CN108282842B

CN108282842B - Method and device for accessing initial cell

Info

Publication number: CN108282842B
Application number: CN201710009733.5A
Authority: CN
Inventors: 王飞; 吴丹; 童辉
Original assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Current assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Priority date: 2017-01-06
Filing date: 2017-01-06
Publication date: 2021-04-13
Anticipated expiration: 2037-01-06
Also published as: CN108282842A

Abstract

The embodiment of the invention provides a method and a device for accessing an initial cell, wherein the method comprises the following steps: transmitting the PSS at a predetermined period; and transmitting the first SSS or the second SSS, wherein one PSS and one first SSS or second SSS which are transmitted by using the same beam form one SS block, and the cell initial access of a 5G high frequency band can be effectively supported.

Description

Method and device for accessing initial cell

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for an initial cell access method.

Background

Since a single beam formed by a 5G high-band large-scale antenna is narrow and cannot cover the whole cell, the concept of multi-beam is introduced in the design of the 5G system.

However, there is currently no method and procedure for multi-beam based initial cell access.

Disclosure of Invention

In view of the foregoing technical problems, embodiments of the present invention provide a method and an apparatus for initial cell access, which can effectively support cell initial access in a 5G high frequency band.

In a first aspect of the embodiments of the present invention, a method for initial cell access is provided, including:

transmitting the PSS at a predetermined period;

transmitting the first SSS or the second SSS, wherein one PSS and one first SSS or second SSS transmitted using the same beam constitute one SS block.

Optionally, the PSS and the first SSS or the second SSS are multiplexed in FDM or TDM fashion.

Optionally, the sequence of the first SSS indicates Beam ID and the sequence of the second SSS indicates Cell ID; or

The sequence of the first SSS indicates the Cell ID and the sequence of the second SSS indicates the Beam ID.

Optionally, with 2 times the predetermined period as a period, the PSS and the first SSs are transmitted in the SS block in the first half of the period, the PSS and the second SSs2 are transmitted in the SS block in the second half of the period, or the PSS and the second SSs are transmitted in the SS block in the first half of the period, and the PSS and the first SSs are transmitted in the SS block in the second half of the period.

Optionally, the SS block includes a location indication information to help the user identify the center frequency of the system and identify the timing information of the symbol.

Optionally, the position indication information includes information indicating a position of the SS block in a frequency domain relative to a central frequency point of the system, and/or information indicating a deviation in time relative to an SS burst set starting position.

Optionally, the method further comprises:

and transmitting the PBCH in a mode of beam scanning in the appointed time-frequency resource and the appointed beam.

Optionally, the specified time-frequency resource and the specified beam are determined according to the following information:

the difference between the starting time of PBCH transmission and the starting time of PSS transmission; or

And detecting the position of PBCH corresponding to the optimal beam identified by the PSS/SSS.

According to a second aspect of the embodiments of the present invention, there is also provided a method for initial cell access, including:

receiving a PSS transmitted by a base station in a preset period;

receiving a first SSS or a second SSS transmitted by the base station, wherein one PSS and one first SSS or second SSS transmitted by using the same beam form one SS block.

Optionally, the predetermined period is 2 times a period, the PSS and the first SSs are received in the SS block in the first half of the period, the PSS and the second SSs2 are received in the SS block in the second half of the period, or the PSS and the second SSs are received in the SS block in the first half of the period, and the PSS and the first SSs are received in the SS block in the second half of the period.

Optionally, the SS block further includes location indication information for helping a user identify a center frequency of the system and identify timing information of the symbol where the user is located.

Optionally, the PBCH is received in a beam scanning manner at the designated time-frequency resource and the designated beam.

the difference between the starting time of PBCH reception and the starting time of PSS reception; or

According to a third aspect of the embodiments of the present invention, there is also provided an apparatus for initial cell access, including:

a first transmission module for transmitting the PSS at a predetermined period;

and a second transmitting module, configured to transmit the first SSS or the second SSS, where a PSS and the first SSS or the second SSS transmitted using the same beam form an SS block.

Optionally, the apparatus further comprises:

and the third sending module is used for sending the PBCH in a mode of beam scanning on the appointed time-frequency resource and the appointed beam.

