CN106161317B - Synchronization method and device - Google Patents
Synchronization method and device Download PDFInfo
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- CN106161317B CN106161317B CN201510164059.9A CN201510164059A CN106161317B CN 106161317 B CN106161317 B CN 106161317B CN 201510164059 A CN201510164059 A CN 201510164059A CN 106161317 B CN106161317 B CN 106161317B
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Abstract
the invention relates to the technical field of communication, in particular to a synchronization method and a synchronization device, which are used for establishing initial synchronization between UE and a base station on a carrier wave of an unauthorized frequency band. The synchronization method provided by the embodiment of the invention comprises the following steps: the base station configures a first synchronization reference signal; and the base station sends the configured first synchronization reference signal on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the Component Carrier (CC) occupying the unauthorized frequency band, and the first synchronization reference signal is used for carrying out initial synchronization on User Equipment (UE) and the Component Carrier (CC).
Description
Technical Field
The present invention relates to the field of communications technologies, and in particular, to a synchronization method and apparatus.
background
with the rapid increase of data traffic in the mobile internet, it is becoming a development trend to use Long Term Evolution (LTE) technology on an unlicensed frequency band. The unlicensed frequency band is open to all operators, and different operators have the same right to deploy LTE in the unlicensed frequency band. In order to enable a heterogeneous system or a heterogeneous operator to compete fairly for using an unlicensed frequency band, a Listen Before Talk (LBT) mechanism is introduced, that is, before data transmission is performed each time, a period of time is reserved to sense a carrier, a Clear Channel Assessment (CCA) process is performed, data transmission is started when the carrier is sensed to be available, and the maximum duration of data transmission is limited each time.
In order to ensure the reliability of service transmission on the unauthorized frequency band, the authorized frequency band can be adopted to assist the unauthorized frequency band to carry out service transmission, the reliability of the authorized frequency band is combined with the abundant bandwidth resources of the unauthorized frequency band, and the throughput of the system is improved while the reliability of service transmission is ensured. Specifically, in order to ensure the performance of LTE in the unlicensed frequency band, the current protocol requires that an LTE technology is used in the unlicensed frequency band by Carrier Aggregation (CA) or dual connectivity. In the CA mode, a carrier on an authorized frequency band is used as a main carrier, and a carrier on an unauthorized frequency band is used as an auxiliary carrier, so that an unauthorized Access mode (LAA) is implemented with the assistance of an authorized frequency band.
Achieving time-frequency synchronization is necessary for a User Equipment (UE) to correctly demodulate downlink signals. Time-frequency synchronization can be divided into two processes of initial synchronization (coarse synchronization) and synchronization tracking (fine synchronization). In the LTE system, 2 kinds of dedicated reference signals, namely Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS), are designed for the initial Synchronization process. The UE performs initial synchronization with an eNB (evolved Node B, eNB) by capturing a PSS and an SSS transmitted by the eNB, that is, establishes initial time-frequency synchronization. Both PSS and SSS are periodic signals with well-defined time and frequency domain structures. The time domain structure of PSS and SSS is related to the duplex mode of the system; as shown in fig. 1, in a Frequency Division Duplex (FDD) mode, a PSS signal is mapped onto the last Orthogonal Frequency Division Multiplexing (OFDM) symbol of slot 0 and slot 10, and an SSS is mapped onto the previous OFDM symbol of the PSS; as shown in fig. 2, in a Time-Division Duplexing (TDD) mode, a PSS signal is mapped to the third OFDM symbol of slot 2 and slot 12, and an SSS signal is mapped to the last OFDM symbol of slot 1 and slot 11, i.e., SSS is mapped to the 3 rd OFDM symbol position in front of PSS.
In the existing carrier aggregation mode of the authorized frequency band, the auxiliary carriers are all located in the authorized frequency band, and the resources of the auxiliary carriers can be controlled by the base station, so that the base station can ensure that the transmission is carried out in a frame structure format defined by the existing protocol. In LAA-based transmission, for the auxiliary carrier occupying the unlicensed frequency band, because of fair competition by each operator, it is first required to detect whether the carrier in the unlicensed frequency band is idle before access, and if the carrier is idle, the carrier in the unlicensed frequency band may be used, otherwise, the carrier needs to wait until the carrier is idle.
as shown in fig. 3, the CA technology requires that subframes of the primary carrier and the secondary carrier are aligned, that is, the starting time of the radio frame of the secondary carrier needs to be the same as the primary carrier, and the time position where the base station competes for the carrier of the available unlicensed frequency band may not be a subframe boundary, and an incomplete subframe occurs, and the time for transmitting the synchronization signal may not occur in the incomplete subframe. In addition, there is a limitation on the maximum duration of data transmission using the carrier in the unlicensed frequency band, the maximum duration is generally only about 4ms, and the above-mentioned timing for transmitting the synchronization signal, which is specified in the protocol, may not occur within the entire maximum duration.
in summary, the synchronization mechanism for the carrier of the licensed band is not suitable for establishing initial synchronization between the UE and the base station on the carrier of the unlicensed band.
disclosure of Invention
The embodiment of the invention provides a synchronization method and a synchronization device, which are used for establishing initial synchronization between UE and a base station on a carrier wave of an unauthorized frequency band.
