employ, k_PHICHDepending on the symbol length (i.e., subcarrier spacing) and base station processing capability, k may be taken_PHICHA positive integer.

Time-frequency resource of HARQ indication channel is composed of index group

Determining, wherein,

a channel group index is indicated for the HARQ,

is indexed for intra-group sequences. The index group is determined jointly according to the selected time-frequency resource, the selected DMRS and the selected multiple access resource when the terminal sends the uplink data. The manner of determining the index group is different according to the selection manner. Possible ways are listed below:

first, when there is no mapping relationship between the DMRS and the multiple access resource, or there is a one-to-many mapping relationship between the DMRS and the multiple access resource (i.e., one DMRS corresponds to multiple access resources), an index set is used

The determination of (2) is as follows:

alternatively, the first and second electrodes may be,

wherein, I_{PRB_RA}A time-frequency resource index selected when the terminal transmits uplink data,

the number of channel groups is indicated for HARQ. Fig. 8a and 8b show possible time-frequency resource index allocation manners.

Fig. 8a and 8b show several possible allocation manners of the time-frequency resource index according to the time-frequency resource allocation manner allocated to the scheduling-free transmission terminal. In fig. 8a and 8b, the time-frequency resources allocated for scheduling-free transmission are distributed discretely over the whole frequency band, and fig. 8a and 8b only show the resources allocated for scheduling-free transmission, which are referred to herein as scheduling-free resource sub-blocks. A time frequency resource selection mode is that after a terminal selects a certain scheduling-free resource sub-block, the terminal will occupy the time frequency resource for data transmission; multiple terminals may select the same resource sub-block for transmission of data. In fig. 8a, the time-frequency resource index is divided in a frequency division manner, and the scheduling-free resource sub-blocks located in the same time slot are numbered according to frequency and used as the time-frequency resource index. For example, the scheduling-free resource sub-blocks are sorted according to the frequency size order, the index of the scheduling-free resource sub-block with the lowest frequency is set to 0, and the scheduling-free resource sub-blocks are numbered in sequence, as shown in fig. 8 a. In fig. 8b, the scheduling-free resource sub-blocks are numbered according to the frequency and the sub-frame number, and are used as the time-frequency resource index. For example, the index of the non-scheduling resource block with the lowest frequency and the lowest subframe number is set to 0, and the non-scheduling resource sub-block is numbered according to frequency and time, as shown in fig. 8 b. The number is the index of the scheduling-free resource sub-block.

The above method for confirming the scheduling-free resource is also applicable to the case where a plurality of scheduling-free resource blocks are continuous in time or frequency, and is not described herein again.

For DMRS and multiple access resourcesIn the case of no mapping between sources, parameter N_MAIs indexed by I_{PRB_RA}The number of available multiple access resources on the time frequency resource; parameter N for the case where there is a one-to-many mapping relationship between DMRS and multiple access resources_MA' is the number of multiple access resources having a mapping relation with the same DMRS. Parameter n_MAIs' N_MA' the index of the multiple access resource selected by the uplink data in the multiple access resources is configured by the high layer and is informed to the terminal through the downlink control channel or the shared channel.

Parameter N_DMRSAs an index of I_{PRB_RA}The number of DMRSs available on the time-frequency resources of (a). Parameter n_DMRSIs N_DMRSAnd the index of the DMRS selected by the uplink data in the DMRS is configured by a high layer and is informed to the terminal through a downlink control channel or a shared channel. Considering that different DMRSs can multiplex the same time-frequency resource through cyclic shift, orthogonal cover codes and comb tooth structures, a parameter N for representing the number of the DMRSs_DMRSAnd n_DMRSCan be expressed as follows:

N_DMRS＝N_CSN_OCCN_comb

n_DMRS＝n_CSN_OCCN_comb+n_OCCN_comb+n_comb

wherein N is_CS，N_OCC，N_combRespectively representing the available cyclic shift quantity, the orthogonal cover code quantity and the comb tooth structure quantity; n is_CSIs a cyclic shift index; n is_OCCIs an orthogonal cover code index; n is_combIndexed for comb structure. The corresponding index definition mode is formed by the agreement of a base station and a terminal.

Second, when there is a many-to-one mapping relationship between DMRSs and multiple access resources (i.e. one multiple access resource corresponds to multiple DMRSs), an index set is used

The determination of (2) is as follows:

alternatively, the first and second electrodes may be,

wherein, I_{PRB_RA}And selecting the time frequency resource index when the terminal sends the uplink data. Parameter N_DMRS' parameter n is the number of DMRS having a mapping relation with the same multiple access resource_DMRSIs' N_DMRS' the index of DMRS selected by uplink data in the DMRS is configured by a high layer and is informed to a terminal through a downlink control channel or a shared channel. Parameter N_MAAs an index of I_{PRB_RA}The number of multiple access resources available on the time-frequency resource of (1), parameter n_MAIs N_MAThe index of the multi-access resource selected by the uplink data in the multi-access resource is configured by the high layer and is informed to the terminal through the downlink control channel or the shared channel.

And thirdly, when a one-to-one mapping relation exists between the DMRS and the multiple access resources, namely the multiple access resources can be uniquely determined through the DMRS, the DMRS can also be uniquely determined through the multiple access resources, and N is carried out at the moment_DMRS＝N_MAAnd the way of determining the inter-group index and the intra-group index can be simplified, i.e., only using the DMRS index or only using the multiple access resource index.

When the inter-group index and the intra-group index are determined using only the DMRS index, the formula is as follows:

the meaning of each parameter in the formula is as described above.

When the inter-group index and the intra-group index are determined using only the multiple access resource index, the formula is as follows:

the meaning of each parameter in the formula is as described above. In addition, the respective index parameters can also replace positions in the formula.

In the scheme, the position of the HARQ indication channel is determined by adopting the position of the scheduling-free time-frequency resource, the DMRS characteristic and the used multiple-access resource. When only one subband is used for scheduling-free transmission in a time slot, a simpler way is to determine the time-frequency resource position of the HARQ indication channel only by using the DMRS correlation property and the used multiple access resource.

Specifically, after the terminal transmits uplink data on the corresponding scheduling-free resource in the subframe n, the uplink data will be transmitted at n + k_PHICHAnd detecting the HARQ indication channel on each downlink subframe. Wherein k is_PHICHThe parameters are preset parameters known by both the base station and the terminal, or parameters configured through high-level signaling. The specific time-frequency position of the corresponding HARQ indication channel in the subframe is determined by the used uplink resource, and the uplink resource comprises DMRS characteristics and multiple access resources. At this time, multiple HARQ indicator channels may still be mapped on the same time-frequency resource, i.e. the location of the HARQ indicator channel may still be grouped by index

Is determined in which

For inter-group indexing, characterizing the HARQ indicator channel groups that can be supported on that slotThe index is a function of the number of times,

for the intra-group index, the index of the HARQ indicator channel multiplexed in one group is characterized, that is, the index is used for distinguishing the different HARQ indicator channels multiplexed on the same time-frequency resource.

Index set

Is determined in a similar manner to that described above, but requires the parameter I in the formula described above_{PRB_RA}Is set to 0. As a simple example, when there is a one-to-many mapping relationship between DMRSs and multiple access resources, the index set may be determined as follows:

in the above formula, the HARQ indication channel group where the HARQ indication channel is located is determined by using the available DMRS resources and multiple access resources, and the index in the group is determined by using the multiple access resources. The following describes the determination of the index set by taking a simple example:

the number of available DMRSs is 4, the number of multiple access resources corresponding to each DMRS is 8, and therefore the number of the total available resources is 32; the number of the HARQ indicator channel groups is 4, and the number of HARQ indicator channels multiplexing the same time-frequency resource in each group is 8, then the index group determination method is as follows:

wherein n is_DMRSThe value range is 0-3, n_MAThe' range is 0 to 7.

The following table shows index group values corresponding to different DMRS indexes and MA indexes.

Table 2: different DMRS indices n_DMRSAnd MA index n_MA' corresponding index set value

As can be seen from the above example, indexes of DMRS and multiple access resources are different, and values of the obtained HARQ indicator channel index groups are also different, which indicates that transmissions are performed on the same time-frequency resource, but terminals using different DMRS and multiple access resources may use different HARQ indicator channels. Therefore, the discrimination of the HARQ indication channel can be completed by adopting the mode.