According to a fourth aspect of the embodiments of the present invention, there is also provided an apparatus for initial cell access, including:

a first receiving module, configured to receive a PSS sent by a base station at a predetermined period;

and a second receiving module, configured to receive the first SSS or the second SSS sent by the base station, where a PSS and the first SSS or the second SSS sent using the same beam form an SS block.

Optionally, the apparatus further comprises:

and the third receiving module is used for receiving the PBCH in the appointed time-frequency resource and the appointed wave beam in a wave beam scanning mode.

One of the above technical solutions has the following advantages or beneficial effects: the base station transmits the PSS in a preset period; and the base station sends the first SSS or the second SSS, wherein one PSS and one first SSS or second SSS which are sent by using the same beam form an SS block, which can effectively support the cell initial access of a 5G high frequency band, and further can effectively realize the functions of time-frequency synchronization, symbol boundary identification, 10ms frame identification, beam identification and the like.

Drawings

Fig. 1 is a schematic simulation diagram of a conventional 3GPP dual-polarized antenna array;

fig. 2 is a flowchart of a method for initial cell access according to a first embodiment of the present invention;

fig. 3 is a flowchart of a method for initial cell access according to a second embodiment of the present invention;

FIG. 4 is a schematic diagram of an SS block according to a second embodiment of the present invention;

FIG. 5 is a second schematic diagram of an SS block according to a second embodiment of the present invention;

FIG. 6 is a third schematic diagram of an SS block according to a second embodiment of the present invention;

FIG. 7 is a fourth schematic diagram of an SS block according to a second embodiment of the present invention;

fig. 8 is a block diagram of an apparatus for initiating cell access according to an embodiment of the present invention;

fig. 9 is a block diagram of an apparatus for four initial cell access according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

For a high-frequency large-scale antenna system, without loss of generality, the system can be divided into N antenna array groups (panels) with the same size, all antennas with the same polarization of each group are connected to the same digital transceiving channel through phase shifters, and therefore, for a dual-polarized antenna array, each antenna array group corresponds to two digital transceiving channels. The current simulation assumptions for 3GPP are shown in fig. 1.

Hereinafter, "SS block", "SS burst set", will be understood simply:

"SS block", which can be translated into a Synchronization Signal block, refers to a base station transmitting a Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSs) and/or a Physical Broadcast Channel (PBCH) once using a certain beam, and a terminal can receive the Primary Synchronization Signal and the Secondary Synchronization Signal using a certain beam during the time;

the SS burst can be translated into a group of synchronization information blocks, including a plurality of SS blocks, which means that a base station transmits a plurality of PSS, SSs and/or PBCH in a beam scanning manner, and a terminal can receive the SS burst by using a certain beam in the time; or the base station transmits the PSS, the SSS and/or the PBCH in a repeated manner, and the terminal may receive in a beam scanning manner during the time;

the SS burst set can be translated into a group of synchronization information block sets, including a plurality of SS bursts, which means that a base station transmits a plurality of PSS, SSs and/or PBCH in a beam scanning manner, and a terminal can receive in the beam scanning manner within the time;

suppose that the number of wave numbers used by a base station in the initial cell access phase is 32 (8 in horizontal dimension, 4 in vertical dimension, which is a baseline simulated by RAN1 at present, and there may be a few or a few in practical cases), and the number of beams used by the UE is 8 (4 in horizontal dimension, 2 in vertical dimension).

Taking the example of 60kHz subcarrier spacing for high frequency, 56 OFDM (orthogonal frequency division multiplexing) symbols are included in 1ms, and it is assumed that 1 PRB (physical resource block) includes 12 subcarriers in the frequency domain as in LTE. Assuming that NR-PSS is similar to LTE (Long Term Evolution), and occupies 72 subcarriers, i.e. 6 PRBs, about 5MHz in the frequency domain, taking the simulation assumption of RAN1 as an example now, the base station includes 4 panels, so that 4 beams can be transmitted on the same symbol in an FDM (frequency division multiplexing) manner, each beam occupies 6 PRBs, and each beam is transmitted by only one panel. Thus 4 beams require 24 PRBs in total, about 20 MHz.

In the time domain, each symbol completes scanning of 4 beams, considering base station 32 beams and terminal 8 beams, 32/4 × 8 is required to complete one complete base station and terminal combined beam scanning continuously, which is 64 symbols.