The embodiment of the invention provides a synchronization method, which comprises the following steps:
The base station configures a first synchronization reference signal;
and the base station sends the configured first synchronization reference signal on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the Component Carrier (CC) occupying the unauthorized frequency band, and the first synchronization reference signal is used for carrying out initial synchronization on User Equipment (UE) and the Component Carrier (CC).
Optionally, the base station configures a first synchronization reference signal, including:
And the base station configures a sequence scrambled by a cell Identification (ID) for the first synchronous reference signal.
Optionally, the cell ID is a physical layer cell ID corresponding to a component carrier CC of the unlicensed frequency band; or, the cell ID is a physical layer cell ID corresponding to a component carrier CC of an authorized frequency band occupied by the base station.
Optionally, before the base station configures the first synchronization reference signal, the method further includes:
and the base station indicates the cell identification ID of the sequence for scrambling the first synchronization reference signal to User Equipment (UE) on a member carrier (CC) of the occupied authorized frequency band.
Optionally, the configuring, by the base station, a sequence scrambled by using a cell identity ID for the first synchronization reference signal includes:
The base station configures a sequence of the first synchronization reference signal based on a sequence design form of an auxiliary synchronization signal SSS transmitted on an authorized frequency band and a preset cell ID for scrambling; or, the base station generates a sequence of a first synchronization reference signal based on a preset cell ID for scrambling, where a bandwidth occupied by the first synchronization reference signal is greater than a bandwidth occupied by a secondary synchronization signal SSS transmitted on an authorized frequency band.
Optionally, the base station configures a first synchronization reference signal, including:
The base station configures a first synchronization reference signal carrying indication information.
optionally, the indication information is used for indicating control information transmitted after the first synchronization reference signal.
Optionally, the method further comprises:
And if the first synchronous reference signal does not occupy the total bandwidth of the component carrier CC of the unauthorized frequency band, the base station sends other reference signals on other frequency domain resources except the frequency domain resource occupied by the first synchronous reference signal in the first complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unauthorized frequency band.
optionally, the method further comprises:
The base station configures a second synchronization reference signal;
And the base station sends the second synchronous reference signal on a second complete orthogonal frequency division multiplexing OFDM symbol from the starting time, so that the adjacent cell identifies that the component carrier CC of the unauthorized frequency band is occupied by the base station.
optionally, the base station configures a second synchronization reference signal, including:
The base station configures a sequence of the second synchronization reference signal based on a sequence design form of a Primary Synchronization Signal (PSS) transmitted on an authorized frequency band; or, generating a sequence of a second synchronization reference signal, where a bandwidth occupied by the second synchronization reference signal is greater than a bandwidth occupied by a primary synchronization signal PSS transmitted on the licensed frequency band.
Optionally, the sequence of the second synchronization reference signal carries indication information.
optionally, the indication information is used to indicate control information transmitted after the second synchronization reference signal.
optionally, the first synchronization reference signal and the second synchronization reference signal carry information of a physical layer cell ID corresponding to the component carrier CC of the unlicensed frequency band, and the first synchronization reference signal and the second synchronization reference signal are used for cell search of neighboring cell user equipment UE.
optionally, after the base station transmits the second synchronization reference signal, the method further includes:
And if the second synchronous reference signal does not occupy the total bandwidth of the component carrier CC of the unauthorized frequency band, the base station sends other reference signals on other frequency domain resources except the frequency domain resource occupied by the second synchronous reference signal in the second complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unauthorized frequency band.
another embodiment of the present invention provides a synchronization method, including:
User Equipment (UE) captures a first synchronous reference signal sent by a base station on a Component Carrier (CC) of an unauthorized frequency band; the first synchronization reference signal is sent by the base station on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of a CC occupying the unlicensed frequency band;
And the UE performs initial synchronization with the CC of the unlicensed frequency band based on the acquired first synchronization reference signal.
an embodiment of the present invention provides a synchronization apparatus, including:
A configuration module for configuring a first synchronization reference signal;
A sending module, configured to send the configured first synchronization reference signal on a first complete orthogonal frequency division multiplexing OFDM symbol from a starting time of a component carrier CC of an unlicensed frequency band occupied by a base station, for initial synchronization between user equipment UE and the component carrier CC.
Another embodiment of the present invention provides a synchronization apparatus, including:
the device comprises an acquisition module, a synchronization module and a synchronization module, wherein the acquisition module is used for acquiring a first synchronization reference signal sent by a base station on a Component Carrier (CC) of an unauthorized frequency band; the first synchronization reference signal is sent by the base station on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of a CC occupying the unlicensed frequency band;
a synchronization module, configured to perform initial synchronization with the CC in the unlicensed frequency band based on the first synchronization reference signal captured by the capture module.
