CN110912658B

CN110912658B - Method, apparatus, and computer storage medium for reference signal configuration in a communication system

Info

Publication number: CN110912658B
Application number: CN201811073215.0A
Authority: CN
Inventors: 李栋; 刘勇; 马川
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2018-09-14
Filing date: 2018-09-14
Publication date: 2022-06-03
Anticipated expiration: 2038-09-14
Also published as: CN110912658A

Abstract

Embodiments of the present disclosure provide methods, apparatuses, and computer-readable media for communication. One method described herein includes determining a resource selection pattern to employ; in response to determining to employ a mobile station autonomous resource selection mode, selecting resources for transmission from a resource pool or carrier bandwidth partitioning (BWP) based on channel sensing; evaluating an interference condition of the selected resource; and determining configuration information of a reference signal for the transmission based on a result of the evaluation, wherein the configuration information includes a reference signal sequence for the reference signal, and a length of the reference symbol sequence is determined by a bandwidth of the resource pool or carrier BWP; and transmitting a partial sequence of the reference signal sequence corresponding to the selected resource on the selected resource based on the configuration information. By using the embodiment of the disclosure, the interference can be reduced, and the transmission performance can be improved.

Description

Method, apparatus, and computer storage medium for reference signal configuration in a communication system

Technical Field

Embodiments of the present disclosure relate generally to the field of communication systems, and, in particular, to a method, apparatus, and computer storage medium for reference signal configuration in a communication system.

Background

The statements in this section are intended to facilitate a better understanding of the present disclosure. Accordingly, the contents of this section should be read on this basis and should not be construed as an admission as to which pertains to the prior art or which does not.

With the development of wireless communication technology, various communication applications have emerged to meet different user demands. For example, vehicle communication (V2X) Side Links (SLs) were introduced in Long Term Evolution (LTE) release 14 developed by the third generation partnership project (3GPP) to support direct communication of basic road safety services (e.g., vehicle status information such as location, speed, heading, etc.) between the vehicle and the vehicle/pedestrian/infrastructure.

Meanwhile, due to the increase of communication traffic, spectrum resources are increasingly scarce. To alleviate resource pressure, communication systems often allow multiple transmissions to be scheduled on the same resource or allow multiple services to use the same resource pool in a contention manner. These approaches on the one hand improve the resource utilization and on the other hand also lead to an increase in the interference level.

How to reduce interference and improve communication performance is a problem to be solved in a communication system.

Disclosure of Invention

The present disclosure presents methods, apparatuses, and computer storage media for reference signal configuration in a communication network.

In a first aspect of the present disclosure, a method for communication is provided. The method includes determining a resource selection pattern to employ; in response to determining to employ a mobile station autonomous resource selection mode, selecting resources for transmission from a resource pool or carrier bandwidth partitioning (BWP) based on channel sensing; evaluating an interference condition of the selected resource; and determining configuration information for the transmitted reference signal based on a result of the evaluation, the configuration information comprising a reference signal sequence for the reference signal, a length of the reference symbol sequence being determined by the resource pool or a bandwidth of the carrier BWP; and transmitting a partial sequence of the reference signal sequence corresponding to the resource on the selected resource based on the configuration information.

In some embodiments, the configuration information may further include at least one of a cyclic shift (corresponding to a frequency domain phase rotation) and an orthogonal cover code for the reference signal.

In some embodiments, determining the configuration information for the transmitted reference signal may comprise: determining a set of reference signal sequences for the reference signal from a set of predetermined reference signal sequences for the resource pool or the carrier BWP. In some embodiments, each set of reference symbol sequences in the set of predetermined reference signal sequences may comprise the same one reference signal sequence for transmission over a plurality of symbols in one transmission time interval. In some embodiments, each set of reference symbol sequences in the set of predetermined reference signal sequences may comprise a plurality of different reference signal sequences for transmission over a plurality of symbols in one transmission time interval, respectively.

In some embodiments, determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences may comprise: randomly selecting one set of reference signal sequences from the set of predetermined reference signal sequences as a set of reference signal sequences for the reference signal in response to the selected resources being evaluated as non-interfered resources; or using the reference signal sequence set with the highest priority in the predetermined reference signal sequence set as the reference signal sequence set for the reference signal.

In some embodiments, determining the configuration information of a reference signal may further comprise: in response to the selected resource being evaluated as an undisturbed resource, performing at least one of: randomly selecting a cyclic shift for the reference signal from a predetermined set of cyclic shifts; and randomly selecting an orthogonal cover code for the reference signal from a predetermined set of orthogonal cover codes.

In some embodiments, determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences may comprise: in response to the selected resource being evaluated as an interfered resource, selecting a set of reference signal sequences from the predetermined set of reference signal sequences that is the same as a set of reference signal sequences used by an interfering device as a set of reference signal sequences for the reference signal; and selecting a cyclic shift different from the cyclic shift used by the interfering device from a predetermined set of cyclic shifts for the reference signal, or selecting an orthogonal cover code different from the orthogonal cover code used by the interfering device from a predetermined set of orthogonal cover codes for the reference signal.

In some embodiments, determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences may comprise: ranking a set of reference signal sequences used by a plurality of devices based on priorities of transmissions of the plurality of devices in response to the selected resources being evaluated as resources with interference from the plurality of devices; selecting a highest ranked set of reference signal sequences with unused cyclic shifts and/or orthogonal cover codes as a set of reference signal sequences for the reference signal; and randomly selecting a cyclic shift and/or orthogonal cover code from unused cyclic shifts and/or orthogonal cover codes of the selected set of reference signal sequences for the reference signal.

In some embodiments, determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences may comprise: ranking a set of reference signal sequences used by a plurality of devices based on priorities of transmissions of the plurality of devices in response to the selected resources being evaluated as resources with interference from the plurality of devices; and in response to none of the reference signal sequence sets participating in the ranking having unused cyclic shifts and/or orthogonal cover codes, randomly selecting one of the predetermined plurality of reference signal sequence sets that is not used by the plurality of devices or selecting a reference signal sequence set having a highest priority as the reference signal sequence set for the reference signal from the predetermined plurality of reference signal sequence sets that is not used by the plurality of devices; and randomly selecting a cyclic shift and/or an orthogonal cover code for the reference signal.

In some embodiments, the priority of the transmission of each of the plurality of devices may be determined by at least one of: a priority of the transmitted data packet; receiving signal power; and a size of a resource interfered by the device.

In some embodiments, the method may further comprise: receiving a scheduling message for the transmission from a network device in response to determining to employ a resource selection mode of network scheduling; and based on the received scheduling message, selecting resources for the transmission and determining the configuration information for reference signals.

In a second aspect of the present disclosure, another method for communication is provided. The method comprises the following steps: determining a resource selection mode for the terminal device; and in response to the determined resource selection mode being a network scheduling mode, sending a scheduling message to the terminal device; wherein the scheduling message indicates transmission resources for the terminal device and reference signal configuration information, and the reference signal configuration information comprises an indication of a cyclic shift and/or an orthogonal cover code for a reference signal sequence for the terminal device, and a length of the reference signal sequence is determined by a bandwidth of a resource pool or carrier BWP with which the terminal device is associated.

In some embodiments, the reference signal configuration information may further comprise an indication of a reference signal sequence for the terminal device.

In a third aspect of the present disclosure, an apparatus is provided. The apparatus includes at least one processor, and at least one memory having computer program code stored thereon. The memory and the computer program code are configured to, with the processor, cause the apparatus to perform at least the method described in the first aspect of the disclosure.