The embodiment of the invention relates to a method and a device for initial cell access in a mobile communication system, which can effectively support the initial cell access of a 5G high-frequency band and further can effectively realize the functions of time-frequency synchronization, symbol boundary identification, 10ms frame identification, beam identification and the like.

First embodiment

Referring to fig. 2, a flow of a method for initial cell access is shown, and the specific steps are as follows:

step 201, transmitting the PSS by using a preset period;

the predetermined period may be 5ms, but is not limited thereto.

Step 202, transmitting the first SSS or the second SSS, wherein one PSS and one first SSS or second SSS transmitted using the same beam constitute one SS block.

Optionally, the PSS and the first SSS or the second SSS are multiplexed in FDM or TDM (time division multiplexing).

In the present embodiment, SSS is classified into two types: a first SSS and a second SSS.

It should be noted that, in this embodiment, the order of step 201 and step 202 is not limited, for example, step 201 may be executed first, step 202 may be executed, or step 201 and step 202 may be executed simultaneously.

In this embodiment, optionally, the sequence of the first SSS indicates Beam ID (Beam identity), and the sequence of the second SSS indicates Cell ID (Cell identity); or the sequence of the first SSS indicates a Cell ID, and the sequence of the second SSS indicates a Beam ID, so that Beam identification can be effectively realized.

For example: the first SSS is transmitted using Beam31, the sequence indication Beam ID is 31, the PSS is transmitted using Beam31, the first SSS and PSS constitute one SS block (SS block type1 as shown in fig. 4). Or the second SSS is transmitted using Beam31, the sequence indicates Cell ID, the PSS is transmitted using Beam31, the first SSS and PSS constitute an SS block (SS block type2 as shown in fig. 4).

In this embodiment, optionally, 2 times of the predetermined period is one period (the predetermined period is 5ms, and then 10ms is one period), the PSS and the first SSs are transmitted in the SS block in the first half period (the first 5ms) of the period, the PSS and the second SSs2 are transmitted in the SS block in the second half period (the last 5ms) of the period, or the PSS and the second SSs are transmitted in the SS block in the first half period (the first 5ms) of the period, and the PSS and the first SSs are transmitted in the SS block in the second half period (the last 5ms) of the period.

Optionally, one method for generating the sequence of the first SSS and the second SSS is: for example, in the first 5ms, a first SSS is generated by interleaving X and Y sequences of length 31, and in the second 5ms, a second SSS is generated in the same way after X and Y are exchanged. A maximum may indicate 962 beam IDs and 962 cell IDs.

In this embodiment, optionally, the SS block includes a location indication information for helping a user identify a center frequency of the system and identify timing information (timing information) of the symbol where the user is located, see fig. 5. Symbol boundary recognition and 10ms frame recognition can be effectively realized.

Further optionally, the position indication information includes information indicating a position of the SS block in a frequency domain relative to a system center frequency point, and/or information indicating an offset in time relative to an SS burst set starting position.

In this embodiment, optionally, the method further includes: and transmitting the PBCH in a mode of beam scanning in the appointed time-frequency resource and the appointed beam.

Optionally, the specified time-frequency resource and the specified beam are determined according to the following information: the difference between the starting time of PBCH transmission and the starting time of PSS transmission; or the position of the PBCH corresponding to the optimal beam identified by the PSS/SSS is detected, that is, the PSS/SSS is detected to identify which beam or beams are the optimal beam and the corresponding beam ID, so that the position of the PBCH corresponding to the beam can be determined according to a predefined rule.

Second embodiment

Referring to fig. 3, a flow of a method for initial cell access is shown, which includes the following specific steps:

step 301, receiving a PSS transmitted by a base station in a predetermined period;

the predetermined period may be 5ms, but is not limited thereto.

Step 302, receiving a first SSS or a second SSS transmitted by the base station, where a PSS and the first SSS or the second SSS transmitted using the same beam form an SS block.

In this embodiment, optionally, the sequence of the first SSS indicates Beam ID, and the sequence of the second SSS indicates Cell ID; or the sequence of the first SSS indicates a Cell ID, and the sequence of the second SSS indicates a Beam ID.

In this embodiment, optionally, 2 times the predetermined period is a period (the predetermined period is 5ms, and then 10ms is a period), the PSS and the first SSs are received in the SS block in the first half of the period, the PSS and the second SSs2 are received in the SS block in the second half of the period, or the PSS and the second SSs are received in the SS block in the first half of the period, and the PSS and the first SSs are received in the SS block in the second half of the period.

