WO2014179988A1 - Method and device for discovering neighbor in device-to-device communication - Google Patents

Abstract

Embodiments of the present invention provide a method and a device for discovering a neighbor in device-to-device communication. The method comprises: selecting a pilot sequence from a pilot sequence set; determining a scramble sequence corresponding to the selected pilot sequence according to a preset correspondence between each pilot sequence in the pilot sequence set and the scramble sequence; scrambling user equipment identity information by using the determined scramble sequence; and broadcasting the scrambled user equipment identity information to a neighbor by using a neighbor discovery channel. By using the embodiments of the present invention, conflict interference of multiple user equipments on pilot signals and data signals can be restrained.

Description

 Neighbor discovery method and device for device-to-device communication

 Embodiments of the present invention relate to the field of communications, and more particularly, embodiments of the present invention relate to a neighbor discovery method and apparatus for Device to Device (D2D). Background technique

 In December 2012, 3GPP launched a research project for D2D on LTE networks. The so-called D2D means that the service data is not forwarded by the base station, but the source user equipment (User Equipment, UE for short) is directly transmitted to the target user equipment through the air interface.

 D2D mainly consists of two parts: Neighbor Discovery (ND) and direct communication. Among them, neighbor discovery refers to being able to discover each other when the distance between user devices is close enough to communicate directly. Neighbor discovery is a very important step in D2D. Through this step, a user equipment can know which user equipment is nearby and has the potential for direct communication.

 Further, the neighbor discovery step is based on a user equipment broadcasting its user equipment identification information to its neighbors for discovery by its neighbors, and the user equipment accepting user equipment identification information transmitted by its multiple neighbors in order to discover its neighbors. The user equipment identification information may be transmitted in a certain sequence, for example, PSS/SSS in a Long-Term Evolution (LTE) system, and a Sounding Reference Signal (SRS). Physical Random Access Channel (PRACH). In addition, a packet-based neighbor discovery scheme may also be employed, that is, the user equipment identification information is packet-encoded. The packet-based neighbor discovery scheme can be more efficient due to the coding gain, which is for a packet-based neighbor discovery scheme.

However, in a packet-based neighbor discovery scheme, multiple user equipments contend for a neighbor discovery channel from the pool of available neighbor discovery channels. Therefore, multiple user equipments will likely select the same neighbor discovery channel to generate between the multiple user equipments. Collisions, which in turn cause collisions on the pilot and data signals, which can severely degrade the detection performance of the neighbor discovery channel. Summary of the invention

 In view of the problems existing in the prior art, embodiments of the present invention provide a method for

D2D neighbor discovery method and device.

 According to an exemplary embodiment of the present invention, a neighbor discovery method for D2D is provided. The method includes: selecting a pilot sequence from a pilot sequence set; determining a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence and the scrambling sequence in the pilot sequence set; User equipment identification information is scrambled using the determined scrambling sequence; and the scrambled user equipment identification information is broadcast to neighbors through a neighbor discovery channel.

 In one embodiment, each pilot sequence in the set of pilot sequences is bound to a scrambling sequence to determine a scrambling sequence corresponding to the selected pilot sequence.

 In another embodiment, scrambling user equipment identification information using the determined scrambling sequence includes:

 Performing cyclic redundancy calibration coding, channel coding, and rate matching on the user equipment identification information to obtain a first coding bit sequence;

 The first coded bit sequence is force-intercepted using the determined scrambling sequence as follows:

b _{; =} ς· Θ 5 _! ( ^ρ ) , ₌ 0,1,· · · ·,Α_1

Wherein the first binary element in the first coded bit sequence is represented; > the first binary element representing the seventh scrambling sequence, ρ _ε [0,1,····, Ρ - 1], where the scrambling is represented The total number of scrambling sequences in the sequence set, 7 represents the index of the determined scrambling sequence; the symbol ® represents the modulo 2 addition; the second encoded bit sequence obtained after the scrambling operation;

The second coded bit sequence is constelled to obtain a sequence of modulation symbols. Further, the total number of scrambling sequences in the set of scrambling sequences is configured by eNB signaling. Further, broadcasting, by the neighbor discovery channel, the scrambled user equipment identification information to the neighbor comprises: mapping the modulation symbol sequence to data symbols in the neighbor discovery channel.

 In still another embodiment, before selecting the pilot sequence from the pilot sequence set, the method further includes: determining a reference pilot sequence according to the physical layer cell identifier; and performing phase rotation on the reference pilot sequence to obtain a location A set of pilot sequences is described.

 According to another exemplary embodiment of the present invention, a neighbor discovery method for D2D is provided, including: receiving scrambled user equipment identification information from a neighbor; selecting a pilot sequence from a pilot sequence set; Determining a scrambling sequence corresponding to the selected pilot sequence by using a predetermined correspondence between each pilot sequence in the pilot sequence set and the scrambling sequence; and using the determined scrambling sequence for the received scrambled user The device identification information is descrambled to obtain the user equipment identification information of the neighbor.

 In one embodiment, each pilot sequence in the set of pilot sequences is bound to a scrambling sequence to determine a scrambling sequence corresponding to the selected pilot sequence.

 In another embodiment, selecting a pilot sequence from a set of pilot sequences comprises: selecting a pilot sequence from a set of pilot sequences by a hypothesis check.