In the above example of determining the location of the HARQ indication channel using only DMRS and multiple access resources, the index group determination method may also be written as:

still assuming that the number of available DMRSs is 4, and the number of multi-resources corresponding to each DMRS is 8, so that the number of total available resources is 32; and setting the number of the HARQ indication channel groups to be 4, and setting the number of the HARQ indication channels multiplexing the same time-frequency resource in each group to be 8. The above formula should be written as:

wherein n is_DMRSThe value range is 0-3, n_MAThe value range is 0-7.

The HARQ indicator channel index groups corresponding to different DMRSs and multiple access indexes are obtained from the following table:

table 3: alternative DMRS index n_DMRSAnd MA index n_MA' corresponding index set value

It can be seen that, after the DMRS index and the multiple access resource index are replaced, values of HARQ indicator channel index groups obtained by different DMRS indexes and multiple access resource indexes are still different, which indicates that the position of the HARQ indicator channel of the terminal using the specific DMRS and multiple access resource can be determined according to the above formula.

It should be noted that, in this embodiment, the HARQ indication channel may be an actual physical channel, for example, PHICH in LTE-a; or a downlink control channel or a domain in a downlink shared channel, the base station determines the position of the corresponding HARQ indication information according to the time-frequency resource, DMRS and multiple access resource used by uplink transmission, and the terminal searches the HARQ information sent to the terminal in the domain through the index group.

Example two

In this embodiment, a specific process of performing uplink data transmission on the terminal side provided by the present application will be described, which mainly relates to a process of performing first data transmission and performing subsequent data transmission according to received HARQ information in a Media Access Control (MAC) layer, and corresponds to step 501 in the process of fig. 5. The description in this embodiment is divided into two parts, namely an HARQ Entity (Entity) and an HARQ Process (Process).

HARQ entity

For scheduling-free transmission, a HARQ entity exists at the UE side for maintaining multiple parallel HARQ processes, so that the terminal can continuously transmit data while waiting for HARQ feedback of a previous transmission.

The maximum number of parallel HARQ processes supported by each HARQ entity is determined according to the Round-trip time (RTT) of data transmission from the terminal and the period of time of the resource allocated for scheduling-free transmission. For example, if the scheduling-free transmission resources are continuously distributed in time and the RTT of data transmitted by the terminal is 8 symbols, the maximum number of parallel HARQ is 8.

Within each transmission time interval TTI, for each given time-frequency resource for a schedule-free transmission, the HARQ entity determines the HARQ process transmitting on that time-frequency resource. For the determined HARQ process, the HARQ entity is also configured to determine a transmission resource used by the HARQ process, send the received HARQ feedback information or newly transmitted data to the corresponding HARQ process, and instruct the corresponding HARQ process to perform retransmission or new transmission.

For scheduling-free transmission, a new data transmission is triggered by the data generation unit (for generation, packetization of data, etc.) and a request to transmit data is sent to the HARQ entity. After receiving the data transmission request, the HARQ entity establishes an HARQ process, allocates time-frequency resources, DMRS and multiple access resources for uplink transmission to the HARQ process, and stores the allocated resources for new data transmission in the HARQ process. The DMRS and the multiple access resource stored in the HARQ process are used for distinguishing whether the HARQ information sent to the HARQ process by the HARQ entity belongs to the HARQ process.

For the retransmitted data transmission, the same HARQ process is corresponding to the first data transmission. And the HARQ entity allocates time-frequency resources, DMRS and multiple access resources for the retransmission of the HARQ process and transmits the time-frequency resources, the DMRS and the multiple access resources to the corresponding HARQ process.

As with the foregoing resource allocation method in scheduling-free transmission, the method for allocating uplink transmission resources for the HARQ process by the HARQ entity may be two types:

for transmission of new data, transmission resources can be selected with equal probability from available scheduling-free transmission resources (including time-frequency resources, DMRS and multiple access resources) of a resource pool allocated by the base station for the terminal, and allocated to the HARQ process. The available scheduling-free transmission resources refer to time-frequency resources, DMRS and multiple access resources which are not used for new transmission data and retransmission data of the HARQ entity, and ensure that no resource collision occurs when the new transmission data and the retransmission data are transmitted to the HARQ entity (i.e. the terminal).

If the retransmission indication of the HARQ entity needing retransmission is that retransmission is not needed or the retransmission times reach the maximum, taking out the data in the data cache in the corresponding HARQ process, releasing the resources allocated to the HARQ process, resetting the HARQ process, selecting the transmission resources again from the available scheduling-free transmission resources with equal probability, allocating the transmission resources to the HARQ process, and waiting for the retransmission of the data.

And for the HARQ entity needing to be retransmitted, if the retransmission indication is that the retransmission is needed and the retransmission times are not the maximum, determining resources used in the retransmission according to the mapping relation between the resources in the new transmission resource pool and the retransmission resource pool, wherein the resources comprise time-frequency resources, DMRS (demodulation reference signal) and multiple-access resources.

For the transmission of new data, through the signaling of a downlink control channel or the indication of a system high-level signaling, the HARQ entity selects DMRS and multiple access resources indicated to the terminal by the signaling, the DMRS and multiple access resources are used as the DMRS and multiple access resources of the HARQ process, and the time frequency resources are selected from the available time frequency resources configured to the terminal by the base station and allocated to the process according to equal probability;

and for the HARQ entity needing retransmission, if the retransmission indication is that retransmission is needed and the retransmission times are not the maximum, selecting the DMRS and the multiple access resource indicated to the terminal by the signaling as the DMRS and the multiple access resource of the HARQ process, and determining the time frequency resource used in the retransmission according to the mapping relation between the newly transmitted time frequency resource and the retransmitted time frequency resource.

Specifically, the specific processing flow in each TTI includes:

for a given time-frequency resource A used for scheduling-free transmission, the HARQ entity determines the HARQ process corresponding to the time-frequency resource, and determines the resource used by the corresponding HARQ process in the transmission in the following way:

if the given scheduling-free time-frequency resource A is applied to retransmission of a certain HARQ process according to the mapping relationship between the newly transmitted resource and the retransmission resource, and the retransmission indication of the HARQ process is that retransmission is required, selecting the resource of the retransmission according to the mapping relationship between the newly transmitted resource and the retransmission resource, transmitting HARQ information including the selected resource to the corresponding HARQ process, and indicating the process to initiate retransmission; the HARQ process receives and stores the selected resources and initiates retransmission; according to the overall description of the resource allocation, it can be seen that the mapping relationship between the new transmission resource and the retransmission resource may include DMRS, multiple access resource and time-frequency resource, and accordingly, when selecting the retransmission resource, the DMRS, the multiple access resource and the time-frequency resource (i.e. a) of the current retransmission are selected according to the time-frequency resource a and the mapping relationship; or, the mapping relationship between the new transmission resource and the retransmission resource may only include the time-frequency resource, and accordingly, when the retransmission resource is selected, the time-frequency resource a is selected, and the DMRS and the multiple access resource stored in the corresponding HARQ process are used as the retransmission resource.

If the given scheduling-free time-frequency resource is applied to new transmission of a certain HARQ process according to the resource selection condition, sending the data from the data generation unit to the process, and instructing the process to initiate new transmission; and the HARQ process takes the stored resources as the transmission resources of the new data transmission.

HARQ process

Each HARQ process is associated with one HARQ buffer. The buffer is used for storing the uplink data currently being transmitted.

Each HARQ process maintains a variable CURRENT _ TX _ NB, which is used for indicating the transmission times of data in the CURRENT buffer; maintaining variable HARQ _ FEEDBACK for indicating ACK/NACK FEEDBACK information of data in the current cache; and maintaining a variable HARQ _ RE for indicating whether the data in the current cache needs to be retransmitted or not, wherein the variable is 1 to indicate that the retransmission is needed, otherwise, the retransmission is not needed. CURRENT _ TX _ NB should be initialized to 0 when the HARQ process is established.