In this embodiment, optionally, the SS block includes a location indication information to help a user identify a center frequency of the system and identify timing information of the symbol where the user is located. Further, optionally, the position indication information includes information indicating a position of the SS block in a frequency domain relative to a system center frequency point, and/or information indicating a deviation in time relative to an SS burst set starting position.

In this embodiment, optionally, the method further includes: and receiving the PBCH in a mode of beam scanning in the appointed time-frequency resource and the appointed beam. For example, the designated time-frequency resources and designated beams may be determined from the following information: the difference between the starting time of PBCH reception and the starting time of PSS reception; or detecting the position of PBCH corresponding to the optimal beam identified by the PSS/SSS.

Third embodiment

PSS is sent with a period T1 (e.g., a period of 5ms), SSS is divided into two types: SSS1 and SSS2, one PSS and one SSS1 or SSS2 transmitted using the same beam constitute one SS block, where PSS and SSS1 or SSS2 are multiplexed in FDM or TDM fashion.

In the present embodiment, the SSS1 may be referred to as a first SSS, and the SSS2 may be referred to as a second SSS.

The sequence of the SSS1 indicates Beam ID, the sequence of the SSS2 indicates Cell ID, or the sequence of the SSS2 indicates Beam ID and the sequence of the SSS1 indicates Cell ID, it should be noted that the former is assumed in the following description.

When 2 times T1 (for example, 10ms) is taken as a period, PSS and SSs1 are transmitted in the SS block in the first half period (first 5ms), PSS and SSs2 are transmitted in the SS block in the second half period (second 5ms), or PSS and SSs2 are transmitted in the SS block in the first half period, and PSS and SSs1 are transmitted in the SS block in the second half period.

One method for generating the SSS1 and SSS2 sequences is as follows: for example, in the first 5ms, SSS1 is generated by interleaving X and Y sequences of length 31, and in the last 5ms, SSS2 is generated in the same way after X and Y are swapped. A maximum may indicate 962 beam IDs and 962 cell IDs. For example, if 4 beams are transmitted on one symbol, the PSS and the SSS need to occupy 40MHz in total, if the minimum system bandwidth of the high frequency band is 40MHz, at most 4 beams FDM multiplexing can be supported on one symbol, and if the minimum system bandwidth is greater than 40MHz and the number of planes of the base station is also greater than 4, greater than 4 beams multiplexing can be supported on one symbol, as shown in fig. 4.

In this embodiment, the SS block may further include a location indication information for helping the user to identify the center frequency of the system and identify the timing information of the symbol where the user is located. This information may be used, for example, to indicate the location of the SS block in the frequency domain relative to the system center frequency point, and the offset in time relative to the SS burst set start location. As shown in examples 2 and 3 described below.

For example, the position carries a valid information bit of "01111001", where the first two bits indicate the frequency domain position and "01" indicates the topmost position of four candidate positions in the frequency domain, where the four candidate positions may be preset; the last six bits indicate positions in time, and assuming that each SS block occupies one symbol, the starting position of the SS burst set is time T, the time domain position of the SS block shown in fig. 5 is time (T +57symbol), and "57" corresponds to binary bit "111001".

For example, the position carries a valid information bit of "01111001", where the first two bits indicate the frequency domain position and "01" indicates the topmost position of four candidate positions in the frequency domain, where the four candidate positions may be preset; the last six bits indicate positions in time, and assuming that each SS block occupies 2 symbols (the information is preset), and the starting position in time of the SS burst set is time T, the time domain position of the SS block shown in fig. 6 is time (T +57 × 2 symbols), and "57" corresponds to binary bit "111001".

In this embodiment, the base station transmits the PBCH by using a beam scanning method, and which beam is used to transmit the PBCH on which time-frequency resources can be obtained by the following information:

1. the difference between the PBCH transmission start time and the PSS transmission start time (this information is predefined);

2. by detecting the PSS/SSS, it is identified which beam or beams is/are the optimal beam and the corresponding beam ID, so that the location of the PBCH corresponding to the beam can be determined according to predefined rules.