 Further, the pilot sequence is selected from the pilot sequence set by a hypothesis check according to the following formula:

IQSNR _HT

Wherein _w denotes a reference pilot sequence index, t/ denotes a set formed by the serving cell of the user equipment and/or a physical layer cell identity modulo 30 of the neighboring cell, and the signal r _m (.) represents the received for the mth The pilot sequence of the channel segments, M represents the total number of neighbor discovery channel segments contained in each neighbor discovery channel, the signal _σ ² is the estimated noise power, and the parameter SNR _HT is the signal-to-noise ratio threshold in dB. Used to decide if there is a useful signal.

According to still another exemplary embodiment of the present invention, a neighbor discovery device for D2D is provided. The apparatus includes: a selecting means for selecting a pilot from a pilot sequence Determining a scrambling sequence corresponding to the selected pilot sequence with a predetermined correspondence relationship with the scrambling sequence; scrambling means for scrambling the user equipment identification information using the determined scrambling sequence; It is used to broadcast the scrambled user equipment identification information to the neighbor through the neighbor discovery channel.

 In an embodiment, the device further includes: binding means, configured to bind each pilot sequence in the pilot sequence set with a scrambling sequence to determine a corresponding pilot sequence. Scrambling sequence.

 In another embodiment, the scrambling device comprises:

 a first processing module, configured to perform cyclic redundancy check coding, channel coding, and rate matching on the user equipment identification information, to obtain a first coded bit sequence;

 a second processing module, configured to scramble the first coded bit sequence using the determined scrambling sequence according to the following formula:

b _{; =} ς· Θ 5 ) , = 0,1,· · · ·,Α_1

 Wherein the first binary element in the first coded bit sequence is represented; the first binary element representing the seventh scrambling sequence, ρ ε [0,1,····, Ρ -1], where Ρ denotes scrambling The total number of scrambling sequences in the sequence set, 7 representing the index of the determined scrambling sequence;

 The symbol ® indicates the addition of modulo 2;

 Bi denotes a second coded bit sequence obtained after the scrambling operation; and a third processing module, configured to perform constellation modulation on the second coded bit sequence to obtain a sequence of modulation symbols.

 Further, the total number of scrambling sequences in the set of scrambling sequences is configured by eNB signaling.

 Further, the broadcast apparatus includes: a mapping module, configured to map the modulation symbol sequence to data symbols in the neighbor discovery channel.

 In still another embodiment, the device further includes: second determining means, configured to determine a reference pilot sequence according to the physical layer cell identifier; and phase rotation means, configured to phase rotate the reference pilot sequence, The set of pilot sequences is obtained.

According to still another exemplary embodiment of the present invention, a neighbor for D2D is provided a discovery device, comprising: a receiving device, configured to receive scrambled user equipment identification information from a neighbor; a selecting device, configured to select a pilot sequence from a pilot sequence set; and determining means, configured to be concentrated according to the pilot sequence a predetermined correspondence between each pilot sequence and the scrambling sequence, determining a scrambling sequence corresponding to the selected pilot sequence; and descrambling means for using the determined scrambling sequence for the received scrambled user The device identification information is descrambled to obtain the user equipment identification information of the neighbor.

 In an embodiment, the device further includes: binding means, configured to bind each pilot sequence in the pilot sequence set with a scrambling sequence to determine a corresponding pilot sequence. Scrambling sequence.

 In another embodiment, the selecting means comprises: a selecting module for selecting a pilot sequence from the pilot sequence set by a hypothesis check.

Further, the selection module selects a pilot sequence from a pilot sequence set by a hypothesis check according to the following formula: p = arg max ∑∑r _m (n) . > IQSNR _HT

Wherein _w denotes a reference pilot sequence index, t/ denotes a set of the user equipment's serving cell and/or a neighboring cell's physical layer cell identity modulo 30, and the signal r _m (.) denotes the received for the mth The pilot sequence of the channel segments, M represents the total number of neighbor discovery channel segments contained in each neighbor discovery channel, the signal _σ ² is the estimated noise power, and the parameter SNR _HT is the signal-to-noise ratio threshold in dB. Used to decide if there is a useful signal.

According to still another exemplary embodiment of the present invention, a neighbor discovery device for D2D is provided. The apparatus includes: at least one processor and at least one memory including program code; the processor and the memory configured to utilize the processor such that the apparatus performs at least: selecting a pilot from a pilot sequence set Determining, according to a predetermined correspondence between each pilot sequence and the scrambling sequence in the pilot sequence set, a scrambling sequence corresponding to the selected pilot sequence; using the determined scrambling sequence to identify user equipment information Performing scrambling; and broadcasting the scrambled user equipment identification information to the neighbor through the neighbor discovery channel. According to still another exemplary embodiment of the present invention, a neighbor discovery device for D2D is provided. The apparatus includes: at least one processor and at least one memory including program code; the processor and the memory configured to utilize the processor such that the apparatus performs at least: receiving scrambling from a neighbor User equipment identification information; selecting a pilot sequence from a pilot sequence set; determining a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence and the scrambling sequence in the pilot sequence set And using the determined scrambling sequence to descramble the received scrambled user equipment identification information to obtain neighbor user equipment identification information.