In a fourth aspect of the present disclosure, another apparatus is provided. The apparatus includes at least one processor, and at least one memory having computer program code stored thereon. The memory and the computer program code are configured to, with the processor, cause the apparatus to perform at least the method described in the second aspect of the disclosure.

In a fifth aspect of the present disclosure, there is provided a computer program product comprising instructions which, when executed on one or more processors, cause performance of any of the methods according to the first or second aspects of the present disclosure.

In a sixth aspect of the present disclosure, a computer-readable storage medium having a computer program stored thereon is provided. The computer program, when executed on at least one processor, causes any of the methods according to the first or second aspects of the disclosure to be performed.

Drawings

Some example embodiments of the present disclosure will be described below with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or equivalent elements. The drawings are only for purposes of facilitating a better understanding of embodiments of the disclosure and are not necessarily drawn to scale, wherein:

fig. 1 shows a schematic diagram of an example wireless communication network in which embodiments of the present disclosure can be implemented;

fig. 2 schematically shows a channel sensing process;

FIG. 3 shows correlation results for different reference signal sequences;

fig. 4 shows a flow diagram of a method for reference signal configuration according to an embodiment of the present disclosure;

fig. 5 illustrates example operations for determining a reference signal configuration in accordance with embodiments of the present disclosure;

fig. 6 illustrates example operations for determining a reference signal configuration according to another embodiment of the present disclosure;

fig. 7 shows a flow diagram of another method for reference signal configuration according to an embodiment of the present disclosure;

fig. 8 shows a flow chart of a method at the network device side according to an embodiment of the disclosure and

fig. 9 shows a simplified block diagram of a device for use in a communication network according to an embodiment of the present disclosure.

Detailed Description

It is understood that all these embodiments in this disclosure are presented only to enable those skilled in the art to better understand and further practice the disclosure, and are not intended to limit the scope of the disclosure. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. For clarity, some features of the actual implementation described in this specification may be omitted.

References in the specification to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms "comprises," comprising, "" has, "" having, "" includes, "" including, "" has, "" having, "" contains, "" containing, "" contains, "" contain a mixture of one or more other features, elements, components, and/or combinations thereof. The term "optional" means that the embodiment or implementation being described is not mandatory, and may be omitted in some cases.

As used in this disclosure, the term "circuitry" may refer to one or more or all of the following: (a) hardware circuit implementations only (e.g., analog and/or digital circuit implementations only), (b) a combination of hardware circuits and software, and (c) hardware circuits and/or processors (such as microprocessors or portions of microprocessors) that require software (e.g., firmware) for operation, but that may not be present when software is not required for the operation. Combinations of hardware circuitry and software may include, among others, such as (as applicable): (i) a combination of analog and/or digital hardware circuitry with software/firmware, and (ii) any portion of a hardware processor with software (including a digital signal processor), software, and memory that work together to cause a device such as a mobile phone or server to perform various functions. This definition of circuitry applies to all uses of this term in this application, including any claims. As a further example, as used in this application, the term circuitry also encompasses only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also encompasses, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

Additionally, as used herein, the term "communication system" refers to a system or network that conforms to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-advanced (LTE-a), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), CDMA2000, time division synchronous code division multiple access (TD-CDMA), and the like. Further, communication between devices in a communication network may be performed according to any suitable communication protocol. For example, communication protocols include, but are not limited to, global system for mobile communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and/or other suitable communication protocols such as first generation (1G), second generation (2G), 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols, Wireless Local Area Network (WLAN) standards (such as IEEE 802.11 standards); and/or any other suitable wireless communication standard, and/or any other protocol now known or later developed in the future.

As used herein, the term "network device" refers to a device in a communication network via which a terminal device may access the network and receive services therefrom. Depending on the terminology and technology used, a network device may refer to a Base Station (BS), an Access Point (AP), and so on.

The term "communication device" refers to any device having communication capabilities. By way of example, and not limitation, a communication device may also be referred to as a terminal device, User Equipment (UE), Subscriber Station (SS), portable subscriber station, Mobile Station (MS), or Access Terminal (AT). The communication devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, tablet computers, wearable terminals, Personal Digital Assistants (PDAs), portable computers, desktop computers, image capture terminals such as digital cameras, gaming terminals, music storage and playback appliances, in-vehicle wireless terminals, wireless endpoints, mobile stations, Laptop Embedded Equipment (LEE), laptop installation equipment (LME), USB dongles, smart devices, wireless Customer Premises Equipment (CPE), device-to-device (D2D) communication devices, machine-to-machine (M2M) devices, V2X devices, and the like. In the following description, the terms "communication device," "terminal," "user equipment," and "UE" may be used interchangeably in this disclosure.

A schematic diagram of an example wireless communication system 100 in which embodiments of the present disclosure can be implemented is shown in fig. 1. The wireless communication system 100 may include one or more network devices 101. For example, in this example, network device 101 may be embodied as a Base Station (BS), e.g., an evolved node b (enb) or next generation node b (gnb). It should be understood that the network device 101 may also be embodied in other forms, such as a node b (nb), or a Base Station Subsystem (BSS), a repeater, a Remote Radio Head (RRH), an AP, etc. Network device 101 provides wireless connectivity to a plurality of

communication devices

102, 103, and 104 within its coverage area. It should be understood that the arrangement of fig. 1 is merely an example, and that the wireless communication system 100 may also include more or fewer or different communication devices or network devices.

In a wireless communication network such as that shown in fig. 1, transmissions from a network device to a communication device may be referred to as Downlink (DL) transmissions and transmissions in the opposite direction as Uplink (UL) transmissions. Additionally, the plurality of

communication devices

102 and 104 in the wireless communication network of fig. 1 may be D2D or V2X devices. This means that the

communication devices

102 and 104 can perform direct communication by using, for example, the LTE V2X side link (sildelink, hereinafter also referred to as SL) technology or the NR V2X side link technology developed by 3 GPP.

In DL, UL or SL communication, the receiving end generally needs channel information to perform detection of received data. The channel information may be estimated through measurement of a Reference Signal (RS). This means that the transmission performance of the RS affects the estimation accuracy of the channel information and the detection performance of the data. Therefore, in a communication system, it is desirable to be able to reduce the interference level on the RS.

On the other hand, due to the increase of traffic in the communication system, spectrum resources are increasingly scarce. To alleviate resource pressure, it is often allowed to schedule multiple transmissions on the same resource or to allow multiple services to use the same resource pool in a contention manner. This resource utilization leads to an increase in the interference level. In the V2X communications supported in LTE release 14/15, this interference can be caused by the mobile station autonomous resource selection mode, which can be even more severe in the 5G NR V2X application due to the increased number of supported traffic classes and required transmitted data.

V2X SL is defined in LTE release 14 to support direct communication of basic road safety services between vehicles and vehicles/pedestrians/infrastructure, e.g. exchange of vehicle status information such as location, speed and heading. In LTE release 15, the functionality of V2X SL is further enhanced by carrier aggregation, higher order modulation, etc. to support more diverse services and more stringent service requirements.

Furthermore, in LTE V2X release 14/15, multiple resource selection modes are supported. Among them, the resource (re) selection and reservation method based on channel sensing is applied in the V2X sidelink mode 4 (i.e., mobile station autonomous resource selection mode) to avoid resource selection collision as much as possible. This channel sensing procedure is based on the assumption of periodicity (e.g., 100ms) and fixed transmission bandwidth occupancy (subband basis) for V2X traffic. With the channel sensing results, the V2X UEs attempt to avoid using resources already reserved by other V2X UEs in the vicinity, thereby avoiding collision interference. The channel sensing procedure defined in LTE V2X is schematically illustrated in fig. 2.