For example, the base station uses 4 panels and 32 beams, the terminal uses 8 beams, and one symbol supports 4 beam FDM multiplexing, there is a preset relationship between the starting position of PBCH and the starting position of PSS/SSS2, for example, the offset is X symbols, and PBCH of one beam occupies Y symbols. For example, if the optimal base station Beam seen by the terminal is Beam ID31, the terminal searches for SS block type1 with Beam ID31 in fig. 7, completes time-frequency synchronization, and can know that the corresponding base station Beam is Beam ID31 by identifying the sequence of SSs1, and can identify SSs2 at the second 5ms position corresponding to the time-frequency resource to obtain Cell ID, and then can find the corresponding PBCH position according to X symbols and Beam ID 31.

Third embodiment

Referring to fig. 8, an apparatus for initial cell access is shown, where the apparatus 800 includes:

a first transmission module 801 for transmitting PSS in a predetermined cycle using a designated beam;

a second transmitting module 802, configured to transmit the first SSS or the second SSS using the designated beam, where a PSS and the first SSS or the second SSS transmitted using the same beam form an SS block. Optionally, wherein the PSS and the first SSS or the second SSS are multiplexed in FDM or TDM manner.

In this embodiment, optionally, the sequence of the first SSS indicates Beam ID, and the sequence of the second SSS indicates Cell ID; or

In this embodiment, optionally, 2 times the predetermined period is a period, the PSS and the first SSs are transmitted in the SS block in the first half of the period, the PSS and the second SSs2 are transmitted in the SS block in the second half of the period, or the PSS and the second SSs are transmitted in the SS block in the first half of the period, and the PSS and the first SSs are transmitted in the SS block in the second half of the period.

In this embodiment, optionally, the SS block includes a location indication information to help a user identify a center frequency of the system and identify timing information of the symbol where the user is located.

In this embodiment, optionally, the position indication information includes information indicating a position of the SS block in a frequency domain relative to a central frequency point of the system, and/or information indicating a deviation in time relative to a start position of the SS burst set.

In this embodiment, optionally, the apparatus further includes:

In this embodiment, optionally, the specified time-frequency resource and the specified beam are determined according to the following information:

the difference between the starting time of PBCH transmission and the starting time of PSS transmission; or detecting the position of PBCH corresponding to the optimal beam identified by the PSS/SSS.

Fourth embodiment

Referring to fig. 9, an apparatus for initial cell access is shown, the apparatus 900 comprising:

a first receiving module 901, configured to receive a PSS transmitted by a base station at a predetermined period;

a second receiving module 902, configured to receive a first SSS or a second SSS sent by the base station, where a PSS and the first SSS or the second SSS sent using the same beam form an SS block, and the PSS and the first SSS or the second SSS are multiplexed in an FDM or TDM manner.

In this embodiment, optionally, the predetermined period is 2 times as long as one period, the PSS and the first SSs are received in the SS block in the first half of the period, the PSS and the second SSs2 are received in the SS block in the second half of the period, or the PSS and the second SSs are received in the SS block in the first half of the period, and the PSS and the first SSs are received in the SS block in the second half of the period.

In this embodiment, optionally, the apparatus further includes:

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In various embodiments of the present invention, it should be understood that the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

In addition, the terms "system" and "network" are often used interchangeably herein.

It should be understood that the term "and/or" herein is merely one type of association relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In the embodiments provided herein, it should be understood that "B corresponding to a" means that B is associated with a from which B can be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may be determined from a and/or other information.

In the several embodiments provided in the present application, it should be understood that the disclosed method and apparatus may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be physically included alone, or two or more units may be integrated into one unit. The integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

The integrated unit implemented in the form of a software functional unit may be stored in a computer readable storage medium. The software functional unit is stored in a storage medium and includes several instructions to enable a computer device (which may be a personal computer, a server, or a network-side device) to perform some steps of the transceiving method according to various embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

While the preferred embodiments of the present invention have been described, it should be understood that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the principles of the present invention and are within the scope of the present invention.

Claims

1. A method for initial cell access, comprising:

transmitting a primary synchronization signal PSS at a predetermined period;

transmitting a first Secondary Synchronization Signal (SSS) or a second SSS, wherein a PSS and the first SSS or the second SSS transmitted using the same beam form a synchronization signal block (SS block);

and taking 2 times of the preset period as a period, wherein the PSS and the first SSS are transmitted in the SS block in the first half period of the period, the PSS and the second SSS2 are transmitted in the SS block in the second half period of the period, or the PSS and the second SSS are transmitted in the SS block in the first half period of the period, and the PSS and the first SSS are transmitted in the SS block in the second half period of the period.