 According to some embodiments of the present invention, the collision interference can be averaged and suppressed to a certain extent by the scrambling operation; meanwhile, by means of the pilot sequence set, the plurality of user equipments colliding with each other select the same pilot sequence and its corresponding The probability of the scrambling sequence is very low, which can further suppress collision interference of the plurality of user equipments on the pilot signal and the data signal. DRAWINGS

 Other features, objects, and advantages of the various embodiments of the present invention will become more apparent from the detailed description of the accompanying drawings. A flowchart of a neighbor discovery method 100 for D2D of an embodiment.

 Fig. 2 schematically shows a detailed flow chart of a neighbor discovery method 200 for D2D in accordance with one embodiment of the present invention.

 Figure 3 is a schematic flow diagram showing a neighbor discovery method 300 for D2D in accordance with one embodiment of the present invention.

 Figure 4 is a schematic block diagram showing neighbor discovery 400 for D2D in accordance with one embodiment of the present invention.

 Figure 5 is a schematic block diagram showing neighbor discovery 500 for D2D in accordance with one embodiment of the present invention.

 Figure 6 is a schematic block diagram showing a neighbor discovery 600 for D2D in accordance with another embodiment of the present invention.

Figure 7 is a schematic illustration of a neighbor for D2D in accordance with another embodiment of the present invention. The block diagram of the Discovery 700.

 Figure 8 is a schematic illustration of a missed detection likelihood result for a hypothetical check of a pilot sequence and a scrambling sequence, in accordance with one embodiment of the present invention.

 Figure 9 is a schematic illustration of the FER performance of two colliding users in accordance with another embodiment of the present invention. Detailed ways

 The embodiments of the present invention are explained and explained in more detail below with reference to the accompanying drawings. The drawings and embodiments of the present invention are to be considered as illustrative only and not limiting the scope of the invention.

 In one embodiment of the invention, the user equipment may include various types of mobile terminals, such as mobile phones, personal digital assistants (PDAs), tablets, portable computers.

 Figure 1 is a schematic flow diagram showing a neighbor discovery method 100 for D2D in accordance with one embodiment of the present invention. It should be understood that the steps of method 100 shown in Figure 1 are for illustrative purposes only and may include additional and/or alternative steps.

 The method 100 begins at step S101 and includes steps S102 through S105 as follows.

 Step S102, selecting a pilot sequence from the pilot sequence set.

 Step S103: Determine, according to a predetermined correspondence between each pilot sequence in the pilot sequence set and the scrambling sequence, a scrambling sequence corresponding to the selected pilot sequence.

 Step S104: The user equipment identification information is scrambled using the determined scrambling sequence.

 Step S105: Broadcast the scrambled user equipment identification information to the neighbor by using a neighbor discovery channel.

 Finally, method 100 ends at step S106.

It should be noted that the method 100 describes a process of how a user equipment broadcasts its user equipment identification information to its neighbors to be discovered by its neighbors. In the related art, multiple user equipments select the same neighbor discovery channel for the broadcast, resulting in The collision of the plurality of user equipments on the pilot signal and the data signal. In the embodiment of the present invention, although the plurality of user equipments still select the same neighbor discovery channel for the broadcast with a certain probability, the collision interference may be averaged and suppressed to a certain extent by the scrambling operation; meanwhile, by using the pilot In the sequence set, the probability that multiple user equipments colliding with each other select the same pilot sequence and its corresponding scrambling sequence is low, which can further suppress collision interference of the multiple user equipments on the pilot signal and the data signal.

 Furthermore, according to some embodiments of the present invention, the number of pilot sequences in the pilot sequence set in each cell, the number of scrambling sequences corresponding to the pilot sequence, and the correspondence between the pilot sequence and the scrambling sequence , can be configured by means of base station signaling, and thus learned by multiple user equipments in the cell. Furthermore, as the above number increases, the probability of multiple user equipments colliding with each other selecting the same pilot sequence and its corresponding scrambling sequence is further reduced.

 In accordance with an embodiment of the present invention, each pilot sequence in the set of pilot sequences can be bound to a scrambling sequence to determine a scrambling sequence corresponding to the selected pilot sequence. After the pilot sequence and the scrambling sequence are bound, the information of the scrambling sequence (such as the scrambling sequence index) can be implicitly propagated in the pilot sequence. Then, the neighbor receiving the scrambled user equipment identification information may obtain the information of the implicitly propagated scrambling sequence based on the pilot sequence, that is, know which scrambling sequence of the plurality of scrambling sequences is used by the user equipment. |J, the neighbor can then use the scrambling sequence to perform a descrambling operation to obtain the user equipment identification information. In this way, the neighbor can know which user equipment is in its vicinity and has the potential for direct communication, thereby selecting the user equipment for direct communication of D2D.

 The neighbor discovery method 100 for D2D shown in Fig. 1 will be described in detail below with reference to Fig. 2.

 Fig. 2 schematically shows a detailed flow chart of a neighbor discovery method 200 for D2D in accordance with one embodiment of the present invention. It should be understood that the steps of method 200 shown in Figure 2 are for illustrative purposes only and may include additional and/or alternative steps.

The method 200 comprises two main branches: a first branch consisting of steps 201 to 203 for describing operations related to a pilot sequence; a second branch consisting of steps 211 to 217 for describing a sequence associated with a scrambling sequence operating. For the sake of clarity, first describe the a branch.