The sequence of redundancy versions is determined in advance and known to both the base station and the terminal. One possible redundancy version sequence is 0,2,3, 1. The HARQ process indicates the index of the redundancy version sequence by the variable CURRENT _ IRV. And updating the variable in a mode of modulus V, wherein V is the length of the redundancy version sequence.

The resources used by the new transmission and retransmission of the data are determined by the HARQ entity and are transmitted to the HARQ process.

The maximum number of transmissions for HARQ is determined by higher layer signaling, indicated by maxHARQ-Tx.

The behavior of the HARQ process is described as follows:

when receiving the HARQ FEEDBACK of a certain transmission data block, the HARQ process sets the variable HARQ _ FEEDBACK as the received value, and sets the variable HARQ _ RE as the received value.

If the HARQ entity triggers a new transmission of data (including the retransmission indication is 0), the HARQ process may perform the following processes:

CURRENT _ TX _ NB is set to 0;

set CURRENT _ IRV to 0;

storing uplink data to be transmitted in a corresponding HARQ buffer;

setting HARQ _ FEEDBACK to NACK;

setting HARQ _ RE to 0;

storing data transmission resources allocated by the HARQ entity, including time-frequency resources, DMRS, and multiple access resources;

instructing the physical layer to transmit data in the HARQ buffer according to the stored data transmission resource and the redundancy version determined according to CURRENT _ IRV;

increment CURRENT _ IRV by 1.

If the HARQ entity triggers a retransmission, the HARQ process may perform the following processing:

increment CURRENT _ TX _ NB by 1;

increment CURRENT _ IRV by 1.

After the above actions are finished, the HARQ process may perform the following processes:

if CURRENT _ TX _ NB is equal to the maximum transmission number of times-1, the HARQ buffer is cleared.

EXAMPLE III

In this embodiment, an HARQ transmission method on the base station side provided by the present invention will be described.

For the scheduling-free transmission scheme, the processing at the base station side can be briefly described as follows:

1. and the base station receives the uplink signal sent by the terminal and performs blind detection.

2. And the base station determines whether the received data is newly transmitted or retransmitted according to the blind detection result and the division and mapping relation of the newly transmitted resource and the retransmission resource.

For newly transmitted data, decoding by directly using soft information output by the multi-user detector during decoding; and for retransmission data, according to the mapping relation between the newly transmitted resource and the retransmission resource, after detection is finished, the previously decoded data in the corresponding cache is taken out, and is combined with the data after the detection and decoded.

3. If the decoded data passes the CRC, reading the terminal ID information from the detected data, determining the position of an HARQ indication channel according to the time-frequency resource position, the multiple access resource and the DMRS of uplink signal transmission, and sending ACK + terminal ID information;

if the decoded data is not checked through CRC, determining the position of the HARQ indication channel according to the corresponding time-frequency resource position, the multiple access resource and the DMRS, sending NACK information, and simultaneously storing the soft information decoded at this time in a corresponding cache for the merging and decoding of the subsequent retransmission. If the retransmission times are larger than the maximum retransmission times, the cache is cleared.

If one-to-one mapping relation exists between the DMRS and the multiple access resources or many-to-one mapping relation exists between the DMRS and the multiple access resources, the condition of the selected multiple access resources can be obtained through the DMRS, and blind detection on the base station side can be completed through detection of the DMRS. Specifically, after receiving data on a certain time-frequency resource block, a base station first performs activation detection on DMRSs to determine which DMRSs are used for data transmission on the time-frequency resource block. One possible detection method is to perform correlation performance detection on all possible DMRSs, and set an energy detection threshold, where DMRSs with correlation performance detection results higher than the detection threshold are all determined to be activated.

The used multiple access resources can be distinguished through the activation of the DMRS, and the multiple access resources required to participate in multi-user detection can be obtained after the DMRS is detected, so that the blind detection process is greatly simplified. Meanwhile, due to the fact that multiple access resources participating in multi-user detection are obtained, the last transmission data corresponding to the retransmission data can be determined through the mapping relation between the new transmission resource pool and each retransmission resource pool, the data can be conveniently read from the cache, and merging and decoding are conducted during decoding.

If one-to-many mapping relationship exists between the DMRS and the multiple access resources, one DMRS may correspond to multiple access resources, and the used multiple access resources cannot be determined through activation of the DMRS, but the blind detection range can still be narrowed, and the detection complexity of the blind detection is reduced.

If the activation detection of the DMRS indicates that a certain DMRS is not activated, the base station may not transmit information on all corresponding HARQ indicator channels, or may transmit NACK information on all corresponding HARQ indicator channels. For the case that one DMRS corresponds to multiple access resources, if a certain DMRS does not pass the activation detection, HARQ indicator channels corresponding to all corresponding access resources should not transmit information, or all HARQ indicator channels should transmit NACK signals.

Because a collision situation may occur during scheduling-free transmission, for example, different terminals select the same DMRS and multiple access resource to transmit on the same time-frequency resource, when the base station performs multi-user blind detection, it may happen that both the data of the two terminals are successfully detected, or only the data of one of the terminals is successfully detected. For the first case, the terminal simply transmits a NACK signal in the corresponding HARQ indication channel. However, for the second type of data, in addition to the ACK signal needs to be transmitted, it is also necessary to inform the terminal ID information that is correctly detected and decoded to avoid the situation that the terminal that is correctly detected and decoded mistakenly thinks that the ACK signal is received, thereby causing data transmission errors.

The terminal ID information in the present application may include the following forms:

C-RNTI. The information is an identifier which is allocated to the terminal by the base station and is used for distinguishing the terminal in the connected state, and the length of the identifier is 16 bits.

S-TMSI. The information is the unique identifier of the terminal and has the length of 48 bits.

3. And generating a terminal identifier according to the C-RNTI or the S-TMSI. The terminal identification is generated according to the C-RNTI or the S-TMSI through some preset rules and can be regarded as the compressed terminal identification, and the overhead in the HARQ indication channel is reduced by improving certain terminal identification conflict probability.

4. Token information. The information is allocated by the base station for distinguishing terminals allocated the same DMRS and/or multiple access resources.

5. And partial uplink data. For example, part or all of the CRC check bits of the uplink data may be used.

The following describes a manner of generating the terminal ID information in accordance with the manner of selecting the resource.

If the terminal is in a connected state, the base station allocates the multiple access resource and the DMRS for the terminal, and the preferred scheme allocates the token bit for the terminal by the base station at the same time. The token bit allocation principle is that different token bits are allocated to the terminals allocated to the same multiple access resource and DMRS. Fig. 9 shows one possible token bit allocation.

In fig. 9, the resources include DMRS, multiple access resources, and/or time-frequency resources. The same resource is allocated to four terminals, and the terminals allocated the same resource obtain different token bits in order to distinguish the four terminals. Considering that there are only four possibilities for the token bit, it is sufficient to characterize it with two bits. Typically, the size of the token bits is related to the maximum number of terminals allocated to the same resource. If the maximum number of terminals allocated with the same resource is M_maxThe number of bits of the token information is

Wherein

Meaning rounding up.

When the base station transmits the ACK/NACK signal, a preferable mode is to transmit ACK + token bits and NACK + zero padding bits/random bits. Wherein the length of the zero padding bits/random bits is the same as the token bits. When the length of the information bit in the HARQ indication channel is

When the token bits are few, a higher-order modulation mode, such as QPSK or 8PSK, may be adopted for modulation, and the modulated symbols are repeatedly encoded and spread, and the position of the HARQ indication channel is determined according to the used time-frequency resource position, DMRS and multiple access resource, and resource mapping and signal transmission are performed.

Another way to send ACK/NACK signals is to transmit 1-bit ACK/NACK information only in the HARQ indicator channel, and to transmit token information in the downlink control channel or the downlink shared channel. The specific mode is that the position of the HARQ indication channel is determined according to the time frequency resource, the DMRS and the multiple access resource, and corresponding ACK/NACK information is transmitted. And if the ACK information is transmitted, determining the position of the corresponding token information according to the time-frequency resource, the DMRS and the multiple-access resource, and transmitting through a downlink control channel or a downlink shared channel.