As shown in fig. 2, in a channel sensing window 201, the UE will measure the resource pool configured in the carrier bandwidth 202 for side link transmission to determine if there are transmissions from other devices. For example, the UE may detect a data transmission (e.g., a physical side link shared channel (PSCCH)) 204 and a control signal transmission (e.g., a physical side link control channel (PSCCH))205 from another device at time instant (e.g., TTI) 203. Based on the measurements of the data transmission 204, the UE may determine a signal power from the other device (e.g., PSSCH-Reference Signal Received Power (RSRP)). In addition, based on the decoding of the control signal transmission 205, the UE may know the priority and/or resource reservation information of the transmitted data packet of the measured device.

If a packet arrives for the UE at time 206 of fig. 2, the UE determines the resources for transmission of the packet in the next resource selection window 207. Assuming that the UE determines to perform a transmission at time 208, it may select a resource for transmission that is different from the measured frequency resource 209 reserved/occupied by another device. It should be noted, however, that the UE may also choose to perform transmissions on the resource 209 even though the resource 209 has been reserved by another device, if no other free resources are available and/or if the UE's transmission priority is higher than the measured transmission priority of the other device. It follows that not all interference can be avoided by the channel sensing procedure.

In the NR framework of 3GPP release 16, it is expected that V2X will be further enhanced to support more service types and use cases with more stringent performance requirements, such as the use cases defined in TR 22.886v16.0.0 and TS 22.186 v15.3.0. As discussed in the research project (SI) of the NR V2X evaluation method, NR V2X must support more V2X traffic types, including not only periodic V2X traffic with constant packet size (or fixed pattern), but also periodic V2X traffic with varying (even random) packet sizes, and V2X traffic without any periodicity. Meanwhile, in most cases, the V2X packet size considered in NR V2X may be much larger than that considered in LTE V2X. For example, the packet sizes considered in LTE V2X include 190 bytes and 300 bytes, while the V2X packet sizes considered in NR V2X may be 2000 bytes and above. All these aspects result in that more collision disturbances have to be dealt with in NR V2X.

In addition, the inventors of the present disclosure found that the Reference Signal (RS) configuration mechanism used in LTE V2X does not guarantee a low interference level on the RS. LTE V2X SL uses Zadoff-Chu sequences as demodulation reference signal (DMRS) sequences. The UE transmits DMRS sequences on symbols used for DMRSs (also referred to as DMRS symbols) in the TTI. In particular, the V2X control channel (e.g., PSCCH) uses a fixed Zadoff-Chu sequence (where the sequence index u ═ 8) and a cyclic shift randomly selected from the set {0,3,6,9 }. For a V2X data channel (e.g., PSCCH), the index of the DMRS sequence used and the index of its cyclic shift are both determined by the Cyclic Redundancy Check (CRC) bits of the associated PSCCH. This means that even if two V2 XUEs select the same radio resources for SL transmission (e.g., one UE with higher packet priority may occupy resources already reserved by another UE with lower packet priority during channel sensing), they typically select different DMRS sequences and/or cyclic shifts. However, the inventors of the present disclosure found that selecting different DMRS sequences and/or cyclic shifts may not be sufficient to guarantee a low interference level.

The inventors of the present disclosure investigated the orthogonality of DMRS sequences with the same or different cyclic shifts in LTE V2X side links, including analyzing the correlation coefficients between all combinations of two different DMRS sequences (different sequence indices u, or the same u but with different cyclic shifts), and found that although the orthogonality of the complete DMRS sequence is usually good, the correlation coefficients between its partial sequences may be very high. For illustration, the correlation results for two different DMRS sequences are shown in fig. 3. In fig. 3, a curve 301 on the left side represents the correlation of a complete DMRS sequence of length 144 (i.e., occupying all subcarriers in 12 Physical Resource Blocks (PRBs)), and a curve 302 on the right side represents the correlation of a partial DMRS sequence of length 12 (i.e., a partial sequence of a DMRS sequence of length 144 that occupies one PRB). These two cases can be used to evaluate the impact of collision interference on the channel estimation of a radio multipath channel with low frequency selectivity and high frequency selectivity, respectively. As can be seen from fig. 3, the correlation coefficient between the partial sequences is very high, which means that in the presence of partial resource collision, collision interference may have a severe impact on the channel estimation performance.

In view of the above and other problems, a new solution for RS configuration is proposed in the present disclosure to achieve better interference suppression performance than the DMRS configuration mechanism of LTE V2X. The proposed solution can be used not only for DMRS but also for configuration of other RSs.

In some embodiments, one or more sets of RS (e.g., DMRS) sequences may be defined for each resource pool or carrier BWP used for V2X data transmission. Each set of RS sequences includes a plurality of RS sequences corresponding to a plurality of RS symbols in a Transmission Time Interval (TTI). The RS sequence may be, for example, a Gold sequence defined in NR. In some embodiments, a cyclic shift set containing a plurality of cyclic shift values may also be defined, which may be used for a set of RS sequences.

By way of example and not limitation, RS sequences in a set of RS sequences can serve as a base RS sequence, and the base RS sequence can form a usable RS sequence with a cyclic shift. That is, different RS sequences can be obtained by applying different cyclic shifts to the base RS sequence. The cyclic shift operation in time may be equivalent to a phase ramp rotation operation in frequency, i.e., p (n) ═ r (n) · e^j2πλn/PWhere r (n) denotes a base sequence, P ═ 12 denotes the number of subcarriers per PRB, λ denotes a cyclic shift value, and P (n) denotes an RS sequence obtained by cyclic shift.

However, embodiments of the present disclosure are not limited to constructing the RS with a combination of a base sequence and a cyclic shift. Alternatively, a combination of RS sequences and orthogonal cover codes can be used to determine the RS configuration for multiple symbols within one TTI. For example, different UEs may select the same RS sequence for multiple symbols within one TTI and the RS transmissions of different UEs do not interfere with each other by selecting different orthogonal cover codes applied to the RS sequences.

The RS sequences transmitted on multiple (e.g., 2) DMRS symbols within a TTI may be the same or different. This means that only one RS sequence may be included in each set of DMRS sequences for all DMRS symbols within a TTI, or that a plurality of different RS sequences may be included for a plurality of DMRS symbols within a TTI, respectively.

The length of the RS sequence is determined by the bandwidth of the resource pool (or carrier bandwidth partition). For example, each RS sequence may span all frequency resources of the (span) resource pool (or carrier bandwidth partition), i.e., all frequency resources (e.g., all subcarriers) mapped to the resource pool (or carrier bandwidth partition). After selecting an RS sequence from a set of RS sequences predetermined for a resource pool (or carrier bandwidth division), the UE will send only a portion of the selected RS sequence, i.e., a partial RS sequence corresponding to its transmission resources, on the resources used for its transmission (e.g., autonomously selected based on channel sensing or scheduled by the gNB). This is different from the conventional scheme of transmitting a complete RS sequence on a transmission resource.

In addition, in embodiments of the present disclosure, it is proposed to select an RS configuration to use, including an RS sequence, a cyclic shift, and/or an orthogonal cover code, based on the result of channel sensing to reduce interference.

To facilitate an understanding of the solution of the present disclosure, further embodiments will be described below with reference to fig. 4-9.

Fig. 4 shows a flow diagram of a method 400 for communication, according to an embodiment of the disclosure. For ease of illustration, the operations of the method 100 will be described below with reference to the communication device 102 and the communication system 100 of fig. 1, however, it should be understood that the example method may be implemented by other communication devices (e.g., the

communication devices

103, 104 of fig. 1) as well.