In the embodiment of the invention, after the base station configures the first synchronous reference signal, the configured first synchronous reference signal is sent on the first complete orthogonal frequency division multiplexing OFDM symbol from the initial time of the member carrier CC occupying the unauthorized frequency band, thereby realizing the establishment of the initial synchronization of the UE and the base station on the carrier of the unauthorized frequency band.
Drawings
Fig. 1 is a schematic time domain structure diagram of a synchronization signal in FDD mode;
FIG. 2 is a schematic diagram of a time domain structure of a synchronization signal in TDD mode;
fig. 3 is a schematic diagram of subframe alignment of primary and secondary carriers in CA;
FIG. 4 is a flowchart of a synchronization method according to an embodiment of the present invention;
Fig. 5 is a schematic diagram of data transmission on a CC in an unlicensed frequency band with the aid of a CC in a licensed frequency band;
FIG. 6 is a flowchart of a synchronization method according to a second embodiment of the present invention;
Fig. 7 is a flowchart of a synchronization method according to a third embodiment of the present invention;
FIG. 8 is a flowchart of a synchronization method according to a fourth embodiment of the present invention;
Fig. 9 is a diagram illustrating data transmission on CCs in an unlicensed frequency band;
Fig. 10 is a schematic structural diagram of a synchronization apparatus according to a fifth embodiment of the present invention;
Fig. 11 is a schematic structural diagram of a synchronization apparatus according to a sixth embodiment of the present invention.
Detailed Description
in the embodiment of the invention, after the base station configures the first synchronous reference signal, the configured first synchronous reference signal is sent on the first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the Component Carrier (CC) occupying the unauthorized frequency band, so that the UE and the base station can establish initial synchronization on the Carrier of the unauthorized frequency band.
The embodiments of the present invention will be described in further detail with reference to the drawings attached hereto.
Example one
as shown in fig. 4, a flowchart of a synchronization method provided in an embodiment of the present invention includes the following steps:
S401: the base station configures a first synchronization reference signal.
s402: the base station sends the configured first synchronization reference signal on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of a Component Carrier (CC) occupying an unauthorized frequency band, and the first synchronization reference signal is used for initial synchronization of User Equipment (UE) and the CC.
In specific implementation, after a base station successfully occupies a certain component carrier CC of an unlicensed frequency band, if the occupied start time is the boundary position of a complete OFDM symbol, a first synchronization reference signal may be immediately sent, and if the occupied start time is not the boundary position of the OFDM symbol, a placeholder (Preamble) for occupying the CC may be first sent, and after the boundary position of the complete OFDM symbol is reached, the first synchronization reference signal is sent. After acquiring the first synchronization reference signal, the UE establishes initial synchronization, i.e. time-frequency coarse synchronization, with the base station.
Optionally, the method further comprises:
and if the first synchronous reference signal does not occupy the total bandwidth of the component carrier CC of the unauthorized frequency band, the base station sends other reference signals on other frequency domain resources except the frequency domain resource occupied by the first synchronous reference signal in the first complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unauthorized frequency band.
in a Specific implementation process, if the first synchronization Reference Signal does not occupy the total bandwidth of the component carrier CC in the unlicensed frequency band occupied by the base station, other Reference Signals may be sent on the frequency domain resources remaining in the first complete OFDM symbol, for example, one or more of Cell-Specific Reference Signals (CRS), channel state information Reference Signals (CSI-RS), and Positioning Reference Signals (PRS) are sent, and the UE performs synchronization tracking on the Reference Signals to achieve time-frequency fine synchronization.
optionally, in S401, the base station configures a first synchronization reference signal, including:
The base station configures a sequence scrambled by a Cell Identity (Cell ID) for the first synchronization reference signal.
In an implementation, in order to enable the UE to quickly acquire the first synchronization reference signal, the first synchronization reference credit may be bound to a Cell ID, and the UE quickly acquires the first synchronization reference signal by matching a specific Cell ID.
Alternatively, the UE may obtain the Cell ID for scrambling the first synchronization reference signal by:
before the base station configures the first synchronization reference signal, indicating a Cell ID of a sequence for scrambling the first synchronization reference signal to UE on a component carrier CC of an occupied authorized frequency band.
in a specific implementation process, the base station may indicate, to the UE, some prior information of a component carrier CC of an unlicensed frequency band to be occupied at a component carrier CC of an occupied licensed frequency band, for example, a Cell ID (in a current 3GPP standard, each CC has an independent Cell ID), a center frequency and a bandwidth of the CC, a sequence of the CC, or a candidate sequence set of the CC (the CC finally adopts one sequence in the candidate sequence set) corresponding to the component carrier CC of the unlicensed frequency band; the UE may also obtain a cell ID corresponding to a CC of the base station on the licensed frequency band. The only thing the UE does not know is the actual timing of Downlink (DL) data transmission, and therefore signal acquisition is required. In practical implementation, the base station may explicitly indicate the cell ID to the UE through signaling on the member carrier CC of the occupied authorized frequency band, or implicitly indicate the cell ID to the UE, for example, a relationship between the cell ID used for scrambling the first synchronization reference signal and a cell ID corresponding to the member CC of the authorized frequency band is agreed in advance by the UE, and the UE determines the cell ID used for scrambling the first synchronization reference signal based on the cell ID corresponding to the member CC of the authorized frequency band.