If the terminal does not finish uplink synchronization, the base station does not allocate C-RNTI for identifying the terminal to the terminal, and one way of informing the terminal of correct detection is to send ACK information and send a terminal unique identifier carried in correct detection data, wherein the identifier is S-TMSI. And if the detection fails, a NACK signal needs to be sent, zero padding or random bit padding is carried out after the NACK signal, and the number of the padded bits is consistent with the number of the S-TMSI bits. And determining the position of the HARQ indication channel according to the used time-frequency resources, the DMRS and the multiple access resources, and transmitting corresponding ACK/NACK information and terminal ID information.

Similar to the former case, the 1-bit ACK/NACK signal and the S-TMSI characterizing the terminal ID information may be transmitted separately, with the S-TMSI being transmitted in a downlink control channel or a downlink shared channel, with the transmission location being transmitted by the time-frequency resources used, the DMRS, and the multiple access resources.

If the terminal is in a connected state, but the base station does not allocate access resources including DMRS and multiple access resources to the terminal, or the base station allocates access resources but does not allocate corresponding token information, at this time, the terminal ID information may be identified by using the C-RNTI allocated by the base station when the terminal accesses the network. And if the detection fails and a NACK signal needs to be sent, zero padding or random bit padding is carried out after the NACK signal, and the number of the padded bits is consistent with that of the C-RNTI. And determining the position of the HARQ indication channel according to the used time-frequency resources, the DMRS and the multiple access resources, and transmitting corresponding ACK/NACK information and terminal ID information.

In a similar manner to the foregoing, the 1-bit ACK/NACK signal and the C-RNTI may be transmitted separately, and the C-RNTI may be transmitted in a downlink control channel or a downlink shared channel, and the transmission position thereof is transmitted by the used time-frequency resource, DMRS and multiple access resource.

Considering that the length of S-TMSI is 48 bits and C-RNTI also has 16 bits in the existing standard, the direct transmission of S-TMSI and C-RNTI can help the terminal to accurately distinguish ACK/NACK information, but can bring larger signaling overhead to a downlink transmission channel. One possible solution is to generate a shorter terminal ID based on S-TMSI or C-RNTI, as the terminal ID information, for transmission in the HARQ indicator channel or downlink control channel/downlink shared channel. Wherein, preferably, the terminal ID information can be randomly generated according to the C-RNTI or the S-TMSI.

Due to the shorter terminal identities, the terminal identities of different terminals may still collide. If the number of the terminal identification bits is b, the number of the possible terminal identifications is 2^b. If two terminals select the terminal identifiers with equal probability, the probability of collision is 1/2^2b. Selecting bit number b and ensuring that the probability is less than the probability p that NACK is judged to be ACK in the system performance requirement_N→AAnd (4) finishing. The selection criterion for the number of bits b is therefore:

that is, the probability of terminal identification conflict is not greater than NACK, and the terminal identification conflict is judged to be NACKThe smallest number of bits b of the probability of ACK. Take the requirement in LTE-A as an example, where the probability that NACK is discriminated as ACK needs to be less than p_N→A＝10^-4. For this case, the probability of terminal identity collision is about 6 × 10 when b is 7, which can be deduced from the above formula^-5Is less than p_N→A. Namely, only 7-bit terminal identification is needed to meet the system requirement, and the overhead brought by the transmission of the terminal ID information is greatly reduced.

One way to generate the terminal identification is by pseudo-random sequence generation. The terminal identification is generated, for example, by means of an m-sequence. The base station specifies a generator polynomial for generating an m-sequence, and different terminals generate continuous pseudo-random sequences using the C-RNTI or the S-TMSI or a partial bit sequence of the identifier as an initial state. And then, determining the interception position of the terminal identifier in the pseudo-random sequence according to the C-RNTI or the S-TMSI or the partial bit sequence of the identifier.

The way in which the terminal identity is generated from the m-sequence is illustrated by the following example. Taking C-RNTI as an example, considering that the length of the C-RNTI is 16 bits, the high-order 8 bits are used for determining the initial state, and the low-order 8 bits are used for determining the interception position. Generating m-sequence by using a generator polynomial with maximum degree of 8, and generating the upper 8 bits of C-RNTI, namely C₁₅,…,c₈As its initial state; the lower 8 bits determine the starting truncation position, i.e.

Wherein, c_iIs ith bit data in C-RNTI, p_fA fixed value not less than zero. The truncated position represents the p-th output in m-sequence_clipAnd continuously selecting b bits as a terminal identifier as a starting point. The above process can be represented by fig. 10.

Other sequences may be used to generate the terminal identification. For example, using a Gold sequence, the two m-sequence generator polynomials used to generate the Gold sequence are fixed, and the initial state of one of the m-sequences is fixed. The other m-sequence initial state is determined by C-RNTI or S-TMSI or partial sequence of the identifier; and determining the interception position of the terminal identifier in the pseudo-random sequence according to the C-RNTI or the S-TMSI or the partial bit sequence of the identifier.

The other mode is to fix two m-sequence generating polynomials for generating Gold sequences, wherein the initial states of the two m-sequences are determined by C-RNTI or S-TMSI or partial sequences of the identifier; and determining the interception position of the terminal identifier in the pseudo-random sequence according to the C-RNTI or the S-TMSI or the partial bit sequence of the identifier.

The method of implementation of this embodiment is illustrated by the following example.

Gold sequences with a period of 31 are used, the generator polynomial degree of the m-sequence of which is 5. Considering that the C-RNTI is 16 bits, the upper 5 bits are used for initial state determination of the first m-sequence, then 5 bits are used for initial state determination of the second m-sequence, and the lower 6 bits are used for determining the truncation position in the output Gold sequence. Specifically, the initial state of the first m-sequence is c₁₅,…,c₁₁The initial state of the second m-sequence is c₁₀,…,c₆(ii) a The interception position is

Wherein, c_iIs ith bit data in C-RNTI, p_fA fixed value not less than zero. The truncated position represents the p-th output in m-sequence_clipAnd continuously selecting b bits as a terminal identifier as a starting point. The above process can be represented by fig. 11.

The S-TMSI can also use the above described method of generating terminal identities in a sequence based manner. Considering that the S-TMSI is longer than the C-RNTI, only part of the S-TMSI may be truncated for the generation of the terminal identity. For example, in the above two examples, the generation of the terminal identity can also be done by replacing the C-RNTI with the S-TMSI of the lower 16 bits.

In addition to the above terminal ID information generation based on C-RNTI or S-TMSI, the terminal ID information can also be characterized by the transmitted uplink data. One possible way is to add b-bit CRC check bits to the uplink transmission data passing the CRC check, and transmit the check bits as terminal ID information in the HARQ indicator channel or the downlink control channel/shared channel. To ensure higher reliability and lower collision probability, an 8-bit CRC check or a 16-bit CRC check may be selected and the 8-bit CRC check or the 16-bit CRC check may be transmitted to the terminal as the terminal ID information together with the ACK information.

If the base station can perform DMRS collision detection by means of DMRS energy detection or the like, the base station may add a collision detection result when transmitting a NACK signal. The concrete mode is as follows:

1. a base station receives a receiving signal on a certain time frequency resource block, performs activation detection and collision detection on a DMRS (demodulation reference signal), determines a multi-access resource range needing blind detection according to the activated DMRS, and determines whether corresponding uplink data is newly transmitted data or retransmitted data according to the DMRS and the multi-access resource;

2. the base station carries out multi-user detection according to the multi-resource detection range and the corresponding channel estimation to obtain the detection result of the uplink data;

3. if the detection result of the uplink data obtained by detecting a certain multi-access resource passes the CRC, which indicates that the detection is successful, the base station acquires the terminal ID information from the uplink data and transmits ACK + terminal ID information in a corresponding HARQ indication channel or a downlink control channel or a downlink shared channel;

if the detection result of the uplink data obtained by detecting a certain multi-access resource does not pass CRC check and DMRS conflict detection corresponding to the uplink data indicates that no conflict occurs, the base station transmits NACK + non-conflict indication in a corresponding HARQ indication channel or a downlink control channel or a downlink shared channel and stores the detection result in a corresponding cache;

if the uplink data detection result obtained by detecting a certain multiple access resource does not pass the CRC check and the DMRS conflict detection corresponding to the uplink data indicates that a conflict occurs, the base station transmits NACK + conflict indication in a corresponding HARQ indication channel, or a downlink control channel, or a downlink shared channel, and clears a corresponding cache.

Both the base station side collision detection and the DMRS activation detection may use correlation energy detection. Specifically, an energy detection threshold and a collision detection threshold are set according to the DMRS correlation and the terminal open loop power control parameter, and the collision detection threshold is larger than the energy detection threshold. Firstly, a base station carries out correlation energy detection on the DMRS, and if the detection result is lower than an energy detection threshold, the DMRS is not activated; if the detection result is higher than the energy detection threshold but lower than the collision detection threshold, the DMRS is activated and no collision occurs; and if the detection result is higher than the collision detection threshold value, the DMRS is activated and a collision occurs.

Fig. 12 is a schematic diagram of the detection method.

If the DMRS does not collide, the detection failure may be due to poor channel conditions or large interference from other terminals, and the retransmission may effectively improve the reliability of data transmission; if DMRS collides, the detection failure may be caused by that different terminal channels cannot be distinguished due to DMRS collision, and at this time, the retransmission has a limited effect on improving the reliability of data transmission, and the terminal should reselect resources to attempt data transmission.

For some DMRSs, it may not be used for transmission of uplink data. At this time, through the active detection of the DMRSs, the base station can find the active DMRSs and transmit NACK or no data to the unused DMRSs in all the corresponding HARQ indicator channels. However, when the condition of the terminal transmission channel is poor, it may happen that the terminal transmits data, but the DMRS activation detection at the base station side does not detect the corresponding DMRS, which causes the base station to consider that the DMRS and the corresponding multiple access resource are not used for data transmission, and no data is transmitted in the corresponding buffer. In this case, the base station transmits a NACK signal or does not transmit data in the corresponding HARQ indicator channel, and for both cases, the terminal initiates a retransmission considering that the previous transmission was not successful. During retransmission, since the base station does not store the data of the previous transmission, the merging and decoding cannot improve the probability of successful detection, and even the more wrong the decoding occurs. In this case, the better way for the terminal to re-initiate the first transmission, rather than re-transmit.

One possible solution is to send a retransmission/new transmission indication at the same time as the NACK signal is sent. If the activation of the DMRS is detected, but the detection result does not pass CRC check, NACK and retransmission indication are sent in a corresponding HARQ indication channel; and if the activation of the DMRS is not detected, transmitting NACK and a new transmission indication in a corresponding HARQ indication channel. Furthermore, the retransmission and new transmission indications may be combined with collision detection indications, i.e. a retransmission indication is used to characterize a non-collision indication and a new transmission indication is used to characterize a collision indication. In addition, the retransmission/new transmission indication can be transmitted separately from the NACK signal, that is, the ACK/NACK signal is transmitted in the HARQ indication channel, and the retransmission/new transmission indication is transmitted in the downlink control channel or the downlink shared channel.

Example four:

in this embodiment, the detection processing for HARQ information in the HARQ transmission method at the terminal side provided by the present invention, that is, the processing of step 506 and step 507 in fig. 5, will be described.

After finishing one uplink scheduling-free transmission, the terminal detects the HARQ indication channel of the transmission on the time-frequency resource of the HARQ indication channel.

If the transmission content in the HARQ indication channel is ACK + terminal ID information, the terminal side processes as follows:

the terminal detects the content in the HARQ indication channel, and if ACK is detected, the terminal ID information in the HARQ indication channel is further detected; and if the terminal ID information in the HARQ indication channel is matched with the terminal ID information, transmitting ACK to a higher layer. In this case, it is explained that the uplink transmission corresponding to the HARQ indicator channel is correctly received by the base station. The terminal can initiate new transmission or finish uplink transmission, and enter a waiting state or a dormant state;

the terminal detects the content in the HARQ indication channel, and if ACK is detected, the terminal ID information in the HARQ indication channel is further detected; if the terminal ID information in the HARQ indication channel is not matched with the terminal ID information, the information for terminating the transmission is transmitted to a high layer, and a request for retransmitting the uplink transmission content corresponding to the HARQ indication channel is initiated. In this case, it is explained that the uplink transmission corresponding to the HARQ indicator channel has resource collision on the base station side, and the data transmitted by the terminal is not decoded correctly, while the data transmitted by the same resource used by another terminal that has collided with the terminal is decoded correctly. At this time, the terminal continues to retransmit the uplink data, which cannot improve the transmission reliability, so the terminal terminates the transmission and reselects the resource in the resource pool for uplink data transmission (which is equivalent to newly transmitting the uplink data which is not successfully transmitted).

The terminal detects the content in the HARQ indication channel, and if NACK is detected or no transmission of data is detected, it delivers NACK to the higher layer. In this case, the uplink data sent by the terminal is not decoded successfully, and the retransmission helps to improve the reliability of data transmission, so that if the maximum transmission frequency is not reached, the terminal initiates retransmission by using a new redundancy version; otherwise, the terminal will terminate the transmission and select a new resource for the uplink data transmission attempt.

The above-described terminal-side processing can be described with fig. 13. In the above processing at the terminal side, the terminal ID information includes C-RNTI allocated by the base station, or S-TMSI unique to the terminal, or a terminal-specific identifier generated based on the C-RNTI or the S-TMSI, or a token bit allocated by the base station.

If only ACK/NACK information is transmitted in the HARQ indicator channel and the terminal ID information is transmitted in the specific time-frequency resource of the downlink control channel or the downlink shared channel, the terminal side will behave as follows:

the terminal detects the content in the HARQ indication channel, if ACK is detected, the terminal ID information is detected according to the time frequency resource, the multiple access resource and the appointed position of DMRS in the downlink control channel or the downlink shared channel used in the uplink transmission; and if the detected terminal ID information is matched with the terminal ID information, transmitting ACK to a higher layer. In this case, it is explained that the uplink transmission corresponding to the HARQ indicator channel is correctly received by the base station. The terminal can initiate new transmission or finish uplink transmission, and enter a waiting state or a dormant state;

the terminal detects the content in the HARQ indication channel, if ACK is detected, the terminal ID information is detected according to the time frequency resource, the multiple access resource and the appointed position of DMRS in the downlink control channel or the downlink shared channel used in the uplink transmission; and if the detected terminal ID information is not matched with the terminal ID information, sending NACK information and a new transmission request to a high layer, informing the high layer of terminating the information of the transmission, and requesting to retransmit the uplink transmission content corresponding to the HARQ indication channel. In this case, it is explained that the uplink transmission corresponding to the HARQ indicator channel has resource collision on the base station side, and the data transmitted by the terminal is not decoded correctly, while the data transmitted by the same resource used by another terminal that has collided with the terminal is decoded correctly. At this time, the terminal continues to retransmit the uplink data, which cannot improve the transmission reliability, so the terminal terminates the transmission and reselects the resource in the resource pool for uplink data transmission (which is equivalent to newly transmitting the uplink data which is not successfully transmitted).

The terminal detects the content in the HARQ indication channel, and if NACK is detected, the terminal transmits NACK to a higher layer. In this case, the uplink data sent by the terminal is not decoded successfully, and the retransmission helps to improve the reliability of data transmission, so that if the maximum transmission frequency is not reached, the terminal initiates retransmission by using a new redundancy version; otherwise, the terminal will terminate the transmission and select a new resource for the uplink data transmission attempt.

The above terminal side behavior can still be described with fig. 13. In the terminal side behavior, the terminal ID information includes C-RNTI allocated by the base station, or S-TMSI unique to the terminal, or terminal-specific identification generated according to the C-RNTI or the S-TMSI, or token bits allocated by the base station.