 The first branch begins in step S201 and ends in step S203. Step S201 and step S202 are implemented as an independent combination, and the selection of the pilot sequence set can be implemented. The selected pilot sequence set can be used in step S102.

 In step S201, the user equipment (e.g., the user equipment described in Figure 1 that broadcasts its user equipment identification information to its neighbors for discovery by its neighbors) determines the reference pilot sequence based on the physical layer cell identity of the cell in which it is located. The physical layer cell identifier may be received in a downlink synchronization process (ie, detecting a PSS/SSS signal).

 In the LTE specification, multiple (e. g., 30) reference pilot sequences have been defined, each reference pilot sequence having a unique reference pilot sequence index, and each physical layer cell identity corresponding to a reference pilot sequence.

 Therefore, step S201 can specifically determine the reference pilot sequence by the following formula (1).

q _u (n) = e^ ^/4 , n = 0X-, Ll _{( 1 )}

Wherein, the reference pilot sequence is represented, u represents the reference pilot sequence index, L represents the reference pilot sequence length, and ^ for the 30 reference pilot sequences is listed in Table 1.

Illustrative definition of Table 1.

Generally, multiple user equipments in direct communication using D2D belong to the same cell, and therefore have the same physical layer cell identity. Therefore, by the above step S201, the plurality of user equipments can determine that the same reference pilot sequence is obtained.

For the sake of convenience, the following description is based on the case where a plurality of user equipments belong to the same cell. However, it should be noted that the present invention is not intended to limit multiple user equipments in direct communication using D2D to the same cell. Conversely, the method in the embodiment of the present invention may also be applied to multiple user equipments. The case of belonging to a neighboring cell. Specifically, it is assumed that the first user equipment and the second user equipment belong to the adjacent first cell and the second cell, respectively, and the first user equipment can learn the physical layer cell identifier of the second cell, and therefore the first user equipment The second use can be determined according to the physical layer cell identifier The reference pilot sequence used by the user equipment.

 In step S202, after determining the reference pilot sequence, orthogonal pilot sequence sets can be formed by phase rotation. Step S202 can specifically form a pilot sequence set by the following formula (2).

Qi ^P) (n) = q _u (n)e ^j2 ^ ^{n / P} , n = 0,1, ... , L _ 1 ( ₂ )

 Wherein, the reference pilot sequence is represented, M represents the reference pilot sequence index, L represents the reference pilot sequence length, p represents the phase rotation pilot sequence index, and p represents the phase rotation pilot sequence set size. For example, for the pilot sequence length of L = 6, the parameter P can be configured to 3 or 6 by eNB signaling.

 The orthogonal pilot sequence set is used for a plurality of user equipments to randomly select a pilot sequence. Generally, by using the number of pilot sequences in the pilot sequence, the plurality of user equipments colliding with each other select the same pilot sequence and corresponding The probability of the scrambling sequence is very low.

 In step S203, pilot symbols of the selected neighbor discovery channel are mapped based on the pilot sequence set. Specifically, the shaded box in Figure 2 shows the mapping.

 The second branch starts at step S211 and ends at step S217. Step S214 corresponds to step S104 in the method 100, and the user equipment identification information may be scrambled using the determined scrambling sequence.

In step S211 to step S213, the user equipment identification information bits (for example, 16 bits) are subjected to CRC coding, channel coding (for example, tail biting convolutional coding), and rate matching to obtain a first coding bit sequence, the first coding bit sequence. It can be expressed as C ₀ , d, ... C _A -i , which is fully adapted to the available data symbols in a neighbor discovery channel.

 In step S214, scrambling is performed using the first coded bit sequence and the determined scrambling sequence. The determined scrambling sequence is determined by a correspondence between a pilot sequence and a scrambling sequence. For example, the user equipment randomly selects a pilot sequence (e.g., randomly selects a pilot sequence index) in the pilot sequence formed in step S202, and then determines the scrambling sequence according to the correspondence. Specifically, the following formula can be used

(3) Performing scrambling using the first coded bit sequence and the determined scrambling sequence.

^ = 0^ ^ , 1 = 0,1, - ^ - 1 , Wherein the first binary element in the first coded bit sequence is represented; the first binary element representing the seventh scrambling sequence, ρε[0,1,···,Ρ-1], where Ρ denotes a scrambling sequence The total number of concentrated scrambling sequences, 7 representing the index of the determined scrambling sequence;

 The symbol ® indicates the addition of modulo 2;

 Bi denotes a second coded bit sequence obtained after the scrambling operation. It should be noted that the set of scrambling sequences involved in step S214 corresponds to the above-mentioned set of pilot sequences, and as described above, the scrambling sequence in the set of scrambling sequences corresponds to the pilot sequence in the pilot sequence set.

 Modulating the second coded bit sequence in steps S215 to S216

(For example, Quadrature Phase Shift Keying (QPSK)), and optionally DFT precoding based on Fourier transform, to obtain a sequence of modulation symbols.

 In step S217, the data symbols of the selected neighbor discovery channel are mapped based on the symbol sequence. Specifically, the shaded box in Figure 2 shows the mapping.