2. The method of claim 1, wherein PSS and the first SSS or the second SSS are multiplexed in a frequency division multiplexing, FDM, or time division multiplexing, TDM manner.

3. The method of claim 1,

the sequence of the first SSS indicates a beam identification BeamID, and the sequence of the second SSS indicates a Cell identification Cell ID; or

The sequence of the first SSS indicates CellID and the sequence of the second SSS indicates BeamID.

4. The method of claim 1,

the SS block comprises position indication information which is used for helping a user to identify the central frequency point of a system and the timing information of the symbol where the user is located.

5. The method according to claim 4, wherein the position indication information comprises information indicating a position of the SS block relative to a system center frequency point in a frequency domain and/or information indicating an offset relative to a SS burst set start position in time.

6. The method of claim 1, further comprising:

7. The method of claim 6, wherein the designated time-frequency resource and the designated beam are determined according to the following information:

the difference between the starting time of PBCH transmission and the starting time of PSS transmission of the physical broadcast channel; or

8. A method for initial cell access, comprising:

receiving a PSS transmitted by a base station in a preset period;

receiving a first SSS or a second SSS transmitted by the base station, wherein a PSS and the first SSS or the second SSS transmitted by using the same beam form an SS block;

and taking 2 times of the preset period as a period, receiving the PSS and the first SSS in the SS block in the first half period of the period, receiving the PSS and the second SSS2 in the SS block in the second half period of the period, or receiving the PSS and the second SSS in the SS block in the first half period of the period, and receiving the PSS and the first SSS in the SS block in the second half period of the period.

9. The method of claim 8, wherein PSS and the first SSS or the second SSS are multiplexed in FDM or TDM fashion.

10. The method of claim 8,

the sequence of the first SSS indicates a Beam ID, and the sequence of the second SSS indicates a Cell ID; or

11. The method of claim 8,

the SS block also comprises position indication information which is used for helping a user to identify the central frequency point of the system and identify the timing information of the symbol.

12. The method according to claim 11, wherein the position indication information comprises information indicating a position of the SS block in a frequency domain relative to a system center frequency point, and/or information indicating an offset in time relative to an SS burst set start position.

13. The method of claim 8, wherein the PBCH is received in a beam scanning manner at a designated time-frequency resource and a designated beam.

14. The method of claim 13, wherein the designated time-frequency resource and the designated beam are determined according to the following information:

15. An apparatus for initial cell access, comprising:

a first transmission module for transmitting the PSS at a predetermined period;

a second transmitting module, configured to transmit the first SSS or the second SSS, where a PSS and the first SSS or the second SSS transmitted using the same beam form an SS block;

16. The apparatus of claim 15, wherein PSS and first SSS or second SSS are multiplexed in FDM or TDM fashion.

17. The apparatus of claim 15,

18. The apparatus of claim 15,

the SS block comprises position indication information which is used for helping a user to identify the center frequency point of the system and identify the timing information of the symbol.

19. The apparatus according to claim 18, wherein the position indication information includes information indicating a position of the SS block in a frequency domain relative to a center frequency point of the system, and/or information indicating an offset in time relative to an SS burst set start position.

20. The apparatus of claim 15, further comprising:

21. The apparatus of claim 20, wherein the designated time-frequency resource and the designated beam are determined according to the following information:

22. An apparatus for initial cell access, comprising:

a second receiving module, configured to receive a first SSS or a second SSS sent by the base station, where a PSS and the first SSS or the second SSS sent using the same beam form an SS block;

23. The apparatus of claim 22, wherein PSS and first SSS or second SSS are multiplexed in FDM or TDM fashion.

24. The apparatus of claim 22,

25. The apparatus of claim 22,

26. The apparatus according to claim 25, wherein the position indication information includes information indicating a position of the SS block in a frequency domain relative to a center frequency point of the system, and/or information indicating an offset in time relative to a start position of the SS burst set.

27. The apparatus of claim 22, further comprising:

28. The apparatus of claim 27, wherein the designated time-frequency resource and the designated beam are determined according to the following information: