WO2014205689A1

WO2014205689A1 - Method and device for transmitting discovery signal

Info

Publication number: WO2014205689A1
Application number: PCT/CN2013/078026
Authority: WO
Inventors: 张祺智
Original assignee: 华为技术有限公司
Priority date: 2013-06-26
Filing date: 2013-06-26
Publication date: 2014-12-31
Also published as: CN104488321A; CN104488321B

Abstract

Provided are a method and device for transmitting a discovery signal. The method comprises: according to a transmission position of a first user equipment in a previous discovery frame, determining a transmission position of the first UE in a current discovery frame, wherein the transmission position of the first user equipment in the current discovery frame is different from that of the first user equipment in the previous discovery frame in frequency; and if the transmission position of the first user equipment in the previous discovery frame is the same as that of a second user equipment in the previous discovery frame in time, then the transmission position of the first user equipment in the current discovery frame is different from that of the second user equipment in the current discovery frame in time; and transmitting a discovery signal on the transmission position of the first user equipment in the current discovery frame. The embodiments of the present invention alleviate the burden of the UE to transmit a discovery signal, thereby reducing the production cost of the UE.

Description

Method and apparatus for transmitting a Discovery signal

Technical field

The present invention relates to communication technologies, and more particularly to a method and apparatus for transmitting a Discovery signal. Background technique

Device to Device (D2D) communication means that the user equipment (User Equipment, UE for short) communicates directly without forwarding through the base station. In order to achieve direct communication with each other, UEs must first discover each other. Each UE needs to send a Discovery signal to let other UEs discover themselves. The Discovery signal sent by all UEs consists of some Discovery frames that occupy the same frequency band, have the same duration, and do not intersect in time. Each Discovery frame is divided into m frequency units from the frequency, m is a positive integer, i is the number of frequency units, and i is a non-negative integer less than m; each Discovery frame is divided into n time units from time, n Is a positive integer, j is the number of the time unit, and j is a non-negative integer less than n. The intersection of the i-th frequency unit and the j-th time unit is referred to as the (i, j)th frequency unit. Each UE uses only one frequency time unit in one Discovery frame. Considering the large number of UEs, m is usually not greater than n. Let the frequency unit used by a certain UE in the tth Discovery frame be (i _t , j _t ). The sequence (i., j.) (ii, ji) (i ₂ , j ₂ ) ... (i _t , jt) is a Discovery resource, called the first

The (it, jt) frequency time unit is the frequency time position of the Discovery resource in the tth frame.

Generally, the Discovery signal sent by each UE needs to be time-hopped, that is, the Discovery resource used by the UE has different frequency/time positions in each frame, so that each UE has a chance to be discovered by all other UEs.

The prior art provides a technical solution. When determining a transmission location of a UE in a current Discovery frame, the UE needs to know the frame number of the current Discovery frame and/or the initial frequency time position of the UE, according to the frame number of the current Discovery frame. / or the initial transmission location of the UE, determining the transmission location of the UE in the current frame. Therefore, it is necessary to design a special method for the UE to obtain the frame number of the current Discovery frame and/or the initial frequency time position of the Discovery resource. Thus, the complexity of the system is increased, and the burden on the UE to transmit and listen to the Discovery signal is increased. Summary of the invention

Embodiments of the present invention provide a method and apparatus for transmitting a Discovery signal, which is used to reduce the complexity of the system in the case of jumping the transmission position of the Discovery signal. In a first aspect, the embodiment of the present invention provides a method for transmitting a Discovery signal, including: determining, according to a transmission location of a first user equipment in a previous Discovery frame, a transmission location of the first UE in a current Discovery frame;

The transmission location of the first user equipment in the current Discovery frame is determined only according to the transmission location of the first user equipment in the previous Discovery frame; the transmission location of the first user equipment in the current Discovery frame is The first user equipment is on the previous

The transmission locations in the Discovery frame are different in frequency; if the transmission location of the first user equipment in the last Discovery frame is the same in time as the transmission location of the second user equipment in the previous Discovery frame, The transmission location of the first user equipment in the current Discovery frame is different in time from the transmission location of the second user equipment in the current Discovery frame;

The Discovery signal is transmitted at the transmission location of the first user equipment in the current Discovery frame.

With reference to the first aspect, in a first possible implementation manner, determining a transmission location of the first user equipment in a current Discovery frame according to a transmission location of the first user equipment in the previous Discovery frame includes:

Determining the above according to the formula (it, jt)=f(it—i, jt−i)=( ( ait-i+e ) mod m, ( ci _t —i+dj _t —i+g ) mod n ) a transmission location of the first user equipment in the current Discovery frame;

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the frequency unit of the first user equipment in the current Discovery frame The number indicating the frequency unit of the first user equipment in the previous Discovery frame, j is a non-negative integer less than n, and j _t represents the number of the time unit of the first user equipment in the current Discovery frame, The number of the time unit of the first user equipment in the previous Discovery frame; the m and the n are both positive integers, and the m is less than or equal to the n; the m is the total number of units of the Discovery frame on the frequency The n is the total number of units of the Discovery frame in time; the mod is a modulo operation symbol; Where a, c, d, e, f are integers, a and m are prime, c and n are prime, d and n are prime. With reference to the first aspect, in a second possible implementation manner, determining a transmission location of the first user equipment in a current Discovery frame according to a transmission location of the first user equipment in a previous Discovery frame, including:

According to the formula (i _t , j _t )= f(i ti, j ti)= ( ( a it-i+bj t-i+e ) mod m, (kc i _t -i+dj _t -i+ g) mod n ) , determining a frequency time position of the Discovery resource in the current Discovery frame;

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the number of the frequency unit of the Discovery resource in the current Discovery frame. Indicates the number of the frequency unit of the first user equipment in the previous Discovery frame, j is a non-negative integer less than n, and j _t represents the number of the time unit of the Discovery resource in the current Discovery frame, indicating the first The number of the time unit of the user equipment in the last Discovery frame; the m and the n are both positive integers, and the m is divisible by the n; the m is the total number of units of the Discovery frame in frequency, and the n is The total number of units of the Discovery frame in time; the mod is a modulo operation symbol;

Where a, b, c, d, e, g are integers, a and k are prime, d and k are prime, c and m are prime, ad-kbc and m are prime, gp, a X dk X b X c And m mutual prime.

With reference to the first aspect, or the first possible implementation manner of the first aspect, and the second possible implementation manner, in a third possible implementation manner, where the first user equipment is in the current location of the Discovery frame Before transmitting the Discovery signal, the method further includes:

The first user equipment detects the N Discovery frames before the current Discovery frame, and determines that the transmission location corresponding to the first user equipment is not used in the N Discovery frames before the current Discovery frame, where, Is a non-negative integer. In a second aspect, an embodiment of the present invention provides an apparatus for transmitting a Discovery signal, including: a determining module, configured to determine a transmission location of a first user equipment in a current Discovery frame in a transmission location in a previous Discovery frame; The device is disposed inside the first user equipment or the device is the first user equipment;

The transmission location of the first user equipment in the current Discovery frame is determined only according to the transmission location of the first user equipment in the previous Discovery frame; the transmission location of the first user equipment in the current Discovery frame is The transmission location of the first user equipment in the previous Discovery frame is different in frequency; if the first user equipment is on The transmission location in a Discovery frame is the same in time as the transmission location of the second user equipment in the previous Discovery frame, and the transmission location of the first user equipment in the current Discovery frame and the second user equipment are currently in the current location. The transmission locations in the Discovery frame are not the same in time;

And a transmission module, configured to transmit a Discovery signal on a transmission location of the first user equipment in a current Discovery frame.

With reference to the second aspect, in a first possible implementation, the determining module is specifically configured to use the formula (i _t , jt)=f(i “, jt—i)= ( ( ai _t _i+e ) according to the formula Mod m, ( ci "+dj "+g ) mod n ) , determining a transmission location of the first user equipment in the current Discovery frame;

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the frequency unit of the first user equipment in the current Discovery frame The number indicating the frequency unit of the first user equipment in the previous Discovery frame, j is a non-negative integer less than n, and j _t represents the number of the time unit of the first user equipment in the current Discovery frame, The first user equipment is on the previous

The number of the time unit of the Discovery frame; the m and the n are both positive integers, and the m is less than or equal to the n; the m is the total number of units of the Discovery frame on the frequency, and the n is the Discovery frame at the time The total number of units on; the mod is a modulo operation symbol;

Where a, c, d, e, f are integers, a and m are prime, c and n are prime, d and n are prime. With reference to the second aspect, in a second possible implementation manner, the determining module is specifically configured to use the formula (i _t , j _t )= f(i _t _!, j _t-1 )= ( ( ai _t _!+bj _t _!+e ) mod m, (kc i _t _!+dj _t-1 +g ) mod n ) , determining the frequency time position of the Discovery resource in the current Discovery frame;

Where a, b, c, d, e, g are integers, a and k are prime, d and k are prime, c and m are prime, Ad-kbc and m-co-prime, gp, a X dk X b X c and m.

With reference to the second aspect, or the first or the implementation of the second aspect, and the second possible implementation manner, in a third possible implementation, the detecting module is configured to be used by the first user equipment In the transmission location in the Discovery frame, before the Discovery signal is transmitted, the N Discovery frames before the current Discovery frame are detected, and the transmission location corresponding to the first user equipment in the N Discovery frames before the current Discovery frame is determined. Not used, where N is a non-negative integer.

In a third aspect, the embodiment of the present invention further provides a first user equipment, including:

a processor, configured to determine, in a transmission location in a previous Discovery frame, a transmission location of the first user equipment in the current Discovery frame;

The transmission location of the first user equipment in the current Discovery frame is determined only according to the transmission location of the first user equipment in the previous Discovery frame; the transmission location of the first user equipment in the current Discovery frame is The transmission location of the first user equipment in the previous Discovery frame is different in frequency; if the transmission location of the first user equipment in the previous Discovery frame and the transmission of the second user equipment in the previous Discovery frame If the location is the same in time, the transmission location of the first user equipment in the current Discovery frame is not the same as the transmission location of the second user equipment in the current Discovery frame;

And a transceiver, configured to transmit a Discovery signal on a transmission location of the first user equipment in a current Discovery frame.

With reference to the third aspect, in a first possible implementation, the processor is specifically configured to use the formula (i _t , j _t )=f(i ti, j ti)= ( ( ait-i+e ) mod according to the formula m, ( ci "+dj "+g ) mod n ) , determining a transmission location of the first user equipment in the current Discovery frame;

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the frequency unit of the first user equipment in the current Discovery frame The number indicating the frequency unit of the first user equipment in the previous Discovery frame, j is a non-negative integer less than n, and j _t represents the number of the time unit of the first user equipment in the current Discovery frame, The number of the time unit of the first user equipment in the previous Discovery frame; the m and the n are both positive integers, and the m is less than or equal to the n; the m is the total number of units of the Discovery frame on the frequency , the n The total number of units in the time of the Discovery frame; the mod is a modulo operation symbol; where a, c, d, e, f are integers, a and m are mutually prime, c and n are mutually prime, d and n are mutually prime . With reference to the third aspect, in a second possible implementation manner, the processor is specifically configured to use the formula (i _t , j _t )= f(i ti, j ti)= ( ( it-i+bj _t - i+e ) mod m, (kc i _t -i+dj _t -i+g ) mod n ) , determining a frequency time position of the Discovery resource in the current Discovery frame;

In combination with the third aspect, or the first and the second or the second implementation of the third aspect, the processor is further configured to transmit, at the transmission location of the first user equipment in the current Discovery frame. Before the discovery signal, the N Discovery frames before the current Discovery frame are detected, and the transmission location corresponding to the first user equipment is not used in the N Discovery frames before the current Discovery frame, where N is not Negative integer.

In the foregoing technical solution, the first UE is determined according to the transmission position of the first UE in the previous Discovery frame, and the first UE is only related to the frame number of the current Discovery frame and the initial transmission position of the Discovery resource. It is necessary to know that the first UE is in the transmission position of the previous Discovery frame, and it is not necessary to acquire the frame number of the current Discovery frame and the initial transmission position of the first UE, so that the transmission position of the first UE in the current frame can be determined, thereby reducing the system. The complexity reduces the burden on the first UE to transmit and listen to the Discovery signal. In each of the Discovery frames, if the transmission position of the first UE in the previous Discovery frame is the same as the transmission position of the second UE in the previous Discovery frame, the transmission position of the first UE in the current Discovery frame is The second UE is different in time in the transmission position of the current Discovery frame, and the transmission position of the first UE in the current Discovery frame is in the same position as the first UE. The transmission locations in the previous Discovery frame are not the same in frequency, so that the Discovery signal sent by each UE can be found by other UEs. DRAWINGS

1 is a flowchart of a method for transmitting a Discovery signal according to an embodiment of the present invention; FIG. 2A is a flow chart of another method for transmitting a Discovery signal according to an embodiment of the present invention;

2B is a schematic diagram of a Discovery frame pattern generated according to the method provided in FIG. 2A; FIG. 3A is a flow chart of another method for transmitting a Discovery signal according to an embodiment of the present invention;

FIG. 3B is a schematic diagram of a Discovery frame pattern generated according to the method provided in FIG. 3A; FIG. 4A is a schematic structural diagram of an apparatus for transmitting a Discovery signal according to an embodiment of the present invention;

FIG. 4B is a schematic structural diagram of another apparatus for transmitting a Discovery signal according to an embodiment of the present invention; FIG.

FIG. 5 is a schematic structural diagram of a first user equipment according to an embodiment of the present invention. detailed description

FIG. 1 is a flowchart of a method for transmitting a Discovery signal according to an embodiment of the present invention. The executor of this embodiment may be a UE that transmits a Discovery signal or a receiver.

The UE of the Discovery signal. As shown in FIG. 1, the method provided in this embodiment includes:

Step 11: The first UE determines, according to the transmission location of the first Discovery frame of the first UE, the transmission location of the first UE in the current Discovery frame, where the first UE meets the following conditions in the current transmission location of the Discovery frame. a and 1). The transmission location may be a frequency location of the first UE transmitting the Discovery signal.

If the first UE is a UE that sends a Discovery signal, when the previous Discovery frame finds that a certain transmission location is idle, the Discovery signal may be sent at the transmission location of the current Discovery frame. At this time, an idle transmission location of the previous Discovery frame. It is called the transmission location of the first UE in the previous Discovery frame. Before the first UE sends the Discovery signal on the current Discovery frame, the technical solution provided by the embodiment of the present invention may be adopted. A UE determines the transmission location of the first UE in the current Discovery frame at the transmission location of the previous Discovery frame. In addition, after the first Discovery frame finds that a certain transmission location is idle, the first UE may continue to detect whether the transmission position of the current UE in the current Discovery frame and the next Discovery frame is idle, and detect that the first UE is in the current Discovery frame and One

When the transmission location of the Discovery frame is idle, the first UE may also adopt the technical solution provided by the embodiment of the present invention, and determine the transmission location of the first UE in the current Discovery frame according to the transmission position of the first UE in the previous Discovery frame. After detecting that the first UE is idle at the transmission location of the at least one Discovery frame, the first UE may send a Discovery signal.

If the first UE is the UE that listens to the Discovery signal, the Discovery signal sent by the second UE is detected on a certain transmission of the previous Discovery frame, in order to continue to listen for the Discovery signal in the transmission location of the current Discovery frame, the first The UE may also use the technical solution provided by the embodiment of the present invention to determine the transmission location of the current Discovery frame of the UE according to the transmission position of the first UE in the previous Discovery frame. At this time, the first UE transmits the location of the Discovery signal sent by the second UE on the previous Discovery frame in the transmission location of the previous Discovery frame, and the first UE transmits the location of the current Discovery frame. A UE listens to the transmission location of the Discovery signal sent by other UEs in the current Discovery frame. In the embodiment of the present invention, the first UE satisfies the conditions A and B at the frequency time position of each Discovery frame. Condition A is that the transmission position of the first UE in the current Discovery frame is determined only according to the transmission position of the first UE in the previous Discovery frame. Condition B is that if the transmission location of the first UE in the last Discovery frame is the same in time as the transmission location of the second UE in the previous Discovery frame, the transmission location of the first UE in the current Discovery frame and the second UE The transmission locations in the current Discovery frame are not the same in time. That is, if two UEs transmit the Discovery signal at the same transmission position of the last Discovery frame, the two UEs transmit the Discovery signal at different transmission positions at different times on the current Discovery frame.

In order for the first UE to satisfy the above conditions in the frequency-time position of each Discovery frame, a one-to-map function f can be designed. First UE

U (i", j"), (i _t-1 , j _t-1 )), or (i _t , j _t )=f ( i", j" )

f ₄ (i", j")) Calculates the frequency position of each Discovery frame.

Preferably, the function f is expressed as: Z/mZ x Z/nZ→ Z/tnZ x Z/; Where is the component of f in frequency and the component of f in time. m is the total number of units in the frequency of the Discovery frame, and n is the total number of units in the time of the Discovery frame.

Z/mZ = f0, 1 in- indicates the total number of frequency units of the Discovery frame, and Z/llZ = {0 , ,., , - indicates the total number of time units of the Discovery frame. The symbol for the direct product operation represents the direct product of the set. ZlnZ, iG ZIr. i denotes the number of the frequency unit of the UE in the Discovery frame, and j denotes the number of the time unit of the UE in the Discovery frame.

f, if foot: if i≠, then f ₂ (i, j)≠ f ₂ ({, for all

Js Z/nZ, i Zlr, ( Zlr. Equivalent to, if the transmission position of the first UE in the last Discovery frame is the same in time as the transmission position of the second UE in the previous Discovery frame, then the first The transmission location of the UE in the current Discovery frame is different in time from the transmission location of the second UE in the current Discovery frame.

The following describes the meaning of the expression of the function f:

Let 八, B be two non-empty sets, if there is a law f, so that for each element a in A, according to the law f, there is a uniquely determined element f(a) in B corresponding to it, then f For the mapping from A to B, it is recorded as:

E.g:

f φ. ΐ) ^ (Ό,Ι)

H- a

The representation map f reflects each element in the open interval (0, 1) as its own square.

Step 12: The first UE transmits the Discovery signal at the frequency position of the current Discovery frame by the first UE. The transmitting the Discovery signal includes transmitting a Discovery signal and/or receiving a Discovery signal.

If the first UE is the UE that sends the Discovery signal, after determining that the first UE is in the frequency position of the current Discovery frame, the Discovery signal is sent by the first UE in the transmission position of the current Discovery frame. If the first UE is the UE that receives the Discovery signal, after determining that the first UE is in the frequency position of the current Discovery frame, the first UE receives the Discovery signal at the frequency position of the current Discovery frame.

Preferably, the first UE further satisfies the following condition c in the transmission location of the current Discovery frame: the transmission location of the first UE in the current Discovery frame is the previous one with the first UE. The transmission positions in the Discovery frame are different in frequency, and frequency diversity gain can be achieved. For example, the channel of UE0 to UE3 is very fading in frequency unit i=0, and UE0 can also transmit the Discovery signal on other frequency units, and UE3 can discover the Discovery signal sent by UE0 on other frequency units. In order to satisfy the frequency diversity low gain, the above function f satisfies: f\(i, j) ≠i, for all i,.

Optionally, before the transmitting, by the first UE, in the current location of the Discovery frame, before detecting the Discovery signal, detecting N Discovery frames before the current Discovery frame, and determining N Discoverys before the current Discovery frame. The transmission location corresponding to the first UE in the frame is not used, where N is a non-negative integer.

In the foregoing technical solution, the first UE is in accordance with the first time in the frequency position of the current Discovery frame.

The UE determines in the transmission location of the previous Discovery frame that, regardless of the frame number of the current Discovery frame and the initial transmission location of the Discovery resource, the first UE only needs to know the transmission location of the first UE in the previous Discovery frame, and does not need to acquire the current Discovery. The frame number of the frame and the initial transmission position of the first UE can determine the transmission position of the first UE in the current frame. Therefore, the complexity of the system is reduced, and the burden of transmitting and listening to the Discovery signal by the first UE is reduced. In each of the Discovery frames, if the transmission position of the first UE in the previous Discovery frame is the same as the transmission position of the second UE in the previous Discovery frame, the transmission position of the first UE in the current Discovery frame is The two UEs are different in time in the transmission position of the current Discovery frame, and the transmission position of the first UE in the current Discovery frame is different in frequency from the transmission position of the first UE in the previous Discovery frame, so that each UE The transmitted Discovery signal can be found by other UEs.

2A is a flow chart of another method for transmitting a Discovery signal according to an embodiment of the present invention. The executor of this embodiment may be a UE that transmits a Discovery signal or a UE that receives a Discovery signal. As shown in FIG. 2A, the method provided in this embodiment includes:

Step 21: The UE determines, according to the formula (i _t , jt fit — hj "): ( ( ai "+e ) mod m, ( ci ^+dj t-i+g ) mod n ), that the UE is in the current Discovery (discovery) ) The frequency position of the frame.

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the number of the frequency unit of the UE in the current Discovery frame, j is a non-negative integer less than n, j _t represents a number of time units of the UE in the current Discovery frame; the m and the n are both positive integers, and the m is less than or equal to the n; m is the total number of units in the frequency of the Discovery frame, and n is the total number of units in the time of the Discovery frame. Mod is a modulo operation.

Where (it-hjt-L^ UE is in the frequency position of the previous Discovery frame, (i _t , j _t ) is the frequency position of the UE in the current Discovery frame.

Where a, c, d, e, f are integers, a and m are prime, c and n are prime, d and n are prime. The function f is a mapping function, f satisfies ifi≠, then f ₂ (i,j)≠ f ₂ (i , for all js Z/nZ, ie ZlrJe Zlr. Preferably, at least one prime number p exists to achieve frequency diversity gain , p divides al, the p divides m, and the p does not divide e, so that f satisfies: fl(i, j)≠ i, for all i,.

For example, let m=n=3, let a=c=d=e=l, g=0, then (i _t , j _t )=f(i _t j _t-1 )=( (i"+ l) mod 3, (i _t-1 +j _t-1 ) mod3). The Discovery resources of the 9 UEs represented by the numbers 0, 1, and 8 are in the frequency of the Discovery frame t=0, 1, 2, 3 The position is shown in Figure 2B. As shown in Figure 2B, each Discovery frame has 3 frequency units in frequency and 3 time units in time. Each large box in Figure 2B represents a Discovery frame, which is listed as Time, frequency of behavior.

The first large box from the left in Figure 2B represents the 0th Discovery frame, the second largest box from the left in Figure 2B represents the first Discovery frame, and the third largest box from the left in Figure 2B represents the second. The Discovery frame, the fourth largest box from the left in Figure 2B represents the third Discovery frame.

Referring to the first large block from the left in FIG. 2B, the frequency position of UE0 in the 0th Discovery frame is (0, 0), and the frequency position of UE1 in the 0th Discovery frame is (0, 1), ... The frequency position of UE8 in the 0th Discovery frame is (2, 2). Referring to the second big box on the left side of FIG. 2B, the frequency position of UE0 in the first Discovery frame is (1, 0), and the frequency position of UE1 in the first Discovery frame is (1, 1), ... The frequency position of UE8 in the first Discovery frame is (0, 1). It can also be seen from 2B that different UEs have different frequency positions in each Discovery frame.

As shown in FIG. 2B, the time positions of UE0, UE3, and UE6 in the 0th Discovery frame are all in time unit 0, but on the first Discovery frame, the time position of UE0 is in time unit 0, and the time position of UE3 On time unit 1, the time position of UE6 is on time unit 2. Therefore, two or more UEs transmit the Discovery signal at the same time position of the previous Discovery frame, and on the current Discovery frame, at different time positions. Send a Discovery signal.

As shown in FIG. 2B, UE0 is on frequency unit 0 in the frequency domain of the 0th Discovery frame and on frequency unit 1 in the frequency domain of the first Discovery frame. Therefore, the frequency position of the current UE in the current Discovery frame is different from the frequency position of the second UE in the previous Discovery frame, so that the frequency diversity gain can be achieved.

Step 22: The UE transmits a Discovery signal at the frequency position of the current Discovery frame by the UE.

In this embodiment, according to the formula (i _t , j _t )=f(i _t-1 , j _t-1 )= ( (ai^+e) modm, (ci^+dj t-i+g) modn) The UE determines the time-frequency location of each Discovery frame, and the UE does not need to obtain the frame number of the current Discovery frame and the initial frequency-time position of the UE. Therefore, the burden of transmitting the Discovery signal by the UE and the production cost of the UE are alleviated.

FIG. 3A is a flow chart of another method for transmitting a Discovery signal according to an embodiment of the present invention. The executor of this embodiment may be a UE that transmits a Discovery signal or a UE that receives a Discovery signal. As shown in FIG. 3A, the method provided in this embodiment includes:

Step 31: The UE according to the formula (i _t , j _t )=f(i _t —丄, 丄)= ( (ai"+bj _t-1 +e) modm,

(kci"+dj _t-1 +g) modn) , determines the frequency position of the UE in the current Discovery frame.

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the number of the frequency unit of the UE in the current Discovery frame, j is a non-negative integer less than n, j _t represents a number of time units of the UE in the current Discovery frame; the m and the n are both positive integers, and the m divisible by the n, m=nk; m is the total number of units in the frequency of the Discovery frame, and n is the total number of units in the time of the Discovery frame. Mod is the modulo operator symbol.

Where (it-hjt-L^ UE is in the frequency position of the previous Discovery frame, (i _t , j _t ) is the frequency time position of the UE in the current Discovery frame;

Where a, b, c, d, e, g are integers, a and k are prime, d and k are prime, c and m are mutually prime, ad-kbc and m are prime, gp, aXd-kXbXc and m are mutually Prime.

The function f is a mapping function, f satisfies ifi≠, then f ₂ (i,j)≠ f ₂ (i, for all jGZ/nZ, i Zlr, ie Zlr. Preferably, at least one prime number exists for achieving frequency diversity gain p, the p is divisible by b, the p is divisible by m, the p is divisible by al, and the p is not Divide e such that f satisfies: fl(j, j)≠i, for all .

For example, let m=n=4, k=l, let a=3, b=2, c=-l, d=e=g=l, (i _t , j _t )= f(ij t_i) = ( ( 3 it-i+2 j _t _i+l ) mod 4, ( i _t -i+ j t-i+1 ) mod 4 ) .

The Discovery resources of the 16 UEs represented by the hexadecimal digits 0, 1, ..., f are located at the position of the Discovery frame t = 0, 1, 2, 3, 4 as shown in Fig. 3B. As shown in Fig. 3B, each Discovery frame has 4 frequency units in frequency and 4 time units in time. Each large box in Fig. 3B represents a Discovery frame, which is listed as time and behavior frequency.

As can be seen from Figure 3B, different UE resources are different in the frequency time position of each Discovery frame. The two UEs transmit the Discovery signal at the same time position of the previous Discovery frame, and then transmit the Discovery signal at different time positions on the current Discovery frame. Different UEs are different in the frequency position of each Discovery frame.

Step 32: The UE transmits the Discovery signal at the frequency position of the current Discovery frame by the UE.

In this embodiment, according to the formula 2: (i _t , jt)= f(i ti, j ti)= ( ( ai^+bj ^+e ) mod m, (kc i"+dj "+g ) mod n The UE determines the time-frequency location of each Discovery frame, and the UE does not need to obtain the frame number of the current Discovery frame and the initial frequency-time position of the UE. Therefore, the burden of transmitting the Discovery signal by the UE and the production cost of the UE are alleviated.

FIG. 4A is a schematic structural diagram of an apparatus for transmitting a Discovery signal according to an embodiment of the present invention. The apparatus can be used to implement the above method, and therefore, the features in the above method embodiments can be applied to the present embodiment. The device can be the first UE. As shown in FIG. 4A, the apparatus provided in this embodiment includes: a determining module 41 and a transmitting module 42.

a determining module 41, configured to determine, in a transmission location in a previous Discovery frame, a transmission location of the first UE in a current Discovery frame; the apparatus is disposed in the first UE or the apparatus is the first UE .

The transmission location of the first UE in the current Discovery frame is determined only according to the transmission location of the first UE in the previous Discovery frame; if the transmission location of the first UE in the previous Discovery frame is The transmission positions of the two UEs in the previous Discovery frame are the same in time, and the transmission position of the first UE in the current Discovery frame is different in time from the transmission position of the second UE in the current Discovery frame. Preferably, to implement the frequency diversity gain, the transmission position of the first UE in the current Discovery frame is The transmission positions of the first UE in the previous Discovery frame are different in frequency.

The transmitting module 42 is configured to transmit a Discovery signal on a transmission location of the first UE in a current Discovery frame.

Optionally, as shown in FIG. 4B, the apparatus provided in FIG. 4A may further include: a detecting module 43. a detecting module, configured to detect N Discovery frames before the current Discovery frame before transmitting the Discovery signal in the transmission position of the first UE in the current Discovery frame, and determine N before the current Discovery frame The transmission location corresponding to the first UE in the Discovery frame is not used, where N is a non-negative integer.

This embodiment can be described in the corresponding embodiment of FIG. 1, and details are not described herein again.

Optionally, the following embodiments are also present:

The determining module is specifically used for a formula

(( ai _t _ ₁₊ e ) mod m, ( ci M+dj M+g ) mod n ) , determining a transmission location of the first UE in a current Discovery frame;

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the frequency unit of the first UE in the current Discovery frame a number indicating a frequency unit of the first UE in the previous Discovery frame, j is a non-negative integer less than n, and j _t represents a number of the time unit of the first UE in the current Discovery frame, indicating the number a number of time units of a UE in a previous Discovery frame; the m and the n are both positive integers, and the m is less than or equal to the n; the m is a total number of units of the Discovery frame in frequency, the n The total number of units in the time of the Discovery frame; the mod is a modulo operation symbol;

Where a, c, d, e, f are integers, a and m are prime, c and n are prime, d and n are prime. Preferably, there is at least one prime number p, the p is divisible by a, the p is divisible by m, and the p is not divisible by e, so that the condition is met: the first UE is in the frequency position of the current Discovery frame, and the first The two UEs have different frequency in the frequency position of the previous Discovery frame, and the frequency diversity gain is realized.

This embodiment can be described in the corresponding embodiment of FIG. 2, and details are not described herein again.

Optionally, there may also be embodiments:

The determining module is specifically configured to use the formula (i _t , j _t )= f(i

( ai _t — ₁₊ bj _t — ₁₊ e ) mod m, (kc i _t _i+dj _t _i+g ) mod n ) , determining that the Discovery resource is currently The frequency position of the Discovery frame.

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the number of the frequency unit of the Discovery resource in the current Discovery frame. a number indicating a frequency unit of the first UE in the previous Discovery frame, where j is a non-negative integer less than n, and j _t represents a number of the time unit of the Discovery resource in the current Discovery frame, indicating the first UE The number of the time unit of the previous Discovery frame; the m and the n are both positive integers, and the m is divisible by the n; the m is the total number of units of the Discovery frame in frequency, and the n is a Discovery frame The total number of units in time; the mod is a modulo operation symbol;

Where a, b, c, d, e, g are integers, a and k are mutually prime, d and k are mutually prime, c and m are mutually prime, ad-kbc and m are prime.

Preferably, there is at least one prime number p, the p is divisible by b, the p is divisible by m, the p is divisible by a-1, and the p is not divisible by e, so that the frequency-time position of the first UE satisfies the following conditions: The frequency-time position of the first UE in the current Discovery frame is different from the frequency-time position of the second UE in the previous Discovery frame, and the frequency diversity gain is implemented.

This embodiment can be described in the corresponding embodiment of FIG. 3A, and details are not described herein again. In the foregoing technical solution, the first UE determines the frequency position of the current Discovery frame according to the transmission position of the first UE in the previous Discovery frame, and is independent of the initial transmission position of the frame number of the current Discovery frame and the Discovery resource, the first UE. It is only necessary to know the transmission position of the first UE in the previous Discovery frame, and it is not necessary to acquire the frame number of the current Discovery frame and the initial transmission position of the first UE, so that the transmission position of the first UE in the current frame can be determined, and therefore, the transmission is reduced. The complexity of the system reduces the burden on the first UE to transmit and listen to the Discovery signal. In each Discovery frame, if the transmission location of the first UE in the previous Discovery frame is the same in time as the transmission location of the second UE in the previous Discovery frame, the first UE is currently

The transmission location of the Discovery frame is different in time from the transmission location of the current UE in the current Discovery frame, and the transmission location of the first UE in the current Discovery frame and the transmission location of the first UE in the previous Discovery frame are in frequency. Different, so that the Discovery signal sent by each UE can be found by other UEs.

FIG. 5 is a schematic structural diagram of a first UE according to an embodiment of the present invention. The user equipment can be used to implement the foregoing method. Therefore, the features in the foregoing method embodiments can be applied to the implementation. In the example. As shown in FIG. 5, the first UE includes: a processor 51 and a transceiver 52.

The processor 51 is configured to determine, in a transmission location in the last Discovery frame, a transmission location of the first UE in the current Discovery frame;

The transmission location of the first UE in the current Discovery frame is determined only according to the transmission location of the first UE in the previous Discovery frame; the transmission location of the first UE in the current Discovery frame and the first The transmission position of a UE in the last Discovery frame is different in frequency; if the transmission position of the first UE in the previous Discovery frame is the same as the transmission position of the second UE in the previous Discovery frame, And the transmission location of the first UE in the current Discovery frame and the second UE are currently

The transmission locations in the Discovery frame are not the same in time;

The transceiver 52 is configured to transmit a Discovery signal at a transmission location of the first UE in a current Discovery frame.

Optionally, the processor is further configured to: before transmitting the Discovery signal in the transmission position of the first UE in the current Discovery frame, detecting N Discovery frames before the current Discovery frame, determining that The transmission location corresponding to the first UE in the N Discovery frames before the current Discovery frame is not used, where N is a non-negative integer.

The specific functions of the processor and the transceiver in this embodiment are described in the corresponding embodiment of FIG. 1, and details are not described herein again.

Optionally, the following embodiments are also present:

The processor is specifically configured according to a formula (i _t ,

( ( ai _t _ ₁₊ e ) mod m,

(ci M+dj M+g ) mod n ) , determining a transmission location of the first UE in a current Discovery frame;

Where t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, and i _t represents the frequency unit of the first UE in the current Discovery frame a number indicating a frequency unit of the first UE in the previous Discovery frame, j is a non-negative integer less than n, and j _t represents a number of the time unit of the first UE in the current Discovery frame, indicating the number a number of time units of a UE in a previous Discovery frame; the m and the n are both positive integers, and the m is less than or equal to the n; the m is a total number of units of the Discovery frame in frequency, the n The total number of units in the time of the Discovery frame; the mod is a modulo operation symbol; Where a, c, d, e, f are integers, a and m are prime, c and n are prime, d and n are prime. Preferably, there is at least one prime number p, the p is divisible by a, the p is divisible by m, and the p is not divisible by e.

The description is in the example and will not be described here.

The processor is specifically configured according to the formula (i _t , j _t )= f(i _t -i, j ti)= ( ( ai _t _ ₁₊ bj _t _ ₁₊ e ) mod m, (kc i _t _i+dj _t -i+g ) mod n ) , determining a frequency time position of the Discovery resource in the current Discovery frame;

Where a, b, c, d, e, g are integers, a and k are prime, d and k are prime, c and m are prime, ad-kbc and m are prime. Preferably, there is at least one prime p, the p is divisible b, the p is divisible by m, the p is divisible by a-1, and the p is not divisible by e.

This embodiment can be described in the corresponding embodiment of FIG. 3A, and details are not described herein again.

In the foregoing technical solution, the first UE is determined according to the transmission position of the first UE in the previous Discovery frame, and the first UE is only related to the frame number of the current Discovery frame and the initial transmission position of the Discovery resource. It is necessary to know that the first UE is in the transmission position of the previous Discovery frame, and it is not necessary to acquire the frame number of the current Discovery frame and the initial transmission position of the first UE, so that the transmission position of the first UE in the current frame can be determined, thereby reducing the system. The complexity reduces the burden on the first UE to transmit and listen to the Discovery signal. In each of the Discovery frames, if the transmission position of the first UE in the previous Discovery frame is the same as the transmission position of the second UE in the previous Discovery frame, the transmission position of the first UE in the current Discovery frame is The second UE is different in time in the transmission position of the current Discovery frame, and the transmission position of the first UE in the current Discovery frame is in the same position as the first UE. The transmission locations in the previous Discovery frame are not the same in frequency, so that the Discovery signal sent by each UE can be found by other UEs.

One of ordinary skill in the art will appreciate that all or part of the steps to implement the various method embodiments described above can be accomplished by hardware associated with the program instructions. The aforementioned program can be stored in a computer readable storage medium. The program, when executed, performs the steps including the above method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

It should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

claims

1. A method of transmitting a Discovery signal, characterized by comprising: determining the transmission position of the first UE in the current Discovery frame based on the transmission position of the first user equipment in the previous Discovery frame;

Wherein, the transmission position of the first user equipment in the current Discovery frame is determined only based on the transmission position of the first user equipment in the previous Discovery frame; the transmission position of the first user equipment in the current Discovery frame is the same as The first user equipment is in the previous

The transmission positions in the Discovery frame are different in frequency; if the transmission position of the first user equipment in the previous Discovery frame is the same in time as the transmission position of the second user equipment in the previous Discovery frame, then the The transmission position of the first user equipment in the current Discovery frame is different in time from the transmission position of the second user equipment in the current Discovery frame;

At the transmission position of the first user equipment in the current Discovery frame, transmit

Discovery signal.

2. The method according to claim 1, characterized in that, according to the transmission position of the first user equipment in the previous Discovery frame, it is determined that the first user equipment is in the current

The transmission position in the Discovery frame, including:

According to the formula (it, jt)=f(i ", jt—i)= ( ( ait-i+e ) mod m, ( ci _t -i+dj _t -i+g ) mod n ), determine the The transmission position of the user equipment in the current Discovery frame;

Among them, t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, i _t represents the frequency unit of the first user equipment in the current Discovery frame represents the number of the first user equipment in the frequency unit of the previous Discovery frame, j is a non-negative integer less than n, j _t represents the number of the first user equipment in the time unit of the current Discovery frame, represents The first user equipment is in the previous

The number of the time unit of the Discovery frame; the m and the n are both positive integers, and the m is less than or equal to the n; the m is the total number of units of the Discovery frame in frequency, and the n is the Discovery frame in time The total number of units on; The mod is the modulo operation symbol;

Among them, a, c, d, e, f are integers, a and m are relatively prime, c and n are relatively prime, and d and n are relatively prime.

3. The method according to claim 2, characterized in that there is at least one prime number p, said p divides a-l, said p divides m, and p does not divide e.

4. The method according to claim 1, characterized in that, according to the transmission position of the first user equipment in the previous Discovery frame, it is determined that the first user equipment is in the current

The transmission position in the Discovery frame, including:

According to the formula (i _t , j _t )= f(i ", j ")= ( ( a it-i+bj t-i+e ) mod m, (kc i"+dj "+g ) mod n ) , Determine the frequency and time position of the Discovery resource in the current Discovery frame;

Among them, t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, i _t represents the frequency unit number of the Discovery resource in the current Discovery frame , represents the number of the first user equipment in the frequency unit of the previous Discovery frame, j is a non-negative integer less than n, j _t represents the number of the Discovery resource in the time unit of the current Discovery frame, represents the first The number of the user equipment in the time unit of the previous Discovery frame; The m and the n are both positive integers, and the m is evenly divided by the n; The m is the total number of units in the frequency of the Discovery frame, and the n is The total number of units in time of the Discovery frame; the mod is the modulo operation symbol;

Among them, a, b, c, d, e, g are integers, a and k are mutually prime, d and k are mutually prime, c and m are mutually prime, ad-kbc and m are mutually prime, gp, a X d-k X b X c and m are relatively prime.

5. The method according to claim 4, characterized in that there is at least one prime number p, said p divides b, p divides m, p divides a-1, and p does not divide e.

6. The method according to any one of claims 1 to 5, characterized in that, before transmitting the Discovery signal at the transmission position of the first user equipment in the current Discovery frame, the method further includes:

The first user equipment detects N Discovery frames before the current Discovery frame, and determines that the transmission location corresponding to the first user equipment in the N Discovery frames before the current Discovery frame is not used, where, N is a non-negative integer.

7. A device for transmitting Discovery signals, characterized by including:

Determining module, used to determine the transmission position of the first user equipment in the current Discovery frame based on the transmission position in the previous Discovery frame; the device is provided inside the first user equipment or the device is the first user equipment User equipment;

Wherein, the transmission position of the first user equipment in the current Discovery frame is determined only based on the transmission position of the first user equipment in the previous Discovery frame; the transmission position of the first user equipment in the current Discovery frame is the same as The first user equipment is in the previous The transmission positions in the Discovery frame are different in frequency; if the transmission position of the first user equipment in the previous Discovery frame is the same in time as the transmission position of the second user equipment in the previous Discovery frame, then the The transmission position of the first user equipment in the current Discovery frame is different in time from the transmission position of the second user equipment in the current Discovery frame;

A transmission module, configured to transmit a Discovery signal at the transmission position of the first user equipment in the current Discovery frame.

8. The device according to claim 7, characterized in that the determination module is specifically used to determine according to the formula (i _t , j _t )=f (i ", j ")= ( ( ait-i+e ) mod m, ( ci _t -i+dj _t -i+g ) mod n ), determine the transmission position of the first user equipment in the current Discovery frame;

9. The device according to claim 8, characterized in that there is at least one prime number p, said p divides a-l, said p divides m, and p does not divide e.

10. The device according to claim 7, characterized in that the determination module is specifically used to determine according to the formula ( _it , _jt )=f(iti, jti)=(( _{ait_i} + bj _t _i+e ) mod m, (kc i _t _i+dj _t _i+g ) mod n ), determine the frequency-time position of the Discovery resource in the current Discovery frame;

Among them, t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, i _t represents the frequency unit number of the Discovery resource in the current Discovery frame , represents the number of the first user equipment in the frequency unit of the previous Discovery frame, j is a non-negative integer less than n, j _t represents the number of the Discovery resource in the time unit of the current Discovery frame, represents the first The number of the user equipment in the time unit of the previous Discovery frame; the m and the n are both positive integers, and the m is an even divisor of n; m is the total number of units in the Discovery frame in frequency, and n is the total number of units in the Discovery frame in time; the mod is the modulo operation sign;

11. The device according to claim 10, characterized in that there is at least one prime number p, the p is an integer division of b, the p is an integer division of m, the p is an integer division of a-1, and the p is not an integer division of e.

12. The device according to any one of claims 8 to 11, further comprising: a detection module, configured to transmit a Discovery signal at the transmission position of the first user equipment in the current Discovery frame, Detect N Discovery frames before the current Discovery frame, and determine that the transmission location corresponding to the first user equipment in the N Discovery frames before the current Discovery frame is not used, where N is a non-negative integer.

13. A first user equipment, characterized by: including:

The processor is used to determine the transmission position of the first user equipment in the current Discovery frame based on the transmission position in the previous Discovery frame;

A transceiver, configured to transmit a Discovery signal at the transmission position of the first user equipment in the current Discovery frame.

14. The user equipment according to claim 13, characterized in that the processor is specifically configured to perform according to the formula (i _t , j _t )=f (i ", j ")= ( ( ai _t _!+ e) mod m, (ci M+dj ^+g) mod n), determine the transmission position of the first user equipment in the current Discovery frame;

Among them, t is the frame number of the current Discovery frame, t-1 is the frame number of the previous Discovery frame, the i is a non-negative integer less than m, i _t represents the frequency unit of the first user equipment in the current Discovery frame The number represents the number of the first user equipment in the previous Discovery frame. The number of the frequency unit, j is a non-negative integer less than n, j _t represents the number of the first user equipment in the time unit of the current Discovery frame, represents the number of the first user equipment in the previous

15. The user equipment according to claim 14, characterized in that there is at least one prime number p, the p is an integer divisor of a-1, the p is an integer divisor of m, and the p is not an integer divisor of e.

16. The user equipment according to claim 13, characterized in that the processor is specifically configured to calculate (i _t , j _t ) = f (i t , j t ) = ( ( ai _t _i +bj _t _i+e ) mod m, (kc i _t _i+dj t-i+g ) mod n ) , determine the frequency and time position of the Discovery resource in the current Discovery frame;

Among them, a, b, c, d, e, g are integers, a and k are mutually prime, d and k are mutually prime, c and m are mutually prime, ad-kbc and m are mutually prime, gp, aX d-k X b X c and m are relatively prime.

17. The user equipment according to claim 16, characterized in that there is at least one prime number p, the p is evenly divided by b, the p is divided by m, the p is divided by a-1, and the p is not divided by e.

18. The user equipment according to any one of claims 13 to 17, characterized in that the processor is further configured to transmit a Discovery signal at the transmission position of the first user equipment in the current Discovery frame. , detect N Discovery frames before the current Discovery frame, and determine that the transmission position corresponding to the first user equipment in the N Discovery frames before the current Discovery frame is not used, where N is a non-negative integer.