 In addition, the definition of the addition sequence can be completed based on the pseudo-random sequence generation defined in the LTE specification TS36.211 V10 (section 7.2), as follows:

s(n) = (x _l (n + N _c ) + x ₂ (n + N _c )) mod 2

x _l (n + 'i\) = (x _x (/i + 3) + x _x (/i)) mod2 (4) 2 (/i + 31) = (x ₂ (/i + 3) + x ₂ (/i + 2) + x ₂ (/i + 1) + x ₂ (n)) mod 2

Where Nc=1600, using ^θ^ΐ, ^θ, /^ΐ, υο to initialize the first m sequence, and by _Cimt = ∑ ^I ). ^2I , the multiple initialization of the second m sequence can be defined as Obtain P scrambling sequences, which are denoted as _ιη3⁄4ρ , ρ = 0,1,···, Ρ-1. FIG. 3 schematically illustrates a flow diagram of a neighbor discovery method 300 for D2D, in accordance with one embodiment of the present invention. It should be understood that the steps of method 300 shown in FIG. 3 are for illustrative purposes only and may include additional and/or alternative steps.

 The method 300 begins at step S301 and includes the following steps S302 to

S305.

 Step S302: Receive scrambled user equipment identification information from the neighbor.

Step S303, selecting a pilot sequence from the pilot sequence set. Step S304, determining, according to a predetermined correspondence between each pilot sequence and the scrambling sequence in the pilot sequence set, a scrambling sequence corresponding to the selected pilot sequence.

 Step S305: Des scrambling the received scrambled user equipment identification information by using the determined scrambling sequence to obtain neighbor user equipment identification information.

 Finally, method 300 ends at step S306.

 It should be noted that the method 300 describes a process of how a user equipment accepts user equipment identification information transmitted by multiple neighbors in order to discover its neighbors. In the related art, multiple user equipments select the same neighbor discovery channel for the broadcast with a certain probability, thereby causing collision interference of the multiple user equipments on the pilot signal and the data signal. In the embodiment of the present invention, although the plurality of user equipments still select the same neighbor discovery channel for the broadcast, the collision interference may be averaged and suppressed to a certain extent by the scrambling operation; meanwhile, by means of the pilot sequence set, The probability that multiple user equipments colliding with each other select the same pilot sequence and its corresponding scrambling sequence is low, which can further suppress collision interference of the multiple user equipments on the pilot signal and the data signal.

 In an embodiment of the invention, each pilot sequence in the set of pilot sequences can be bound to a scrambling sequence to determine a scrambling sequence corresponding to the selected pilot sequence. After the pilot sequence and the scrambling sequence are bound, the information of the scrambling sequence (such as the scrambling sequence index) can be implicitly propagated in the pilot sequence. Then, the user equipment can obtain the information of the implicitly propagated scrambling sequence based on the pilot sequence, that is, know which of the plurality of scrambling sequences is used by the neighbor, and the user equipment can then use the scrambling sequence. The sequence performs a descrambling operation to obtain user equipment identification information. In this way, the user equipment can know which user equipment is in its vicinity and has the potential for direct communication, thereby selecting the user equipment for direct communication of D2D.

According to an embodiment of the invention, selecting a pilot sequence from a set of pilot sequences comprises: selecting a pilot sequence from a set of pilot sequences by a hypothesis check. Based on the description of the foregoing step S202, the user equipment that obtains the user equipment identification information of its neighbor may select a plurality of pilot sequences obtained by phase rotation and their corresponding scrambling sequences, thereby The user equipment cannot know which scrambling sequence is used for decoding. Therefore, in the embodiment of the present invention, the face is rotated, that is, the phase is rotated. For example, the six pilot sequences and their corresponding scrambling sequences are respectively assumed, and then the correctness of the hypothesis is checked, so as to know exactly which scrambling sequence is used for decoding. Additionally or alternatively, the correct probabilities of the six pilot sequences and their corresponding scrambling sequences can be calculated separately, and then the scrambling sequences with higher probability are used for decoding.

 Further, the following formula (5) can be used by assuming that the face is from the pilot sequence set

Wherein U represents a reference pilot sequence index, U represents a set of the user equipment's serving cell and/or a neighboring cell's physical layer cell identity modulo 30, and the signal represents the received pilot sequence for the mth channel segment. M denotes the total number of neighbor discovery channel segments contained in each neighbor discovery channel, the signal ^ is the estimated noise power, and the parameter SNRHT is the signal-to-noise ratio threshold in dB for determining whether there is a useful signal.

 Based on equation (5), if the final result is an empty set, it means that the channel is found for the neighbor and there is no beacon signal for detection. Therefore, the following demodulation and decoding are avoided. Otherwise, channel estimation can be performed based on the hypothesis check result, and then the beacon signal is decoded. The scrambling sequence index is also obtained from the hypothesis check result. Figure 4 is a schematic block diagram of a neighbor discovery 400 for D2D, in accordance with one embodiment of the present invention. As shown in FIG. 4, the device 400 includes a selection device 401, a first determination device 402, a scrambling device 403, and a broadcast device 404. The selecting means 401 is configured to select a pilot sequence from the pilot sequence set. The first determining means 402 is configured to determine a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence and the scrambling sequence in the pilot sequence set. The scrambling means 403 is for scrambling the user equipment identification information using the determined scrambling sequence. The broadcaster 404 is configured to broadcast the scrambled user equipment identification information to the neighbors through the neighbor discovery channel.