As shown in fig. 4, at block 410, the communication device 102 determines a resource selection mode to employ. In some embodiments, the communication system 100 may support multiple resource selection modes including, but not limited to, a mobile station autonomous resource selection mode (e.g., mode 4 in LTE V2X SL) and a network scheduled resource selection mode (e.g., mode 3 in LTE V2X SL).

In the mobile station autonomous resource selection mode, the communication device may autonomously select resources for its transmission from a pool of available resources (or carrier bandwidth partitioning). Although resource pools are used as an example in some embodiments, it should be understood that the embodiments described are equally applicable to carrier bandwidth partitioning (BWP), i.e. the "resource pools" referred to in the embodiments may be replaced by "carrier BWP".

By way of example and not limitation, the resource pool may be configured by the network device through System Information Block (SIB) signaling or dedicated signaling. In addition, in the mobile station autonomous resource selection mode, the communication device may apply channel sensing based resource (re) selection and reservation to avoid or reduce resource selection conflicts. In a network scheduled resource selection mode, unlike the mobile station autonomous resource selection mode, the communication device may request resources for its transmissions from the network, and the network device may send resource configuration information to the communication device via, for example, physical layer signaling.

At block 410, the communication device 102 may determine a resource selection mode based on configuration signaling from the network device 101. Alternatively or additionally, the communication device 102 may also implicitly determine the resource selection mode based on one or more of its service/traffic type, its own capabilities, and the attributes or requirements of the current operating band, among others.

Upon determining that the mobile-station autonomous resource selection mode is to be employed, the communication device 102 selects resources for transmission from a resource pool (or carrier BWP) based on channel sensing (otherwise known as sensing) at block 420. The resource pool (or carrier BWP) may be pre-configured by network device 101. In some embodiments, the resource pool (or carrier BWP) may be specific to a given service (e.g., V2X SL traffic).

Embodiments of the present disclosure are not limited to a particular resource selection algorithm. By way of example only, in some embodiments, the communication device 102 may select resources for its transmission based on received signal power (e.g., reference signal received power, RSRP) on the subchannels in the resource pool. For example, it may select the subchannel with the lowest RSRP. Alternatively or additionally, the communication device 102 may also determine which resources have been reserved by decoding control signals received on the respective sub-channels in channel sensing and select unreserved resources for its transmission.

In the case where the number of users sharing the resource pool is large, the communication device 102 may discover that no free resources are already available by channel sensing. In this case, the communication device 102 may determine the resource to select based on its own transmission priority and the priority of other transmissions detected. For example, the communication device 102 may select resources that are already occupied by other transmissions of lower priority. In some embodiments, in the resource selection of block 420, the communication device 102 may consider a combination of factors such as the priority of the transmitted data packet, the received signal strength, and other information that can be obtained through channel sensing.

At block 430, the communication device 102 evaluates the interference condition of the selected resource. Interference conditions may include, for example, but are not limited to: whether there is interference from other devices on the resource, the interference level, the number of interferers, the size of the interfered resource block, etc. By way of example and not limitation, the communication device 102 may evaluate an interference condition on the selected resource based on a result of channel sensing (such as a result of decoding a detected control channel). It should be noted that the operations of block 430 may be performed during the selection of a resource or after the selection of a resource.

At block 440, the communication device 102 determines RS configuration information for its transmission based on the evaluation of the interference condition. By taking the evaluation result of the interference condition into account in the process of determining the RS configuration information, the communication device 102 can reduce interference on the RS, improve channel estimation accuracy, and improve communication performance. The RS configuration information may include an RS sequence for the RS. The length of the RS sequence is determined by the bandwidth of the resource pool (or carrier BWP). For example, the communication device 102 may have selected only 1 PRB resource from a resource pool of 12 PRBs in block 420, and the length of its RS sequence still depends on 12 PRBs (i.e., 144 subcarriers). For example, the length of the RS sequence may be 144, i.e., the RS sequence is mapped to all subcarriers of the resource pool.

At block 450, the communication device 102 transmits a partial sequence of the RS sequence corresponding to the selected resource on the selected resource based on the determined RS configuration information. In the example where the resource pool size is 12 PRBs (i.e., 144 subcarriers) and the RS sequence length is 144, if the communication device 102 selects the 2 nd PRB as its transmission resource, then at block 450 the communication device will transmit a partial sequence of length 12 of the RS sequence corresponding to the second PRB. That is, if the complete RS sequence can be represented as P ═ { P1, P2, p3... P144}, then in this example the partial sequence transmitted by the communication device is P' ═ { P13, P14, … P24 }.

Compared with a scheme of constructing a complete RS sequence aiming at the selected transmission resources, the method 400 can more easily ensure the orthogonality among the RSs and obtain better interference suppression performance.

In some embodiments, one or more sets of RS sequences may be preconfigured for the resource pool. At block 440 of fig. 4, the communications device can determine a set of RS sequences for its RS from the predetermined set of RS sequences. In some embodiments, each of the predetermined set of RS sequences may include the same one reference signal sequence for transmission over multiple (e.g., 2) symbols in one TTI. In this case, only one RS sequence may be included in the set of RS sequences determined at block 440, and a partial sequence of the RS sequence corresponding to the selected resource is transmitted over a plurality of RS symbols in one TTI at block 450.

Alternatively, in another embodiment, each of the predetermined set of RS sequences includes a plurality of different RS sequences for transmission over a plurality of symbols in one TTI, respectively. Assuming that 2 RS symbols are included in one TTI, in this case, two different RS sequences may be included in the set of RS sequences determined at block 440; and partial sequences of the two RS sequences corresponding to the selected resources are transmitted over 2 RS symbols, respectively, at block 450.

Optionally, in some embodiments, the RS configuration information determined by the communication device 102 in block 440 of fig. 4 may further include at least one of a cyclic shift and an orthogonal cover code for the RS. The time domain cyclic shift may be equivalent to a frequency domain phase rotation, i.e., the time domain cyclic shift may be achieved by a frequency domain phase rotation, or vice versa. The cyclic shift (or phase rotation) and/or orthogonal cover code can improve the orthogonality of the RS together with the determined RS sequence, further reducing interference on the RS.

Embodiments of the present disclosure are not limited to determining RS configurations in any particular manner, but may be implemented using any suitable method that takes into account the results of the evaluation of the interference condition. Various embodiments for determining the RS configuration are described below for purposes of example only and not limitation.

In some embodiments, if the selected resources are evaluated as non-interfering resources, the communication device 102 may randomly select one set of RS sequences from a predetermined set of RS sequences as a set of reference signal sequences for its RSs.

Alternatively, in another embodiment, in the absence of interference on the selected resources, the communication device 102 can select the set of RS sequences with the highest priority from among a set of predetermined RS sequences as the set of RS sequences for its RSs, or the communication device 102 can give higher selection weight to the set of RS sequences with high priority when randomly selecting the set of RS sequences. In this embodiment, each of the predetermined set of RS sequences is assigned a priority. The priority may be determined, for example, by an index of the set of RS sequences or by the number of available cyclic shifts of the RS sequences in the set of RS sequences. Considering the priority of the RS sequence set in the selection helps to improve the utilization efficiency of the RS resources.

Optionally, the communication device 102 can further determine a cyclic shift and/or an orthogonal cover code for the RS. For example, to avoid potential undiscovered interference, the communication device 102 can also randomly select a cyclic shift for the RS from a predetermined set of cyclic shifts and/or randomly select an orthogonal cover code for the RS from a predetermined set of orthogonal cover codes.

The determination of the RS configuration in the absence of interference on the resources selected by the communication device 102 is illustrated below by way of a specific example. In this example, the resource pool of the NR V2X psch contains N consecutive PRBs, i.e. 12N subcarriers. And, 4 DMRS sequence sets with a length of 12N/2-6N are configured for the resource pool. For example, DMRS sequence r in DMRS sequence set with index i ═ 0,1,2,3_i(n) may be expressed as:

wherein c is_i(n) denotes a pseudo-random sequence constructed on the basis of, for example, a Gold sequence, which can be represented by a seed parameter S_iAnd (5) initializing. In this example, the DMRS sequence length is 6N, it spans the entire resource pool, and occupies all even (or odd) subcarriers in the resource pool on DMRS symbols (i.e., using a comb DRMS structure).

In this example, each set of DMRS sequences may contain one DMRS sequence, i.e., a single DMRS sequence in each set of DMRS sequences is used for different DMRS symbols in the V2X TTI. The 4 sets of DMRS sequences of the resource pool may be assigned different priorities for DMRS selection. For example, without loss of generality, it may be assumed that the lower the index i, the higher the priority of the corresponding DMRS sequence set. In addition, a set of cyclic shifts may be defined as {0,2,4,6,8,10}, where the cyclic shifts are achieved over a period of 12 subcarriers (i.e., 6 sequence elements with comb-like DMRS).

For the mobile station autonomous resource selection mode, when the communication device 102 has V2X traffic packets to send, it may select transmission resources for its SL transmission based on a channel sensing procedure. For example, communication devicesThe resource selected by the communication device 102 may contain M PRBs starting from the kth PRB in the resource pool, and the communication device 102 knows that there is no collision/interference on the selected resource based on the sensing result. In this case, the communication device 102 may select the set of DMRS sequences with the highest priority, i.e., to include r_i(0) The sequence set of DMRS sequences of (1). And, the communication device 102 may further randomly select a cyclic shift from a predefined set of cyclic shifts 0,2,4,6,8, 10. For example, cyclic shift 8 may be selected. In this case, the actual DMRS sequence used in the SL transmission of the communication device 102 may be represented as follows:

p(n)＝r(n+6K)·e^{j2π×8×2n/12},n＝0,1,…,6M-1 (2)

where the "2 n" term is used because a comb-like DMRS mapping structure is used. As can be seen from the expression of equation (2), the DMRS transmitted by the communication device on the selected resource is only a part of the complete DMRS sequence, that is, a partial sequence of 6M length corresponding to the M PRBs starting from the kth PRB.

On the other hand, if the resource selected by the communication device 102 is evaluated as an interfered resource, the communication device 102 may avoid RS collision with other devices as much as possible when determining RS configuration information. For example, the communication device 102 can select a set of RS sequences from a set of predetermined RS sequences that is the same as a set of RS sequences used by the interfering device as a set of reference signal sequences for the RS; and further selects a cyclic shift from a predetermined set of cyclic shifts that is different from the cyclic shift used by the interfering device or selects an orthogonal cover code from a predetermined set of orthogonal cover codes that is different from the orthogonal cover code used by the interfering device. In this embodiment, by selecting the same set of RS sequences as the interfering device, it is ensured that the partial RS sequences transmitted on the conflicted resources are the same. Further, by applying different cyclic shifts or orthogonal cover codes to the RS sequence, the orthogonality of the RS on the collision resources is ensured, so that interference is avoided. The RS orthogonality obtained by this embodiment will be significantly better than the partial correlation result shown by curve 302 in fig. 3, i.e. better than the partial correlation of different RS sequences.

The determination of the RS configuration in the presence of interference on the resources selected by the communication device 102 is illustrated below by another specific example. In this example, the resource pool of the NR V2X psch contains N consecutive PRBs, i.e. 12N subcarriers, and the DMRS length is set to 12N. That is, on a DMRS symbol, a DMRS sequence occupies all subcarriers in a resource pool. In addition, 4 sets of DMRS sequences are configured for the resource pool, where each set of sequences may contain one DMRS sequence, that is, the DMRS sequence is used for multiple DMRS symbols in V2X TTI. The DMRS sequence with index i (i.e., the DMRS sequence in the ith set) may be defined as follows:

wherein c is_i(n) is a pseudo-random sequence constructed based on, for example, a Gold sequence, which can be initialized by a seed parameter Si.

In addition, a set of cyclic shifts {0,1,2,3,4,. ·,10, 11} is also defined in this example, where the cyclic shifts are implemented over a period of 12 subcarriers. In the mobile station autonomous resource selection mode, when the communication device 102 has a V2X traffic packet and needs dual-layer spatial multiplexing in multiple-input multiple-output (MIMO) mode, the communication device 102 may select resources for SL transmission based on the sensing procedure. For example, the UE may select M consecutive PRBs starting with the kth PRB from a resource pool or carrier BWP. In this example, assume that the communication device 102 learns, based on channel sensing results in a previous resource selection period, that the selected resource has been reserved by another V2X UE (e.g., communication device 103 in fig. 1), and that the communication device 102 can decode the control channel of the communication device 103 and, from the decoding results, that the communication device 102 reserves DMRS sequence set 3 and cyclic shifts 3 and 9 for dual-layer data transmission.

In this case, the communication device 102 may select the DMRS signal according to the following rules. First, the communication device 102 selects the same set of DMRS sequences as the conflicting device (i.e., communication device 103), set 3; further, the communication device 102 randomly selects a cyclic shift from a predetermined set {0,1,2,3, 4.., 10,11} of cyclic shifts other than the cyclic shift that the communication device 103 has used (reserved). For example, the communication device 102 may select cyclic shifts 0 and 6 for its two-layer spatial multiplexing transmission. In this case, the DMRS sequence actually used by the communication device 102 in SL transmission may be expressed as:

p(n)＝r₃(n+12K)·e^{j2π×λ(i)×n/12},n＝0,1,…,12M-1 (4)

wherein r is₃(n) denotes an RS sequence with index 3 defined by equation (3), λ (i) denotes a cyclic shift selected by the communication device 102, and λ (0) ═ 0 and λ (1) ═ 6. As can be seen from the expression of equation (4), the communication device transmits only a part of the complete DMRS sequence, that is, a partial sequence of the DMRS sequence with a length of 12M corresponding to M PRBs starting from the kth PRB, on the selected resource.

In some scenarios, there may be more than one interference source on the resources selected by the communication device 102. In this case, the communication device 102 may first consider avoiding interference with high priority transmissions. As an example, the communication device 102 can determine its RS configuration through the example process 500 shown in fig. 5 where the selected resources are evaluated as resources with interference from multiple devices.

As shown in fig. 5, at block 510, the communication device 102 can rank a set of RS sequences used by a plurality of interfering devices (e.g.,

communication devices

103 and 104 in fig. 1) based on priorities of transmissions by the plurality of interfering devices. The priority of the interfering device may be determined by at least one of: a priority of a data packet transmitted by the device, a received signal power of the device, and a size of a resource interfered by the device. This operation enables the communication device 102 to determine the set of RS sequences and target devices that need to avoid interference.

At block 520, the communication device 102 selects as its set of RS sequences the set of highest ranked RS sequences with unused cyclic shifts and/or orthogonal cover codes; and randomly selects a cyclic shift and/or orthogonal cover code from among the unused cyclic shifts and/or orthogonal cover codes of the selected set of RS sequences in block 530. This means that the communication device 102 selects the same RS sequence as the highest ranked interfering RS sequence and applies a different cyclic shift and/or orthogonal cover code to the RS sequence than the interfering device. In this way, interference on the communication device 102 and the RS of the interfering device is cancelled.

In some communication scenarios (e.g., scenarios with a high number of interference sources), it may occur that none of the set of RS sequences participating in the ranking has unused orthogonal cover codes and/or orthogonal cover codes. An example embodiment for determining the RS configuration that may be used in this scenario is shown in fig. 6. As shown in fig. 6, where the selected resources are evaluated as resources having interference from multiple devices, the communication device 102 may rank a set of reference signal sequences used by the multiple devices based on priorities of transmissions of the multiple devices at block 610. This operation may be the same as the operation of block 510 of fig. 5. At block 620, the communication device 102 determines whether the set of reference signal sequences participating in the ranking have unused orthogonal cover codes and/or cyclic shifts. At block 630, in response to none of the sets of reference signal sequences participating in the ranking having unused cyclic shifts and/or orthogonal cover codes, the communication device 102 randomly selects one set of reference signal sequences that is not used by the interfering device from a predetermined plurality of sets of reference signal sequences, or selects a set of reference signal sequences having the highest priority from among the sets of reference signal sequences that are not used by the interfering device from the predetermined plurality of sets of reference signal sequences as its set of reference signal sequences for reference signals. At block 640, the communication device 102 further randomly selects a cyclic shift and/or orthogonal cover code for its reference signal. When the set of reference signal sequences participating in the ranking has unused cyclic shifts and/or orthogonal cover codes, the communication device 102 can determine the RS configuration using, for example, but not limited to, the operations of

blocks

520 and 530 of fig. 5.

As can be seen from the description of the above embodiments, with some embodiments of the present disclosure, a communication device may perform a sensing procedure (e.g., similar to the channel sensing procedure defined in LTE V2X SL) to select resources. And the communication device is allowed to select resources that have been reserved by other devices. That is, resources reserved by other devices may not be excluded and selected during the channel sensing process. This may occur where the packet priority of the communication device performing channel sensing is higher than the packet priority of the other device, although the PSSCH-RSRP of the other communication device may not be low. In this case, the communication device may select the same set of RS sequences as the other device and avoid interference on the RS by randomly selecting a different cyclic shift or orthogonal cover code than the other device, in accordance with some embodiments of the present disclosure. The method can improve the resource utilization rate efficiency, reduce the interference and improve the communication performance.

It should be noted that the operations of block 420 of fig. 4, block 450 of fig. 5, or fig. 6 may not be performed where the communication device 102 determines to employ the network scheduled resource selection mode. Alternatively, as shown in block 460-470 of fig. 4, the communication device 102 can receive a scheduling message from the network device and select resources for its transmission and determine RS configuration information for the RS based on the received scheduling message from the network device. The RS configuration information may include, for example, an RS sequence, a set of RS sequences, a cyclic shift for an RS sequence, an orthogonal cover code for an RS sequence, and the like. Specific examples of this scenario are described below.

In this example, the resource pool for the NR V2X psch may contain N consecutive PRBs, i.e. 12N subcarriers, and the DMRS sequences are 12N in length, which means that the DMRS sequences occupy all the subcarriers in the resource pool on the symbols used for the DMRS. The DMRS sequence may be defined, for example, as follows

Where (c) (n) is a pseudo-random sequence constructed based on, for example, a Gold sequence, which may be initialized by a seed parameter. This definition is the same as that in TS 38.211 for PUSCH DMRS without using transform precoding in sections 6.4.1.1.1 and 5.2.1.

In addition, in this example, only one set of DMRS sequences is configured for the resource pool. The set of DMRS sequences contains the same one DMRS sequence for different DMRS symbols in a V2X TTI. In addition, assume that the set of cyclic shifts is {0,1, 2.., 10,11}, where the cyclic shift is achieved over a period of 12 subcarriers (i.e., one PRB).

Upon determining that the resource selection mode to be used is a network scheduled resource selection mode, the communication device 102 may send a SL transmission scheduling request for V2X traffic packets to the network device 101 and receive a SL scheduling grant from the network device 101 (e.g., the gNB). The scheduling grant may indicate, for example: cyclic shift 3 is used and side link transmission uses consecutive M PRBs starting from the kth PRB in the resource pool. It should be understood that the scheduling grant may also include other information as desired. For example, where multiple sets of DMRS sequences are configured for a resource pool, the scheduling grant may also indicate the set of DMRS sequences for the UE.

According to the scheduling grant, the actual DMRS sequence used by the communication device 102 in SL transmission can be expressed as:

p(n)＝r(n+12K)·e^{j2π×3×n/12},n＝0,1,…,12M-1 (2)

that is, the communication device 102 transmits only a partial sequence of length 12M of the DMRS sequence on the selected resource, which corresponds to the selected resource, i.e., M consecutive PRBs starting with the kth PRB.

It should be understood that in some implementations, some embodiments of the present disclosure may be used in conjunction, as illustrated by the example flow 700 of fig. 7. For ease of description, the flow of fig. 7 is described below with reference still to the communication system 100 and the communication device 102 of fig. 1, however, it should be understood that the example method may be implemented in other communication scenarios as well.

In the example of fig. 7, the communication device 102 determines a resource selection pattern to use at block 710. If the resource selection mode of network scheduling is selected, the communication device 102 performs the operations of block 720, i.e., using the RS sequence and cyclic shift indicated by the network device 101.

If, at block 710, the communication device 102 determines to use the mobile station autonomous resource selection mode, the communication device 102 performs the operations of block 730, wherein the communication device 102 performs channel sensing based resource selection. At block 740, the communications device determines whether the selected resources conflict with other transmissions. If it is determined that there is no conflict, the communication device 102 determines the RS configuration through the operations of block 750-760, otherwise, determines the RS configuration through the operations of block 770-780.

Specifically, if it is determined that there is no collision, the communication device 102 randomly selects a set of RS sequences from a predetermined set of one or more RS sequences or selects a set of RS sequences with the highest priority for the plurality of RS symbols within the TTI in block 750. At block 760, the communication device 102 randomly selects a cyclic shift/orthogonal cover code for the selected set of RS sequences.

On the other hand, where it is determined that there is a collision, the communication device 102 selects the same set of RS sequences as used by the device causing the collision at block 770, and selects a cyclic shift/orthogonal cover code different from the cyclic shift/orthogonal cover code used by the device causing the collision at block 780.

A flow diagram of another method 800 that may be implemented at a network device is shown in fig. 8. For ease of illustration, the flow of fig. 8 is described below with reference to the communication system 100 and the network device 101 of fig. 1, although it should be understood that the example method may be implemented by other network devices as well.

In the method 800, the network device 101 determines a resource selection mode for a terminal device (e.g., the communication device 102 of fig. 1) at block 810. As previously described in connection with method 400, the resource selection mode may include, but is not limited to, a mobile station autonomous resource selection mode and a network scheduled resource selection mode. The network device 101 may determine the resource selection mode based on, for example, the traffic type of the communication device 102, the configured operating frequency band, and so on.

At block 820, in response to the determined resource selection mode being the network scheduling mode, the network device 101 transmits a scheduling message to the communication device 102. The scheduling message indicates transmission resources for the communication device 102 and RS configuration information. The RS configuration information includes an indication of the orthogonal cover code and/or cyclic shift of the RS sequence for the terminal device, and the length of the RS sequence is determined by the bandwidth of the resource pool or carrier BWP for the communication device 102. For example, in the case that the resource pool includes 144 subcarriers, the length of the RS sequence may be 144 or 144/2 ═ 72. However, as described above in connection with fig. 4-7, the length of the RS actually transmitted by the communication device is determined by its transmission resource size and may be only a partial sequence of the RS sequence.

It should be understood that the scheduling message sent by network device 101 in block 820 may also contain other information. Alternatively or additionally, the RS configuration information also includes an indication of the RS sequence for the communication device 102. However, where only a single set of RS sequences is configured for the resource pool of the communication device 102, the RS sequences need not be indicated in the scheduling message.

In some embodiments, the network device may also send an indication of the one or more sets of RS sequences to the communication device 102. The indication may be sent, for example, by system information or dedicated signaling (e.g., RRC signaling) for use by the communication device 102 in the mobile station autonomous resource selection mode to select an RS sequence to use from the indicated set or sets of RS sequences.

In still other embodiments, the network device may also send an indication of a set of cyclic shifts or a set of orthogonal cover codes to the communication device 102 to enable the communication device 102 to determine a suitable RS configuration in the mobile station autonomous resource selection mode to reduce interference.

One aspect of the disclosure also provides a communication device in a communication network. The communication device may be, for example, one of the

communication devices

102 and 104 of fig. 1. In one embodiment, the communications device comprises means for determining a resource selection mode to employ; means for selecting resources for transmission from a resource pool or BWP based on channel sensing in response to determining to employ a mobile station autonomous resource selection mode; means for evaluating an interference condition of the selected resource; and means for determining configuration information for the transmitted reference signals based on a result of the evaluation, the configuration information comprising a reference signal sequence for the reference signals, a length of the reference symbol sequence being determined by a bandwidth of the resource pool or carrier BWP; and means for transmitting a partial sequence of the reference signal sequence corresponding to the resource on the selected resource based on the configuration information.

In some embodiments, the above-mentioned apparatuses in the communication device may be respectively configured (or configured) to perform the operations of block 410 and block 450 in fig. 4, and therefore, the details are not repeated.

One aspect of the disclosure also provides a network device in a communication network. The network device may be, for example, network device 101 in fig. 1. In one embodiment, the network device comprises means for determining a resource selection mode for a terminal device; and means for sending a scheduling message to the terminal device in response to the determined resource selection mode being the network scheduling mode. Wherein the scheduling message indicates transmission resources for the terminal device and RS configuration information, and the RS configuration information comprises an indication of a cyclic shift and/or an orthogonal cover code of an RS sequence for the terminal device, and the length of the RS sequence is determined by the bandwidth of the resource pool or carrier BWP with which the terminal device is associated.

In some embodiments, the above-mentioned apparatuses in the network device may be respectively configured (or configured) to perform the operations of

block

810 and 820 in fig. 8, and therefore, the details are not repeated.

Fig. 9 shows a simplified block diagram of a device 900 for use in a communication network according to another embodiment of the present disclosure. The device may be implemented in/as a network device (e.g., network device 101 shown in fig. 1) or in/as a communication device (e.g.,

communication devices

102, 103, or 104 shown in fig. 1).

The device 900 may include one or more processors 910 (such as a data processor) and one or more memories 920 coupled to the processors 910. The device 900 may also include one or more transmitter/receivers 940 coupled to the processor 910. The memory 920 may be a non-transitory machine-readable storage medium and it may store a program or computer program product 930. The computer program (product) 930 may include instructions that, when executed on the associated processor 910, enable the apparatus 900 to operate in accordance with embodiments of the disclosure (e.g., to perform the methods 400,500,600, 700, or 800). The combination of one or more processors 910 and one or more memories 920 may form a processing component 950 suitable for implementing various embodiments of the disclosure.

Various embodiments of the disclosure may be implemented by a computer program or computer program product executable by processor 910, software, firmware, hardware, or combinations thereof.

The memory 920 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory terminal devices, magnetic memory terminal devices and systems, optical memory terminal devices and systems, fixed memory and removable memory, as non-limiting examples.

The processor 910 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples.

Example embodiments herein are described above with reference to block diagrams and flowchart illustrations of methods and apparatus. It should be understood that each block of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, respectively, can be implemented by various means including hardware, software, firmware, and combinations thereof. Hardware includes, for example, hardware circuitry and/or a processor.

For example, in some example embodiments, individual blocks of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, may be implemented in circuitry. Accordingly, an aspect of the present disclosure provides an apparatus comprising circuitry configured to perform method steps, functions, or operations according to embodiments of the present disclosure. By way of example, the apparatus may include circuitry configured to perform

blocks

410 and 450, respectively, of FIG. 4, or may include circuitry configured to perform

blocks

810 and 820, respectively, of FIG. 8.

In other example embodiments, individual blocks of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, may be implemented by computer programs or computer program products comprising computer program instructions. These computer program instructions may be loaded onto a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions which execute on the computer or other programmable data processing apparatus create means for implementing the functions specified in the flowchart block or blocks.

In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various operations described above. Examples of a carrier include a machine-readable transmission medium, a machine-readable storage medium, and the like.

Accordingly, the present disclosure also provides a machine-readable transmission medium, which may include, for example, electrical, optical, radio, acoustic, or other forms of propagated signals, such as carrier waves, infrared signals, and the like.

Another aspect of the disclosure also provides a machine-readable storage medium, such as a memory having a computer program or computer program product stored thereon. The machine-readable storage medium may include a computer-readable storage medium such as, but not limited to, a magnetic disk, magnetic tape, optical disk, phase change memory, or an electronic memory terminal device, such as Random Access Memory (RAM), Read Only Memory (ROM), flash memory device, CD-ROM, DVD, Blu-ray disk, and the like.

Further, while operations in some embodiments are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the subject matter described herein, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

It should also be understood that while some embodiments of the present disclosure have been described in conjunction with specific application scenarios, this should not be construed as limiting the spirit and scope of the present disclosure. The principles and concepts of the present disclosure may be more generally applied to any communication network, system, and scenario in which similar problems exist.

It will be appreciated by those skilled in the art that as technology advances, the inventive concept can be implemented in various ways. The above-described embodiments are given for the purpose of illustration and not limitation of the present disclosure, and it is to be understood that modifications and variations may be made without departing from the spirit and scope of the present disclosure as readily understood by those skilled in the art. Such modifications and variations are considered to be within the scope of the disclosure and the appended claims. The scope of the disclosure is defined by the appended claims.

Claims

1. An apparatus for communication, comprising:

at least one processor, and

at least one memory having computer program code stored thereon,

the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

determining a resource selection mode to be employed;

in response to determining to employ the mobile station autonomous resource selection mode,

selecting resources for transmission from a resource pool or carrier bandwidth partitioning BWP based on channel sensing;

evaluating an interference condition of the selected resource; and

determining configuration information of a reference signal for the transmission based on a result of the evaluation, the configuration information including a reference signal sequence for the reference signal, a length of the reference signal sequence being determined by the resource pool or a bandwidth of the carrier BWP; and

transmitting a partial sequence of the reference signal sequence corresponding to the resource on the selected resource based on the configuration information.

2. The apparatus of claim 1, wherein the configuration information further comprises at least one of a cyclic shift and an orthogonal cover code for the reference signal.

3. The apparatus of claim 1, wherein determining the configuration information for the transmitted reference signal comprises:

determining a set of reference signal sequences for the reference signal from a set of predetermined reference signal sequences for the resource pool or the carrier BWP.

4. The apparatus of claim 3, wherein each of the predetermined sets of reference signal sequences comprises a same one reference signal sequence for transmission over a plurality of symbols in one transmission time interval.

5. The apparatus of claim 3, wherein each of the predetermined sets of reference signal sequences comprises a plurality of different reference signal sequences for transmission over a plurality of symbols, respectively, in one transmission time interval.

6. The apparatus of claim 3, wherein determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences comprises:

in response to the selected resources being evaluated as non-interfered resources,

randomly selecting one set of reference signal sequences from the predetermined set of reference signal sequences as a set of reference signal sequences for the reference signal; or alternatively

And taking the reference signal sequence set with the highest priority in the preset reference signal sequence set as the reference signal sequence set used for the reference signal.

7. The apparatus of claim 6, wherein determining the configuration information for a reference signal further comprises:

in response to the selected resource being evaluated as an undisturbed resource, performing at least one of:

randomly selecting a cyclic shift for the reference signal from a predetermined set of cyclic shifts; and

an orthogonal cover code for the reference signal is randomly selected from a predetermined set of orthogonal cover codes.

8. The apparatus of claim 3, wherein determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences comprises:

in response to the selected resource being evaluated as an interfered resource,

selecting a set of reference signal sequences identical to a set of reference signal sequences used by an interference-producing device from the predetermined set of reference signal sequences as a set of reference signal sequences for the reference signal; and

selecting a cyclic shift for the reference signal from a predetermined set of cyclic shifts that is different from the cyclic shift used by the interfering device and/or selecting an orthogonal cover code for the reference signal from a predetermined set of orthogonal cover codes that is different from the orthogonal cover code used by the interfering device.

9. The apparatus of claim 3, wherein determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences comprises:

in response to the selected resources being evaluated as resources with interference from multiple devices,

ranking a set of reference signal sequences used by the plurality of devices based on priorities of transmissions by the plurality of devices;

selecting a set of highest ranked reference signal sequences having unused cyclic shifts and/or orthogonal cover codes as a set of reference signal sequences for the reference signal; and

randomly selecting a cyclic shift and/or orthogonal cover code from unused cyclic shifts and/or orthogonal cover codes of the selected set of reference signal sequences for the reference signal.

10. The apparatus of claim 3, wherein determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences comprises:

in response to none of the set of reference signal sequences participating in the ranking having unused cyclic shifts and/or orthogonal cover codes,

randomly selecting one reference signal sequence set which is not used by the plurality of devices from the predetermined plurality of reference signal sequence sets, or selecting a reference signal sequence set with the highest priority from the reference signal sequence sets which are not used by the plurality of devices from the predetermined plurality of reference signal sequence sets as the reference signal sequence set of the reference signal; and

randomly selecting a cyclic shift and/or an orthogonal cover code for the reference signal.

11. The apparatus of claim 9 or 10, wherein the priority of the transmission of each of the plurality of apparatuses is determined by at least one of:

a priority of the transmitted data packet;

receiving signal power; and

a size of a resource interfered by the device.

12. The apparatus of claim 1, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to:

receiving a scheduling message for the transmission from a network device in response to determining to employ a resource selection mode of network scheduling; and

based on the received scheduling message, selecting resources for the transmission and determining the configuration information for reference signals.

13. An apparatus for communication, comprising:

at least one processor, and

at least one memory having computer program code stored thereon,

determining a resource selection mode for the terminal device; and

responding to the determined resource selection mode as a network scheduling mode, and sending a scheduling message to the terminal equipment;

wherein the scheduling message indicates transmission resources for the terminal device and reference signal configuration information, and the reference signal configuration information comprises an indication of a cyclic shift and/or an orthogonal cover code for a reference signal sequence for the terminal device, and a length of the reference signal sequence is determined by a bandwidth for resource pool or carrier bandwidth partitioning with which the terminal device is associated.

14. The apparatus of claim 13, wherein the reference signal configuration information further comprises an indication of a reference signal sequence for the terminal device.

15. A method for communication, comprising:

determining a resource selection mode to be employed;

evaluating an interference condition of the selected resource; and

16. The method of claim 15, wherein the configuration information further comprises at least one of a cyclic shift and an orthogonal cover code for the reference signal.

17. The method of claim 15, wherein determining the configuration information for the transmitted reference signal comprises:

18. The method of claim 17, wherein each of the predetermined sets of reference signal sequences comprises a same one reference signal sequence for transmission over a plurality of symbols in one transmission time interval.

19. The method of claim 17, wherein each of the predetermined sets of reference signal sequences comprises a plurality of different reference signal sequences for transmission over a plurality of symbols, respectively, in one transmission time interval.

20. The method of claim 17, wherein determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences comprises:

randomly selecting one reference signal sequence set from the predetermined reference signal sequence sets as a reference signal sequence set for the reference signal; or

21. The method of claim 20, wherein determining the configuration information for a reference signal further comprises:

22. The method of claim 17, wherein determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences comprises:

in response to the selected resource being evaluated as an interfered resource,

23. The method of claim 20, wherein determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences comprises:

selecting a highest ranked set of reference signal sequences with unused cyclic shifts and/or orthogonal cover codes as a set of reference signal sequences for the reference signal; and

randomly selecting cyclic shift and/or orthogonal cover code bits from unused cyclic shift and/or orthogonal cover codes of the selected set of reference signal sequences for the reference signal.

24. The method of claim 17, wherein determining a set of reference signal sequences for the reference signal from a predetermined plurality of sets of reference signal sequences comprises:

randomly selecting one reference signal sequence set which is not used by the plurality of devices from the plurality of reference signal sequence sets, or selecting a reference signal sequence set with the highest priority from the reference signal sequence sets which are not used by the plurality of devices from the plurality of reference signal sequence sets as the reference signal sequence set of the reference signal; and

25. The method of claim 23 or 24, wherein the priority of the transmission of each of the plurality of devices is determined by at least one of:

a priority of the transmitted data packet;

receiving signal power; and

a size of a resource interfered by the device.

26. The method of claim 15, further comprising:

27. A method for communication, comprising:

determining a resource selection mode for the terminal device; and

responding to the determined resource selection mode as a network scheduling resource selection mode, and sending a scheduling message to the terminal equipment;

wherein the scheduling message indicates transmission resources for the terminal device and reference signal configuration information, and the reference signal configuration information comprises an indication of a cyclic shift and/or an orthogonal cover code of a reference signal sequence for the terminal device, and a length of the reference signal sequence is determined by a bandwidth for a resource pool or carrier bandwidth partitioning, BWP, with which the terminal device is associated.

28. The method of claim 27, wherein the reference signal configuration information further comprises an indication of a reference signal sequence for the terminal device.

29. An apparatus for communication, comprising:

means for determining a resource selection mode to employ;

means for selecting resources for transmission from a resource pool or carrier bandwidth partitioning, BWP, based on channel sensing in response to determining to employ a mobile station autonomous resource selection mode;

means for evaluating an interference condition of the selected resource; and

means for determining configuration information of a reference signal for the transmission based on a result of the evaluation, the configuration information comprising a reference signal sequence for the reference signal, a length of the reference signal sequence being determined by the resource pool or a bandwidth of the carrier BWP; and

means for transmitting a partial sequence of the reference signal sequence corresponding to the resource on the selected resource based on the configuration information.

30. An apparatus for communication, comprising:

means for determining a resource selection mode for the terminal device; and

means for sending a scheduling message to the terminal device in response to the determined resource selection mode being a network scheduling mode;

31. A computer-readable storage medium having embodied thereon a computer program which, when executed on at least one processor, causes the method of any one of claims 15-26 to be performed.

32. A computer-readable storage medium having embodied thereon a computer program which, when executed on at least one processor, causes the method according to any one of claims 27 to 28 to be performed.