If the content transmitted in the HARQ indication channel is ACK + terminal ID information and NACK + retransmission indication information, the behavior of the terminal side is described as follows:

the terminal detects the content in the HARQ indication channel, and if ACK is detected, the terminal ID information in the HARQ indication channel is further detected; if the terminal ID information in the HARQ indication channel is not matched with the terminal ID information, the high layer is informed of the information for stopping the transmission and requests to retransmit the uplink transmission content corresponding to the HARQ indication channel by sending NACK information and a new transmission request. In this case, it is explained that the uplink transmission corresponding to the HARQ indicator channel has resource collision on the base station side, and the data transmitted by the terminal is not decoded correctly, while the data transmitted by the same resource used by another terminal that has collided with the terminal is decoded correctly. At this time, the terminal continues to retransmit the uplink data, which cannot improve the transmission reliability, so the terminal terminates the transmission and reselects the resource in the resource pool for uplink data transmission (which is equivalent to newly transmitting the uplink data which is not successfully transmitted).

The terminal detects the content in the HARQ indication channel, and if NACK is detected, the terminal further detects the retransmission indication. And if the information needing to be retransmitted is detected, transmitting NACK to a higher layer. In this case, it is described that the base station finds that DMRSs do not collide by collision detection of the DMRSs, but uplink data of the user is not successfully decoded due to channel conditions and the like. At this time, data of other redundancy versions is transmitted, and the base station decodes the data in a combined manner to improve the success rate of detection, so that if the maximum transmission times is not reached at this time, the terminal transmits the data by using the other redundancy versions.

The terminal detects the content in the HARQ indication channel, and if NACK is detected, the terminal further detects the retransmission indication. If the information needing to be retransmitted is not detected, the information for terminating the transmission is transmitted to a high layer, and a request for retransmitting the uplink transmission content corresponding to the HARQ indication channel is initiated. In this case, it is described that the base station finds, through DMRS detection, that a DMRS inserted for uplink transmission by the terminal conflicts with DMRSs used by other terminals, and all the conflicting terminals are decoded successfully; at this time, the retransmission has a limited capability for improving the detection reliability of the base station, so the terminal will terminate the transmission and reselect the resource in the resource pool for transmitting the uplink data which has failed to be transmitted.

The above-described terminal-side behavior can be described with reference to fig. 14. In the terminal side behavior, the terminal ID information includes C-RNTI allocated by the base station, or S-TMSI unique to the terminal, or terminal-specific identification generated according to the C-RNTI or the S-TMSI, or token bits allocated by the base station. The retransmission indication information can directly use 1-bit information to indicate whether to retransmit or not, and can also be characterized by 1-bit collision information. For example, 1 indicates that a collision occurs, and the terminal initiates a new transmission without retransmitting; and 0 indicates that no collision occurs, and the terminal retransmits the uplink data by using the new redundancy version.

If only ACK/NACK information is sent in the HARQ indication channel, and the terminal ID information and retransmission indication information are transmitted in a downlink control channel or a downlink shared channel, under the condition, the terminal side acts similarly to the description, and the difference is that if the terminal detects the ACK signal, the terminal further reads the corresponding terminal ID information in the downlink control channel or the downlink shared channel according to the used multiple access resource and DMRS; and if the terminal detects the NACK signal, reading corresponding retransmission indication information in a downlink control channel or a downlink shared channel according to the DMRS and/or the multiple access resource. The above terminal side behavior can still be described with fig. 14.

It should be noted that, the HARQ indication channel in this embodiment may be an actual physical channel; or a domain in a downlink control channel, configured to transmit ACK/NACK information and terminal ID information and/or retransmission indication information; or a field in the downlink shared channel, for transmitting the ACK/NACK information, as well as the terminal ID information and/or the retransmission indication information.

The foregoing is a specific implementation of the HARQ transmission method in the present application. In the above description, scheduling-free transmission based on the non-orthogonal multiple access technology is taken as an example, and in fact, the HARQ transmission method may be applied to other transmission schemes.

Corresponding to the HARQ transmission method at the base station side, the present application also provides an HARQ transmission device, which may be located in a base station. Fig. 15 is a schematic diagram of the basic structure of the corresponding apparatus. As shown in fig. 15, the apparatus includes: a signal detection unit and a transmission unit.

The signal detection unit is used for receiving the signal sent by the terminal and carrying out signal detection, decoding and CRC check. A sending unit, configured to determine, according to terminal information carried in the signal, identification information of the terminal when the signal detection unit determines that the CRC check is passed, and send acknowledgement ACK information and the identification information of the terminal; and is further configured to transmit non-acknowledgement, NACK, information or not transmit HARQ information when the signal detection unit determines that the CRC check is not passed.

Corresponding to the HARQ transmission method at the terminal side, the present application also provides an HARQ transmission device, which may be located in a terminal. Fig. 16 is a schematic diagram of the basic structure of the corresponding apparatus. As shown in fig. 16, the apparatus includes: a transmitting unit and a receiving unit.

The transmitting unit is used for transmitting an uplink signal to the base station. A receiving unit, configured to receive HARQ information of an uplink signal on a time-frequency resource of an HARQ indicator channel; when the received HARQ information is ACK information, extracting identification information of a terminal corresponding to the HARQ information from the information sent by the base station; if the identification information is consistent with the identification information of the terminal, determining that the uplink signal is correctly received; if the identification information is not consistent with the identification information of the terminal, the transmission is terminated, and the uplink signal is transmitted again for the first time; and when the received HARQ information is NACK information, retransmitting the uplink signal or retransmitting the uplink signal for the first time.

As described above, the present application provides an HARQ transmission scheme. By transmitting the terminal ID information while transmitting the ACK signal, the problem that the terminal detects an ACK/NACK signal incorrectly due to collision can be avoided; in addition, the terminal directly initiates new transmission after receiving the ACK signal and finding that the ID information of the terminal is not matched, so that the problem that the reliability of data transmission cannot be improved by retransmission under the condition is solved. Preferably, the position of the HARQ indication channel is determined according to the time-frequency resource position for carrying the uplink signal, the multiple access resource used by the uplink signal, and the DMRS characteristic of the uplink signal, so that more users can be multiplexed onto the same physical resource block.

In a word, the HARQ transmission scheme in the present application can improve the reliability and stability of the scheduling-free transmission system.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A method for HARQ transmission, comprising:

if the CRC fails, sending non-confirmed NACK information, or not sending HARQ information;

before the ACK information or the NACK information is sent, the method comprises the following steps: determining a time-frequency resource of an HARQ indication channel corresponding to the signal according to a time-frequency resource position for bearing the signal, a multiple access resource used by the signal and the DMRS characteristic of the signal;

2. The method of claim 1, wherein the identification information of the terminal is carried in a HARQ indication channel, a downlink control channel, or a downlink shared channel.

3. The method of claim 2, wherein if the identification information of the terminal is carried in the HARQ indicator channel, then when the NACK information is sent, redundant information having a length same as that of the identification information of the terminal is supplemented after the NACK information.

4. The method of claim 1, wherein the identification information of the terminal is a cell radio network temporary identity (C-RNTI), a temporary mobile subscriber identity (S-TMSI), a terminal identity generated according to the C-RNTI or the S-TMSI, token information allocated by a base station, or a part of uplink data sent by the terminal.

5. The method of claim 4, wherein the number of bits of the token information is

Wherein

6. The method of claim 5, wherein randomly generating the identification information of the terminal comprises: and generating the identification information of the terminal through a pseudo-random sequence.

7. The method of claim 6, wherein the generating the identification information of the terminal through the pseudo-random sequence comprises:

alternatively, the first and second electrodes may be,

8. The method of claim 1, wherein prior to performing the signal detection, the method comprises: performing DMRS collision detection;

9. The method of claim 1, wherein before receiving the uplink signal transmitted by the terminal, the method comprises:

10. The method of claim 9, wherein the base station determines the DMRS and multiple access resources configured for the terminal based on the monitored network loading.

11. The method of claim 10, wherein the determining the DMRS and multiple access resources configured for the terminal comprises:

12. The method of claim 1, wherein the time-frequency resource of the HARQ indicator channel is defined by an index group

a channel group index is indicated for the HARQ,

for intra-group sequence indexing, said index group

13. The method of claim 12, wherein the index set is determined when there is no mapping relationship between the DMRS and the multiple access resource or when there is a one-to-many mapping relationship between the DMRS and the multiple access resource

The method comprises the following steps:

alternatively, the first and second electrodes may be,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

The method comprises the following steps:

alternatively, the first and second electrodes may be,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

The method comprises the following steps:

alternatively, the first and second electrodes may be,

the number of channel groups is indicated for HARQ.

14. The method of any one of claims 1 to 13, wherein said performing signal detection comprises:

15. The method of claim 14, wherein the DMRS activation detection comprises: and performing correlation energy detection on all possible DMRSs, and judging that the DMRS of which the detection result is higher than a set energy detection threshold is activated.

16. The method of claim 14, wherein if the signal is determined to be retransmitted data according to the signal detection result, the method comprises, after detecting the signal and before performing decoding processing: and determining the previous transmission data corresponding to the retransmission data by utilizing the mapping relation between the new transmission resource pool and each retransmission resource pool according to the multiple access resource corresponding to the activated DMRS, and merging and decoding during the decoding processing.

17. The method of claim 14, wherein for the DMRS that is determined to be inactive, the base station does not transmit information on all HARQ indicator channels corresponding to the inactive DMRS, or wherein the base station transmits NACK information on all HARQ indicator channels corresponding to the inactive DMRS;

18. A method for HARQ transmission, comprising:

a first terminal sends an uplink signal to a base station;

when the received HARQ information is NACK information, retransmitting the uplink signal or retransmitting the uplink signal for the first time;

wherein the time-frequency resource of the HARQ indication channel is determined according to the time-frequency resource position for bearing the signal, the multiple access resource used by the signal and the DMRS characteristic of the signal.

19. The method of claim 18, wherein determining that the uplink signal is correctly received comprises: sending ACK information to an upper layer, and finishing the transmission;

and/or the presence of a gas in the gas,

20. The method of claim 19, wherein the first terminal determines the HARQ information to be NACK information when the first terminal does not receive the HARQ information on time-frequency resources of a HARQ indicator channel.

21. The method according to claim 19 or 20, wherein when the received HARQ information is NACK information, the retransmitting or retransmitting the uplink signal for the first time comprises: detecting a conflict indication or a retransmission/new transmission indication, and if the conflict indication is not conflict or the retransmission/new transmission indication is a retransmission indication, sending NACK information and a retransmission request to an upper layer until the maximum transmission times are reached; if the conflict indication is a conflict or the retransmission/new transmission indication is a new transmission indication, sending NACK information and a new transmission request to an upper layer for indicating the upper layer to perform the first transmission on the uplink signal again;

22. The method of claim 21, wherein a HARQ _ RE in a HARQ process corresponding to the uplink signal is utilized to carry the retransmission request or the new transmission request.

23. The method of claim 19, wherein the transmitting, by the first terminal, the uplink signal to the base station comprises:

in each transmission time interval TTI, for each time-frequency resource used for scheduling-free transmission, the HARQ entity determines the HARQ process corresponding to the time-frequency resource, and sends the received HARQ information or new transmission data corresponding to the HARQ process to the corresponding HARQ process and indicates the corresponding HARQ process to perform retransmission or new transmission; the DMRS and the multiple access resources stored in the HARQ process are used for distinguishing whether HARQ information sent to the HARQ process by an HARQ entity belongs to the HARQ process, and the HARQ entity is used for maintaining a plurality of parallel HARQ processes.

24. The method of claim 23, wherein the allocating time-frequency resources, DMRS, and multiple-access resources for the HARQ process comprises: determining DMRS and multiple access resources allocated to the first terminal according to a command in a downlink control channel or configuration of a system high-level signaling, using the DMRS and multiple access resources as DMRS and multiple access resources for transmitting the uplink signal, and randomly selecting time frequency resources from available time frequency resources of a time frequency resource pool set by a base station for the first terminal; or randomly selecting multiple access resources and DMRS with equal probability from available resources of a resource pool configured by a base station for the first terminal, and randomly selecting time-frequency resources from the available resources of the configured resource pool;

and/or the presence of a gas in the gas,

25. The method of claim 24, wherein the selecting the retransmission resource for the HARQ process according to the mapping relationship comprises: selecting a retransmission time-frequency resource for the HARQ process according to the mapping relation; when the HARQ process initiates data retransmission, the stored DMRS and multiple access resources and the received retransmitted time-frequency resources are utilized to carry out the HARQ process;

26. The method of claim 24, wherein the available resources are time-frequency resources, DMRS, and multiple-access resources that are not used for new transmissions and retransmissions of data by the HARQ entity;

27. The method of claim 24, comprising: and when the retransmission indication received by the HARQ entity is that retransmission is not needed or the retransmission times reach the maximum, the HARQ entity takes out the data in the data cache from the corresponding HARQ process, releases the resources allocated to the HARQ process and resets the HARQ process.

28. The method according to claim 18, 19, 20, 22, 23, 24, 25, 26 or 27, wherein the time-frequency resource of the HARQ indicator channel is defined by an index group

a channel group index is indicated for the HARQ,

for intra-group sequence indexing, said index group

29. The method of claim 28, wherein the index set is determined when there is no mapping between the DMRS and the multiple access resource or when there is a one-to-many mapping between the DMRS and the multiple access resource

The method comprises the following steps:

alternatively, the first and second electrodes may be,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

The method comprises the following steps:

alternatively, the first and second electrodes may be,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

The method comprises the following steps:

alternatively, the first and second electrodes may be,

the number of channel groups is indicated for HARQ.

30. A hybrid automatic repeat request, HARQ, transmission apparatus, comprising: a signal detection unit and a transmission unit;

the sending unit is configured to determine, according to terminal information carried in the signal, identification information of the terminal when the signal detection unit determines that the CRC check is passed, and send acknowledgement ACK information and the identification information of the terminal; the signal detection unit is further configured to send non-acknowledgement NACK information or not send HARQ information when the signal detection unit determines that the CRC check fails;

before the sending unit sends the ACK information or the NACK information, the sending unit is further configured to determine, according to a time-frequency resource location carrying the signal, a multiple access resource used by the signal, and a DMRS characteristic of the signal, a time-frequency resource of an HARQ indicator channel corresponding to the signal; and sending the ACK information or NACK information on the determined time-frequency resource of the HARQ indication channel.

31. The apparatus of claim 30, wherein the identification information of the terminal is carried in a HARQ indication channel, a downlink control channel, or a downlink shared channel.

32. The apparatus of claim 31, wherein if the identifier information of the terminal is carried in the HARQ indicator channel, the sending unit supplements, when sending the NACK information, redundant information having a length that is the same as that of the identifier information of the terminal after the NACK information.

33. The apparatus of claim 30, wherein the identification information of the terminal is a cell radio network temporary identity C-RNTI, a temporary mobile subscriber identity S-TMSI, a terminal identity generated according to the C-RNTI or the S-TMSI, token information allocated by a base station, or a part of uplink data sent by the terminal.

34. The apparatus of claim 33, wherein the number of bits of the token information is

Wherein

and/or in the sending unit, randomly generating the identification information of the terminal according to the C-RNTI or the S-TMSI, wherein the bit number of the identification information of the terminal is as follows:

35. The apparatus of claim 34, wherein the randomly generating, in the transmitting unit, the identification information of the terminal comprises: and generating the identification information of the terminal through a pseudo-random sequence.

36. The apparatus of claim 35, wherein the generating, in the sending unit, the identification information of the terminal through the pseudo-random sequence comprises:

alternatively, the first and second electrodes may be,

37. The apparatus according to claim 30, wherein in the signal detection unit, collision detection for DMRS is performed before the signal detection is performed;

when the collision detection result of the DMRS is a collision, if the signal fails to pass the CRC check, the sending unit is further configured to clear the buffer of the corresponding signal, and send a collision indication or a new transmission indication; when the collision detection result of the DMRS is non-collision, if the signal fails to pass the CRC check, the signal detection unit is further configured to store the detection result in a buffer of the corresponding signal, and the transmission unit is further configured to transmit a non-collision indication or a retransmission indication.

38. The apparatus of claim 30, wherein before the signal detection unit receives the uplink signal transmitted by the terminal,

the signal detection unit is further configured to configure, through signaling of a downlink control channel or system high-level signaling, a DMRS and a multiple access resource for the terminal, for uplink signal transmission of the terminal; or, the signal detection unit is further configured to configure a resource pool for the terminal, so as to be used for uplink signal transmission of the terminal; wherein the resource pool comprises DMRS, multiple access resources and/or time frequency resources.

39. The apparatus of claim 38, wherein the signal detection unit is further configured to determine DMRS and multiple access resources configured for the terminal according to the monitored network load condition.

40. The apparatus of claim 39, wherein the determining, in the signal detection unit, the DMRS and multiple access resources configured for the terminal comprises:

when the network load exceeds a set threshold value, increasing the number of terminals configured with the same multiple access resource and/or DMRS;

41. The apparatus of claim 30, wherein the time-frequency resource of the HARQ indicator channel is defined by an index group

a channel group index is indicated for the HARQ,

for intra-group sequence indexing, said index group

42. The apparatus of claim 41, wherein the index set is determined when there is no mapping relationship between the DMRS and the multiple access resource or when there is a one-to-many mapping relationship between the DMRS and the multiple access resource

The method comprises the following steps:

alternatively, the first and second electrodes may be,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

The method comprises the following steps:

alternatively, the first and second electrodes may be,

wherein, I_{PRB_RA}For carrying the cable of the time frequency resource of the said signalIntroduction, N_MAIs at I_{PRB_RA}Total number of available multiple access resources, n, on corresponding time-frequency resources_MAMultiple access resources used for said signal are in N_MAIndex in multiple access resources, N_DMRS' number of available DMRSs corresponding to multiple access resources used for the signal, n_DMRS' DMRS used for the signal is at N_DMRS' an index in the number of DMRSs,

indicating the number of channel groups for HARQ;

and/or the presence of a gas in the gas,

The method comprises the following steps:

alternatively, the first and second electrodes may be,

wherein, I_{PRB_RA}For the index of the time-frequency resource carrying the signal, N_MAIs at I_{PRB_RA}Total number of available multiple access resources, n, on corresponding time-frequency resources_MAMultiple access resources used for said signal are in N_MAIndex in multiple access resources, N_DMRSIs at I_{PRB_RA}Available on corresponding time-frequency resourcesNumber of DMRS, n_DMRSDMRS used for the signal at N_DMRSThe DMRS index in each of the DMRSs,

the number of channel groups is indicated for HARQ.

43. The apparatus according to any one of claims 30 to 42, wherein in the signal detection unit, the performing signal detection comprises:

and carrying out DMRS activation detection according to the signal, and carrying out the detection of the signal by using the multiple access resource corresponding to the DMRS which is judged to be activated.

44. The apparatus of claim 43, wherein the DMRS activation detection comprises: and performing correlation energy detection on all possible DMRSs, and judging that the DMRS of which the detection result is higher than a set energy detection threshold is activated.

45. The apparatus of claim 43, wherein if the signal is determined to be retransmitted data according to the result of the signal detection, the signal detection unit is further configured to determine, according to the multiple access resource corresponding to the activated DMRS, previous transmission data corresponding to retransmitted data by using a mapping relationship between a new transmission resource pool and each retransmission resource pool, and perform combining and decoding during the decoding process, after the detection of the signal and before the decoding process.

46. The apparatus of claim 43, wherein for the DMRS that is determined to be inactive, the transmitting unit does not transmit information on all HARQ indication channels corresponding to the inactive DMRS or the transmitting unit transmits NACK information on all HARQ indication channels corresponding to the inactive DMRS;

or, if the DMRS determined to be activated fails the CRC check, the transmitting unit transmits NACK information on all HARQ indicator channels corresponding to the activated DMRS, and transmits a retransmission indicator; for the DMRS determined to be inactive, the transmission unit transmits NACK information on all HARQ indication channels corresponding to the inactive DMRS and transmits a new transmission indication.

47. A hybrid automatic repeat request, HARQ, transmission apparatus, comprising: a transmitting unit and a receiving unit;

the receiving unit is configured to receive HARQ information of the uplink signal on a time-frequency resource of an HARQ indicator channel; when the received HARQ information is ACK information, extracting identification information of a terminal corresponding to the HARQ information from information sent by a base station; if the identification information is consistent with the identification information of the terminal, determining that the uplink signal is correctly received; if the identification information is not consistent with the identification information of the terminal, the transmission is stopped, and the uplink signal is transmitted again for the first time; when the received HARQ information is NACK information, retransmitting the uplink signal or retransmitting the uplink signal for the first time;

48. The apparatus according to claim 47, wherein, in the receiving unit,

the determining that the uplink signal is correctly received comprises: sending ACK information to an upper layer, and finishing the transmission;

and/or the presence of a gas in the gas,

49. The apparatus of claim 47, wherein the HARQ information is determined to be NACK information when the HARQ information is not received by the receiving unit on time-frequency resources of a HARQ indication channel.

50. The apparatus of claim 48 or 49, wherein when the received HARQ information is NACK information, the receiving unit performs retransmission or retransmission for the first time on the uplink signal, including: detecting a conflict indication or a retransmission/new transmission indication, and if the conflict indication is not conflict or the retransmission/new transmission indication is a retransmission indication, sending NACK information and a retransmission request to an upper layer until the maximum transmission times are reached; if the conflict indication is a conflict or the retransmission/new transmission indication is a new transmission indication, sending NACK information and a new transmission request to an upper layer for indicating the upper layer to perform the first transmission on the uplink signal again;

or, when the HARQ information is NACK information, the retransmitting or retransmitting the uplink signal for the first time by the receiving unit includes: NACK information is transmitted to the upper layer.

51. The apparatus of claim 50, wherein the receiving unit carries the retransmission request or the new transmission request by using a HARQ _ RE in a HARQ process corresponding to the uplink signal.

52. The apparatus of claim 48, wherein the transmitting unit transmits the uplink signal to the base station comprises:

when new transmission data exists, the HARQ entity in the sending unit establishes a corresponding HARQ process for the new transmission data, allocates time-frequency resources, DMRS and multiple-access resources for the HARQ process, and sends the allocated resources and the new transmission data to the HARQ process, wherein the allocated time-frequency resources, DMRS and multiple-access resources are saved in the HARQ process;

53. The apparatus of claim 52, wherein the allocating time-frequency resources, DMRS and multiple access resources for the HARQ process comprises: according to the command in the downlink control channel or the configuration of the system high-level signaling, determining DMRS and multiple access resources allocated to the terminal, using the DMRS and multiple access resources as DMRS and multiple access resources for transmitting the uplink signal, and randomly selecting time frequency resources from available time frequency resources of a time frequency resource pool set by a base station for the terminal; or randomly selecting multiple access resources and DMRS with equal probability from available resources of a resource pool configured for the terminal by the base station, and randomly selecting time-frequency resources from the available resources of the configured resource pool;

and/or the presence of a gas in the gas,

54. The apparatus of claim 53, wherein the selecting the retransmission resource for the HARQ process according to the mapping relationship comprises: selecting a retransmission time-frequency resource for the HARQ process according to the mapping relation; when the HARQ process initiates data retransmission, the stored DMRS and multiple access resources and the received retransmitted time-frequency resources are utilized to carry out the HARQ process;

55. The apparatus of claim 53, wherein the available resources are time-frequency resources, DMRS and multiple-access resources that are not used for new transmissions and retransmissions of data by the HARQ entity;

56. The apparatus of claim 53, wherein in the sending unit, when the retransmission indication received by the HARQ entity indicates that no retransmission is required or the number of retransmissions reaches the maximum, the HARQ entity fetches the data in the data buffer from the corresponding HARQ process, releases the resource allocated to the HARQ process, and resets the HARQ process.

57. The apparatus of claim 47, 48, 49, 51, 52, 53, 54, 55 or 56, wherein the time-frequency resource of the HARQ indication channel is defined by an index group

a channel group index is indicated for the HARQ,

for intra-group sequence indexing, said index group

58. The apparatus of claim 57, wherein the index set is determined when there is no mapping between the DMRS and the multiple access resource or when there is a one-to-many mapping between the DMRS and the multiple access resource