In an embodiment, the device further includes: a binding device, configured to: use the pilot Each pilot sequence in the sequence set is bound to a scrambling sequence to determine a scrambling sequence corresponding to the selected pilot sequence.

 In another embodiment, the scrambling device comprises:

 a first processing module, configured to perform cyclic redundancy check coding, channel coding (such as tail biting convolutional coding), and rate matching on the user equipment identification information, to obtain a first coded bit sequence;

 a second processing module, configured to scramble the first coded bit sequence using the determined scrambling sequence according to the following formula:

b _; = c _; ten s ) J ₌ 0,l,'",A_l

 Wherein the first binary element in the first coded bit sequence is represented; the first binary element representing the seventh scrambling sequence, ρ ε [0,1,····, Ρ -1], where Ρ denotes scrambling The total number of scrambling sequences in the sequence set, 7 representing the index of the determined scrambling sequence;

 The symbol ® indicates the addition of modulo 2;

 Bi denotes a second coded bit sequence obtained after the scrambling operation; and a third processing module for modulating the second coded bit sequence to obtain a modulated symbol sequence.

 Further, the total number of scrambling sequences in the set of scrambling sequences is configured by eNB signaling.

 Further, the broadcast apparatus includes: a mapping module, configured to map the modulation symbol sequence to data symbols in the neighbor discovery channel.

In still another embodiment, the device further includes: second determining means, configured to determine a reference pilot sequence according to the physical layer cell identifier; and phase rotation means, configured to phase rotate the reference pilot sequence, The set of pilot sequences is obtained. FIG. 5 schematically illustrates a block diagram of a neighbor discovery 500 for D2D, in accordance with one embodiment of the present invention. As shown in FIG. 5, a receiving device 501, a selecting device 502, a determining device 503, and a descrambling device 504 are included. The receiving device 501 is configured to receive scrambled user equipment identification information from a neighbor. Selection means 502 for selecting from pilot sequences Select the pilot sequence. The determining means 503 is configured to determine a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence and the scrambling sequence in the pilot sequence set. The descrambling device 504 is configured to descramble the received scrambled user equipment identification information by using the determined scrambling sequence to obtain neighbor user equipment identification information.

 In an embodiment, the device further includes: binding means, configured to bind each pilot sequence in the pilot sequence set with a scrambling sequence to determine a corresponding pilot sequence. Scrambling sequence.

 In another embodiment, the selecting means comprises: a selecting module for selecting a pilot sequence from the pilot sequence set by a hypothesis check.

 Further, the selection module concentrates on the pilot sequence by assuming that the check is performed according to the following formula

IQSNR _HT

Wherein _w represents the reference pilot sequence index, t/ represents the set of the user equipment and/or the physical layer cell identity modulo 30 of the neighboring cell, and the signal r _m (.) represents the received mth. The pilot sequence of the channel segment, M represents the total number of neighbor discovery channel segments included in each neighbor discovery channel, the signal _σ ² is the estimated noise power, and the parameter SNR _HT is the signal-to-noise ratio threshold in dB. Determine if there is a useful signal. FIG. 6 schematically illustrates a block diagram of a neighbor discovery 600 for D2D in accordance with another embodiment of the present invention. As shown in FIG. 6, device 600 includes a data processor (DP) 601 and a memory (MEM) 603 coupled to data processor 601. The memory 603 stores a program (PROG) 602.

 Embodiments of the present invention may be implemented by software executed by data processor 601, or by hardware, or by a combination of software and hardware.

Memory 603 can be of any suitable type suitable for use in a local technology environment and can be implemented using any suitable data storage technology, including but not limited to semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices, and systems. Although only in Figure 6 Only one memory unit is shown, but there may be multiple physically distinct memory units in device 600. DP 601 may be of any suitable type suitable for use in a local technical environment and may include, but is not limited to, a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and one of a processor based multi-core processor architecture. Or more than one. Device 600 can include multiple processors.

 As shown in FIG. 6, the data processor 601 and the memory 603 are configured to utilize the data processor 601 such that the apparatus 600 performs at least a selection of a pilot sequence from a pilot sequence set; each of the pilot sequences according to the pilot sequence Determining a scrambling sequence corresponding to the selected pilot sequence by using a predetermined correspondence between the frequency sequence and the scrambling sequence; scrambling the user equipment identification information using the determined scrambling sequence; and scrambling the channel through the neighbor discovery channel User equipment identification information is broadcast to neighbors. Figure 7 is a schematic block diagram showing a neighbor discovery 700 for D2D in accordance with another embodiment of the present invention. As shown in FIG. 7, device 700 includes a data processor (DP) 701 and a memory (MEM) 703 coupled to data processor 701. The memory 703 stores a program (PROG) 702.

 Embodiments of the present invention may be implemented by software executed by data processor 701, or by hardware, or by a combination of software and hardware.

 Memory 703 can be of any suitable type suitable for use in a local technology environment and can be implemented using any suitable data storage technology, including but not limited to semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems. Although only one memory cell is shown in Figure 7, there may be multiple physically distinct memory cells in device 700. DP 701 may be of any suitable type suitable for use in a local technical environment and may include, but is not limited to, a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and one of a processor based multi-core processor architecture. Or more than one. Device 700 can include multiple processors.

As shown in FIG. 7, the data processor 701 and the memory 703 are configured to utilize the data processor 701 such that the device 700 performs at least the scrambled user equipment identification information from the neighbors; the pilots are selected from the pilot sequence set. Sequence; according to the pilot sequence Determining, by a predetermined correspondence between each pilot sequence and the scrambling sequence, determining a scrambling sequence corresponding to the selected pilot sequence; and performing the received scrambled user equipment identification information using the determined scrambling sequence De-scrambling, obtaining the user equipment identification information of the neighbor. The present invention also provides some simulations to evaluate the performance of the proposed invention. The simulation conditions are listed in Table 2.

 Table 2. Simulation conditions

Figure 8 is a schematic illustration of a missed detection likelihood result for a hypothesis check of a pilot sequence and a scrambling sequence, wherein P (P = 3 or 6) cyclic shift represents P phase, in accordance with one embodiment of the present invention. Rotating the pilot sequence, the cyclic shift is the result of the phase rotation in the frequency domain in the time domain.

As can be seen from Figure 8, relatively good performance is achieved using the proposed solution. For example, using the signal-to-noise ratio of ldB, the probability of missed detection is about 0.01. Also, the performance of P=3 is similar to the performance of P=6. In addition, the simulation also shows that when a useful signal is not transmitted, The probability of a false alarm in the hypothetical check is about 0.005. Figure 9 is a schematic illustration of FER performance of two collision users having the same or different pilot sequences or scrambling sequences in accordance with another embodiment of the present invention.

 It can be observed from Figure 9 that in the case of collisions, it is very important to use different pilot coding and scrambling coding to achieve good performance. It is an object of the invention to provide an efficient mechanism to implement it in a distributed manner.

 Advantages of the invention include:

 (1) Assigning and defining pilot sequences on multiple cells may enable hypothetical checking for pilot sequence/interference sequences. It can indicate if there is a useful beacon signal on the neighbor discovery channel. If it does not exist, the detection and decoding of the following beacon signals can be avoided. Therefore, the computational complexity is reduced. If present, it is assumed that the check will show which phase rotation pilot sequence is used.

 (2) The binding of the pilot sequence/scrambling sequence is implemented by the collision user using different scrambling sequences, which can greatly improve the beacon detection performance. And, the scrambling sequence index can be implicitly obtained from the applied pilot sequence.

 It should be noted that in order to make the embodiments of the present invention easier to understand, the above description omits some more specific technical details that are well known to those skilled in the art and that may be necessary for implementation of embodiments of the present invention. . Many modifications and variations are possible in the description of the invention.

 The embodiment was chosen and described in order to explain the embodiments of the invention and the embodiments of the invention It is intended to be within the scope of the invention as defined.

Claims

Claim

A neighbor discovery method for device-to-device communication, including:

 Selecting a pilot sequence from a pilot sequence set;

 Determining a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence in the pilot sequence set and the scrambling sequence;

 User equipment identification information is scrambled using the determined scrambling sequence; and the scrambled user equipment identification information is broadcast to neighbors through a neighbor discovery channel.

 2. The method of claim 1, wherein each pilot sequence in the set of pilot sequences is bound to a scrambling sequence to determine a scrambling sequence corresponding to the selected pilot sequence.

 3. The method of claim 1, wherein scrambling user equipment identification information using the determined scrambling sequence comprises:

 Performing cyclic redundancy calibration coding, channel coding, and rate matching on the user equipment identification information to obtain a first coding bit sequence;

 The first coded bit sequence is force-intercepted using the determined scrambling sequence as follows:

b _; = c _; ten s ) J ₌ 0,l,'",A_l

 Wherein the first binary element in the first coded bit sequence is represented; the first binary element representing the seventh scrambling sequence, ρ ε [0,1,····, Ρ -1], where Ρ denotes scrambling The total number of scrambling sequences in the sequence set, 7 representing the index of the determined scrambling sequence;

 The symbol ® indicates the addition of modulo 2;

 Bi denotes a second coded bit sequence obtained after the scrambling operation; constellation is performed on the second coded bit sequence to obtain a sequence of modulation symbols.

4. The method of claim 3, wherein the total number of scrambling sequences in the set of scrambling sequences is configured by eNB signaling.

5. The method of claim 3, scrambling through a neighbor discovery channel Broadcasting user equipment identification information to neighbors includes:

 Mapping the sequence of modulation symbols to data symbols in the neighbor discovery channel.

The method according to any one of claims 1 to 5, wherein before the pilot sequence is selected from the pilot sequence set, the method further includes:

 Determining a reference pilot sequence based on the physical layer cell identity;

 The reference pilot sequence is phase rotated to obtain the pilot sequence set.

 7. A neighbor discovery method for device-to-device communication, comprising:

 Receiving scrambled user equipment identification information from the neighbor;

 Selecting a pilot sequence from a pilot sequence set;

 Determining a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence in the pilot sequence set and the scrambling sequence;

 The received scrambled user equipment identification information is descrambled using the determined scrambling sequence to obtain neighbor user equipment identification information.

 8. The method of claim 7, wherein each pilot sequence in the set of pilot sequences is bound to a scrambling sequence to determine a scrambling sequence corresponding to the selected pilot sequence.

 9. The method of claim 7, wherein selecting a pilot sequence from a set of pilot sequences comprises: selecting a pilot sequence from a set of pilot sequences by a hypothetical face detection.

10. The method according to claim 9, wherein the pilot sequence is selected from the set of pilot sequences by a hypothesis check according to the following formula: p = arg max > IQSNR _HT

Wherein _w represents the reference pilot sequence index, t/ represents the set of the user equipment and/or the physical layer cell identity modulo 30 of the neighboring cell, and the signal r _m (.) represents the received mth. The pilot sequence of the channel segment, M represents the total number of neighbor discovery channel segments in each neighbor discovery channel, the signal _σ ² is the estimated noise power, and the parameter SNR _HT is the signal-to-noise ratio threshold in dB, which is used to determine Is there a useful signal?

11. A neighbor discovery device for device-to-device communication, comprising: a selecting means for selecting a pilot sequence from a pilot sequence set;

 a first determining means, configured to determine, according to a predetermined correspondence between each pilot sequence and the scrambling sequence in the pilot sequence set, a scrambling sequence corresponding to the selected pilot sequence; a scrambling device, configured to use The determined scrambling sequence adds 4 to the user equipment identification information;

 The broadcast device is configured to broadcast the scrambled user equipment identification information to the neighbor through the neighbor discovery channel.

 12. The apparatus according to claim 11, further comprising: binding means, configured to bind each pilot sequence in the pilot sequence set with a scrambling sequence to determine the selected pilot sequence Corresponding scrambling sequence.

 The device according to claim 11, wherein the scrambling device comprises: a first processing module, configured to perform cyclic redundancy calibration coding, channel coding, and rate matching on the user equipment identification information, to obtain a first Coded bit sequence

 a second processing module, configured to scramble the first coded bit sequence using the determined scrambling sequence according to the following formula:

b _; = c _; ten s ) J ₌ 0,l,'",A_l

 Wherein the first binary element in the first coded bit sequence is represented; the first binary element representing the seventh scrambling sequence, ρ ε [0,1,····, Ρ -1], where Ρ denotes scrambling The total number of scrambling sequences in the sequence set, 7 representing the index of the determined scrambling sequence;

 The symbol ® indicates the addition of modulo 2;

 Bi denotes a second coded bit sequence obtained after the scrambling operation; and a third processing module for constelling the second coded bit sequence to obtain a sequence of modulation symbols.

 14. The apparatus of claim 13, the total number of scrambling sequences in the set of scrambling sequences being configured by eNB signaling.

15. The device of claim 13, the broadcast device comprising:

a mapping module, configured to map the sequence of modulation symbols into the neighbor discovery channel Data symbol.

 The apparatus according to any one of claims 11 to 15, further comprising: second determining means, configured to determine a reference pilot sequence according to the physical layer cell identity;

 And a phase rotation device configured to phase rotate the reference pilot sequence to obtain the pilot sequence set.

 17. A neighbor discovery device for device-to-device communication, comprising:

 a receiving device, configured to receive scrambled user equipment identification information from a neighbor; and selecting means, configured to select a pilot sequence from the pilot sequence set;

 Determining means for determining a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence and the scrambling sequence in the pilot sequence set; and descrambling means for using the The determined scrambling sequence descrambles the received scrambled user equipment identification information to obtain neighbor user equipment identification information.

 18. The apparatus according to claim 17, further comprising: binding means for binding each pilot sequence in the set of pilot sequences with a scrambling sequence to determine the selected pilot sequence Corresponding scrambling sequence.

 19. The apparatus of claim 17, wherein the selecting means comprises: a selection module for selecting a pilot sequence from a set of pilot sequences by a hypothesis check.

20. The apparatus according to claim 19, wherein said selection module assumes a check from a pilot sequence p = arg max > IQSNR _HT according to the following formula

Wherein _w denotes a reference pilot sequence index, t/ denotes a set formed by the serving cell of the user equipment and/or a physical layer cell identity modulo 30 of the neighboring cell, and the signal r _m (.) represents the received for the mth The pilot sequence of the channel segments, M represents the total number of neighbor discovery channel segments contained in each neighbor discovery channel, the signal _σ ² is the estimated noise power, and the parameter SNR _HT is the signal-to-noise ratio threshold in dB. Used to decide if there is a useful signal.

21. A neighbor discovery device for device-to-device communication, comprising: At least one processor and at least one memory including program code;

 The processor and the memory are configured to utilize the processor such that the device performs at least:

 Selecting a pilot sequence from a pilot sequence set;

 Determining a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence in the pilot sequence set and the scrambling sequence;

 User equipment identification information is scrambled using the determined scrambling sequence; and the scrambled user equipment identification information is broadcast to neighbors through a neighbor discovery channel.

 22. A neighbor discovery device for device-to-device communication, comprising:

 At least one processor and at least one memory including program code;

 The processor and the memory are configured to utilize the processor such that the device performs at least:

 Receiving scrambled user equipment identification information from the neighbor;

 Selecting a pilot sequence from a pilot sequence set;

 Determining a scrambling sequence corresponding to the selected pilot sequence according to a predetermined correspondence between each pilot sequence in the pilot sequence set and the scrambling sequence;

 The received scrambled user equipment identification information is descrambled using the determined scrambling sequence to obtain neighbor user equipment identification information.