optionally, the cell ID is a physical layer cell ID corresponding to a component carrier CC of the unlicensed frequency band; or, the cell ID is a physical layer cell ID corresponding to a component carrier CC of an authorized frequency band occupied by the base station.
in a specific implementation process, the Cell ID scrambled on the first synchronization reference signal may be a Cell ID corresponding to a CC of an unlicensed frequency band carrying the first synchronization reference signal, or a Cell ID corresponding to a carrier of a licensed frequency band occupied by the base station. In the former way, the UE needs to generate a local replication sequence for each CC (scramble the sequence with the cell ID corresponding to the CC); for the latter mode, the UE only needs to generate one local replication sequence (cell ID scrambling corresponding to the main carrier of the occupied authorized frequency band is used), so that the processing complexity of the UE can be reduced. In addition, the time of all CCs occupied by the base station on the unlicensed frequency band is completely synchronous, when the first synchronous reference signal is scrambled by using the Cell ID corresponding to the main carrier on the licensed frequency band, when the monitored CC needs to be replaced by the UE, the local timing and the baseband capturing process do not need to be adjusted, and only the down-conversion frequency needs to be modified at the radio frequency, so that other CCs which are replaced and monitored fall into the baseband capturing process. Therefore, the latter method provides a larger optimization space for the time-frequency acquisition algorithm of the UE, and is a preferred method.
Optionally, in S401, the base station may design a sequence of the first synchronization reference signal based on a sequence of the SSS sent on the CC of the licensed frequency band, or may additionally design a new sequence, so that the new sequence occupies a larger bandwidth in the frequency domain; that is, the base station configures a sequence scrambled by using a cell identity ID for the first synchronization reference signal, including:
the base station configures a sequence of the first synchronization reference signal based on a sequence design form of an auxiliary synchronization signal SSS transmitted on an authorized frequency band and a preset cell ID for scrambling; or, the base station generates a sequence of a first synchronization reference signal based on a preset cell ID for scrambling, where a bandwidth occupied by the first synchronization reference signal is greater than a bandwidth occupied by a secondary synchronization signal SSS transmitted on an authorized frequency band.
Here, in order to better explain the idea of designing the sequence of the first synchronization reference signal according to the embodiment of the present invention, the following description is made for the conventional synchronization signal:
the PSS and SSS sent on the CC in the licensed band carry both cell discovery and time-frequency coarse synchronization functions. The UE needs to obtain cell ID information by blind detection of PSS and SSS signals. The value range of the cell ID is 0-503. In order to facilitate the UE to identify the cell ID, the cell ID is decomposed into two parts, namely a physical layer cell ID group number and an ID number in each physical layer cell ID group, wherein the value range is 0-167, and the value range is 0-2.
PSS has 3 candidate sequences, which value is taken to be relevant. The UE firstly needs to capture the PSS, and blindly detects that the UE de-matches the SSS after time-frequency coarse synchronization is established with the base station through the PSS through matching operation. Under the premise of known a priori, the SSS has 168 candidate sequences, so the UE needs to perform 168 correlation matching operations to blindly detect the signal, but since time-frequency coarse synchronization is already established when the SSS is blindly detected, the complexity of blindly detecting the SSS is much lower than that of blindly detecting the PSS. It can be seen that the UE matching synchronization signal includes time domain matching and sequence matching, where the processing complexity of the time domain matching is greater than that of the sequence matching.
When acquiring the PSS of the conventional licensed frequency band, the UE needs to perform blind detection from 3 candidate sequences. However, in the embodiment of the present invention, since the first synchronization reference signal is scrambled by using the cell ID known to the UE, and the UE only matches one known sequence, the processing complexity of performing synchronization acquisition in the embodiment of the present invention is 1/3 of the processing complexity of the conventional acquisition PSS.
In fact, to simplify synchronization signal acquisition, in a WIreless Fidelity (WIFI) system, the synchronization signals on all CCs use the same sequence, i.e., without cell ID scrambling. In this way, after capturing the synchronization signal, the UE needs to demodulate data after the synchronization signal, and can determine whether the data is addressed to the UE based on the data obtained by demodulation. If the LAA also uses the same synchronization signal design manner as the WIFI, that is, the first synchronization reference signal is not scrambled by the cell ID, after capturing the first synchronization reference signal, the UE needs to try to blindly detect Downlink Control Information (DCI) after the first synchronization reference signal, and can determine whether Downlink data sent by the base station is addressed to the UE based on the DCI. For the UE, blind detection of DCI is a relatively complex data processing operation, which causes a large processing overhead. Therefore, with the assistance of the primary carrier of the licensed frequency band, the embodiment of the present invention may scramble the first synchronization reference signal sent on the CC of the unlicensed frequency band using the Cell ID indicated to the UE by the primary carrier. In this way, the UE can acquire only the synchronization signal scrambled by the known Cell ID, simplifying the processing complexity of acquiring the synchronization signal. By adopting the scrambling mode, the complexity of the UE for detecting the synchronous signal is reduced, and meanwhile, the UE can be ensured not to be connected to other base stations by mistake.
In a specific implementation, the synchronization signal can also be used as an information carrier, and specifically, in S101, the base station can configure a first synchronization reference signal carrying indication information; the indication information may be used to indicate control information transmitted after the first synchronization reference signal.
In a specific implementation, the first synchronization reference signal carries the indication information in a manner of indicating different information through different sequences, specifically, the base station may configure a candidate sequence set for the first synchronization reference signal, and the base station specifically selects which candidate sequence to send as the sequence of the first synchronization reference signal, depending on the indication information carried in addition. Of course, these candidate sequences are all scrambled by a cell ID known to the UE. Accordingly, the UE locally generates several repeated candidate sequences, i.e. a candidate sequence set configured by the base station, on the premise of knowing the cell ID, correlates the candidate sequences with the received signal, and blindly detects a unique correct candidate sequence from the candidate sequences, wherein the number of the blindly detected correct candidate sequence corresponds to specific indication information.
For example, if the base station configures the sequence of the first synchronization reference signal based on the sequence design form of the SSS transmitted on the CC of the licensed frequency band and the preset cell ID for scrambling, the sequence of the first synchronization signal may be:
Wherein n is a sequence number, a cell ID, I is information carried on a first synchronization reference signal, SSS () is a sequence design form of SSS transmitted on a CC of an authorized frequency band, and c () is a certain scrambling function. For example, c () may be some cyclic shift of an m-sequence, where X is a positive integer, such as X ═ 62; 0 ≦ i ≦ X-1, where X (i) may be generated by a shift register whose polynomial expression is: x (n +31) (x (n +3) + x (n)) mod2, and the initial value of the shift register x1(0) ═ 1, x1(n) ═ 0, and n ═ 1, 2.
in a specific implementation, the indication information carried by the first synchronization reference signal may include one or more of the following information: information indicating a subsequent presence or absence of a second synchronization reference signal; information for indicating a subsequent presence or absence of LAA control signaling (the second synchronization reference signal belongs to one of the LAA control signaling); and if the LAA control signaling exists subsequently, indicating the information of the symbol length occupied by the LAA control signaling, and the like.
in a specific implementation process, the base station may determine whether the first synchronization reference signal includes the LAA control signaling based on the opportunity of contending for the CC in the unlicensed frequency band. If the time of the CC contending for the unlicensed frequency band is very close to the next subframe boundary (for example, X is 4 OFDM symbols away from the next subframe boundary), after the OFDM symbol where the first synchronization reference signal is located is removed, only 4-1-3 complete OFDM symbols are left away from the next subframe boundary, which is not enough to support effective downlink data transmission. These 3 complete OFDM symbols can now be used for transmitting LAA control signaling. On the other hand, if the time of the contention for the CC in the unlicensed frequency band is far from the next subframe boundary (for example, the time is 10 OFDM symbols away from the next subframe boundary X), 10-1 to 9 OFDM symbols are left after the OFDM symbol where the first synchronization reference signal is located is removed, these resources may support effective downlink data transmission, and at this time, the downlink data may be directly transmitted without transmitting the LAA control signaling.
In addition to the first synchronization reference signal, the embodiment of the present invention may also send a second synchronization reference signal on the CC in the occupied unlicensed frequency band, so as to improve the sensitivity of the neighboring base station to find that the CC is occupied.
specifically, the method further comprises:
the base station configures a second synchronization reference signal;
and the base station sends the second synchronous reference signal on a second complete orthogonal frequency division multiplexing OFDM symbol from the starting time, so that the adjacent cell identifies that the component carrier CC of the unauthorized frequency band is occupied by the base station.
Optionally, after the base station transmits the second synchronization reference signal, the method further includes:
And if the second synchronous reference signal does not occupy the total bandwidth of the component carrier CC of the unauthorized frequency band, the base station sends other reference signals on other frequency domain resources except the frequency domain resource occupied by the second synchronous reference signal in the second complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unauthorized frequency band.
In a Specific implementation process, if the second synchronization Reference Signal does not occupy the total bandwidth of the component carrier CC in the unlicensed frequency band occupied by the base station, other Reference Signals may be sent on the remaining frequency domain resources in the second complete OFDM symbol, for example, one or more of a Cell-Specific Reference Signal (CRS), a channel state information Reference Signal (CSI-RS), and a Positioning Reference Signal (PRS) are sent, and the UE performs synchronization tracking on the Reference Signals to achieve time-frequency fine synchronization.
Optionally, in the above step, the base station may design the sequence of the second synchronization reference signal based on the sequence of the PSS sent on the CC of the licensed frequency band, or may additionally design a new sequence, so that the new sequence occupies a larger bandwidth in the frequency domain; that is, the base station configures a second synchronization reference signal including:
The base station configures a sequence of the second synchronization reference signal based on a sequence design form of a Primary Synchronization Signal (PSS) transmitted on an authorized frequency band; or, generating a sequence of a second synchronization reference signal, where a bandwidth occupied by the second synchronization reference signal is greater than a bandwidth occupied by a primary synchronization signal PSS transmitted on the licensed frequency band.
optionally, the sequence of the second synchronization reference signal carries indication information, and the indication information may be used to indicate control information transmitted after the second synchronization reference signal.
In specific implementation, the sequence of the second synchronization reference signal may not be bound to the cell ID, multiple candidate sequences may be designed for the second synchronization reference signal to carry different indication information, and when the second synchronization reference signal is configured, a corresponding sequence is selected from the candidate sequences based on the indication information that needs to be carried; the indication information may include information indicating the symbol length of the subsequently transmitted LAA control signaling, or include other parameters defined in the standardization, or may be reserved for later use, or reserved for vendor use, etc. For example, when the second synchronization reference signal is designed based on the sequence design form of the PSS transmitted on the licensed band, the second synchronization reference signal may or may not be bound to the ID number within the group. When the second synchronization reference signal is not bound to the first synchronization reference signal, some additional indication information can be carried through the selection of the candidate sequence of the second synchronization reference signal; here, since there are 3 candidate sequences of the second synchronization reference signal referring to the PSS in total, a maximum of 3 pieces of indication information can be carried.
The function and design of the second synchronization reference signal according to the embodiment of the present invention are further described as follows:
The second synchronization reference signal in the embodiment of the present invention is mainly used to improve the sensitivity of the base station and the UE of the neighboring cell to find that the CC is occupied, so as to avoid interference, and the technical idea is as follows:
when a component carrier CC in an unlicensed frequency band needs to be occupied, a current busy-idle state of the CC to be occupied needs to be sensed through a Channel blind idle state sensing technology, that is, a Clear Channel Assessment (CCA) process is performed. There are currently two CCA detection techniques, including energy detection and signal detection; signal detection has a higher perceptual sensitivity than energy detection. For signal detection, the detecting end needs to know the format of the signal sent by the signal sending end, then locally reproduces the same signal, and judges whether the concerned sending signal exists and whether the receiving power of the signal exceeds a preset receiving power threshold through coherent reception.
in the embodiment of the invention, in order to enable the UE to quickly acquire the first synchronization reference signal, the first synchronization reference signal is scrambled by adopting the cell ID. This is because the range of the cell ID is 0-503, and if the UE does not obtain the prior information of the cell ID, it will be very difficult to acquire the first synchronization reference signal. Also because of the cell ID scrambling, the first synchronization reference signal does not support CCA detection at the signal level by the base station and the UE of the neighbor cell. Therefore, the second synchronization reference signal is designed in the embodiment of the present invention to support the base station and the UE of the neighboring cell to perform CCA detection at the signal level on the CC that transmits the first synchronization reference signal.
Further, in order to facilitate the base stations and UEs of the neighboring cells to acquire the second synchronization reference signal, the second synchronization reference signal should contain all the information for facilitating the acquisition, for example, the sequence of the second synchronization reference signal may be a fixed sequence independent of the cell ID or a sequence selected from a candidate sequence set containing a smaller number of sequences. When the sequence of the second synchronization reference signal is a sequence selected from a candidate sequence set including a smaller number of sequences, some additional indication information may be carried by the second synchronization reference signal, i.e. different sequences in the candidate sequence set carry different indication information.
as already explained in the above description, the first synchronization reference signal may be designed based on SSS, the second synchronization reference signal may be designed based on PSS, and when the first and second synchronization reference signals carry cell ID information, the UE of the neighboring cell may perform cell search based on the two synchronization signals. The concrete description is as follows:
in fact, it is not necessary to perform cell search in the unlicensed band. When the base station operates in a Carrier Aggregation (CA) or Dual Connectivity (DC) mode, the UE may access to CCs of the unlicensed frequency band with the aid of component carriers CCs of the licensed frequency band. The premise that the UE performs downlink communication on the CC in the unlicensed frequency band is that the UE has already established connection with the base station on the CC in the licensed frequency band, so that the UE can listen to a downlink data packet sent to itself on the CC in a certain unlicensed frequency band under the indication of the information transmitted on the received CC in the licensed frequency band, as shown in fig. 5.
The cell search performed by the UE in the neighboring cell based on the first synchronization reference signal and the second synchronization reference signal carrying the cell ID may be:
After confirming that the second synchronization reference signal is acquired, the UE in the adjacent cell extracts the cached first synchronization reference signal from the buffer;
and the adjacent cell UE determines cell identification IDs corresponding to the first synchronous reference signal and the second synchronous reference signal based on information carried in the first synchronous reference signal and the second synchronous reference signal.
in a specific implementation process, the UE of the neighboring cell may buffer data carried by two OFDM symbols each time, and after it is confirmed that the second synchronization reference signal bound to the UE is captured, extract an OFDM symbol adjacent to the OFDM symbol carrying the second synchronization reference signal from the buffer, and recover the first synchronization reference signal scrambled by using the cell ID from the OFDM symbol; based on the information carried in the first synchronization reference signal and the second synchronization reference signal, the cell IDs carried by the first synchronization reference signal and the second synchronization reference signal can be determined.
Example two
The following is a synchronization method based on the UE side, and details of the specific implementation are not repeated in the above embodiment.
As shown in fig. 6, a flowchart of a synchronization method provided in the second embodiment of the present invention includes:
S601: the method comprises the steps that UE captures a first synchronous reference signal sent by a base station on a Component Carrier (CC) of an unauthorized frequency band; the first synchronization reference signal is transmitted by the base station on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from a starting time of a CC occupying the unlicensed frequency band.
S602: and the UE performs initial synchronization with the CC of the unlicensed frequency band based on the acquired first synchronization reference signal.
optionally, the acquiring, by the UE, the first synchronization reference signal sent by the base station on the CC in the unlicensed frequency band includes:
The UE receives a cell identification ID of a sequence used for scrambling a first synchronous reference signal on a Component Carrier (CC) of an authorized frequency band;
And the UE captures the first synchronous reference signal sent by the base station on the CC of the unauthorized frequency band based on the cell ID.
optionally, the cell ID is a physical layer cell ID corresponding to a component carrier CC of the unlicensed frequency band; or the cell ID is a physical layer cell ID corresponding to the component carrier CC of the authorized frequency band.
Optionally, the method further comprises:
And the UE receives other reference signals on the OFDM symbol for transmitting the first synchronous reference signal, and synchronously tracks the Component Carrier (CC) of the unauthorized frequency band based on the received other reference signals.
optionally, the method further comprises:
the UE captures a second synchronous reference signal sent by the base station on a Component Carrier (CC) of an unauthorized frequency band; the second synchronization reference signal is sent by the base station on a second complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the CC occupying the unlicensed frequency band;
And the UE performs initial synchronization with the CC of the unlicensed frequency band based on the acquired second synchronization reference signal.
Optionally, the method further comprises:
and the UE receives other reference signals on the OFDM symbol for transmitting the second synchronous reference signal, and synchronously tracks the component carrier CC of the unlicensed frequency band based on the received other reference signals.
The idea of an embodiment of the invention is further illustrated by two specific embodiments.
EXAMPLE III
as shown in fig. 7, a flowchart of a synchronization method provided in the third embodiment of the present invention includes:
S701: the base station configures a first synchronization reference signal scrambled with a cell ID.
s702: and the base station sends the configured first synchronous reference signal on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the member carrier (CC) occupying the unlicensed frequency band.
S703: the UE captures a first synchronization reference signal sent by a base station on a CC of an unlicensed frequency band based on a cell ID of a sequence for scrambling the first synchronization reference signal received on the CC of the licensed frequency band.
s704: and the UE establishes initial synchronization with the CC of the unlicensed frequency band based on the acquired first synchronous reference signal.
Example four
As shown in fig. 8, a flowchart of a synchronization method provided in the fourth embodiment of the present invention includes:
s801: a base station configures a first synchronous reference signal which is scrambled by a cell ID and carries first indication information, wherein the first indication information is used for indicating a second synchronous reference signal which has transmission subsequently; and configuring a second synchronization reference signal carrying second indication information, wherein the second indication information is used for indicating the symbol length of the subsequently transmitted LAA control signaling.
here, the first synchronization reference signal may have a plurality of candidate sequences scrambled with cell IDs, and the base station selects a candidate sequence corresponding to first indication information to be carried by the first synchronization reference signal as a sequence of the first synchronization reference signal to be transmitted, based on the first indication information. The second synchronization reference signal may not be bound to the cell ID, and it may have a plurality of candidate sequences respectively corresponding to different second indication information, and the base station selects, based on the second indication information that needs to be carried by the second synchronization reference signal, the candidate sequence corresponding to the second indication information as the sequence of the second synchronization reference signal that needs to be sent.
S802: and the base station sends the configured first synchronous reference signal on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the member carrier (CC) occupying the unlicensed frequency band, and sends the configured second synchronous reference signal on a second complete OFDM symbol.
s803: and the UE in the service cell where the base station is located captures the first synchronous reference signal sent by the base station on the CC of the unauthorized frequency band based on the cell ID of the sequence which is received on the CC of the authorized frequency band and used for scrambling the first synchronous reference signal.
s804: and the UE receives a second synchronous reference signal based on the captured first indication information carried in the first synchronous reference signal, and establishes initial synchronization with the CC of the unauthorized frequency band based on the first synchronous reference signal and the second synchronous reference signal.
S805: and after detecting the second synchronous reference signal, the base station of the adjacent cell determines that the CC of the unauthorized frequency band is occupied and does not compete for the CC any more.
As shown in fig. 9, the base station transmits a placeholder (Preamble) with a length smaller than 1 OFDM symbol from a time t0 when sensing that a certain component carrier CC located in an unlicensed frequency band is in an idle state until a next OFDM symbol boundary, and transmits a first synchronization reference signal in a first complete OFDM symbol and a second synchronization reference signal in a second complete OFDM symbol. Therefore, the actual transmission time of the first synchronization reference signal and the second synchronization reference signal in the embodiment of the present invention depends on the actual channel contention status, and is aperiodic. In this embodiment of the present invention, after the first synchronization reference signal, an LAA Control signaling including the second synchronization reference signal may be transmitted, and after the LAA Control signaling, Downlink data may be transmitted, where the Downlink data includes an enhanced Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH), or includes only a PDSCH.
The frequency domain structures of the first synchronous reference signal and the second synchronous reference signal in the embodiment of the invention can use the existing PSS/SSS signal design for reference, namely only occupying 6 Resource Blocks (RB) on the central frequency, namely 1.08MHz bandwidth. Alternatively, a new reference signal is additionally designed or extended based on the existing synchronization signal to occupy a larger bandwidth in the frequency domain. If the first synchronization reference signal and/or the second synchronization reference signal do not occupy the frequency domain bandwidth of the entire CC, other reference signals such as CRS, CSI-RS, PRS, etc. may be transmitted on other frequency resources, and the UE may establish time-frequency fine synchronization with the base station by tracking these reference signals.
based on the same inventive concept, the embodiment of the present invention further provides a synchronization apparatus corresponding to the synchronization method, and as the principle of the apparatus for solving the problem is similar to the synchronization method of the embodiment of the present invention, the implementation of the apparatus may refer to the implementation of the method, and repeated details are not repeated.
EXAMPLE five
as shown in fig. 10, a schematic structural diagram of a synchronization apparatus provided in a fifth embodiment of the present invention includes:
A configuration module 101, configured to configure a first synchronization reference signal;
A sending module 102, configured to send the configured first synchronization reference signal on a first complete orthogonal frequency division multiplexing OFDM symbol from a starting time of a component carrier CC of an unlicensed frequency band occupied by a base station, so that a user equipment UE performs initial synchronization with the component carrier CC.
optionally, the configuration module 101 is specifically configured to:
And configuring a sequence scrambled by a cell Identification (ID) for the first synchronization reference signal.
optionally, the cell ID is a physical layer cell ID corresponding to a component carrier CC of the unlicensed frequency band; or, the cell ID is a physical layer cell ID corresponding to a component carrier CC of an authorized frequency band occupied by the base station.
Optionally, the sending module 102 is further configured to: and indicating the cell identification ID of the sequence used for scrambling the first synchronization reference signal to User Equipment (UE) on a Component Carrier (CC) of an authorized frequency band occupied by the base station.
Optionally, the configuration module 101 is specifically configured to:
configuring a sequence of the first synchronization reference signal based on a sequence design form of a secondary synchronization signal SSS transmitted on an authorized frequency band and a preset cell ID for scrambling; or, based on a preset cell ID for scrambling, generating a sequence of a first synchronization reference signal, where a bandwidth occupied by the first synchronization reference signal is greater than a bandwidth occupied by a secondary synchronization signal SSS transmitted on an authorized frequency band.
Optionally, the configuration module 101 is specifically configured to:
And configuring a first synchronization reference signal carrying indication information.
Optionally, the indication information is used for indicating control information transmitted after the first synchronization reference signal.
Optionally, the sending module 102 is further configured to:
And if the first synchronous reference signal does not occupy the total bandwidth of the component carrier CC of the unauthorized frequency band, sending other reference signals on other frequency domain resources except the frequency domain resource occupied by the first synchronous reference signal in the first complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unauthorized frequency band.
Optionally, the configuration module 101 is further configured to: configuring a second synchronization reference signal;
the sending module 102 is further configured to: and sending the second synchronization reference signal on a second complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time, wherein the second synchronization reference signal is used for identifying that the Component Carrier (CC) of the unlicensed frequency band is occupied by the base station by an adjacent cell.
optionally, the configuration module 101 is specifically configured to:
Configuring a sequence of the second synchronization reference signal based on a sequence design form of a Primary Synchronization Signal (PSS) transmitted on an authorized frequency band; or, generating a sequence of a second synchronization reference signal, where a bandwidth occupied by the second synchronization reference signal is greater than a bandwidth occupied by a primary synchronization signal PSS transmitted on the licensed frequency band.
Optionally, the sequence of the second synchronization reference signal carries indication information.
optionally, the indication information is used to indicate control information transmitted after the second synchronization reference signal.
Optionally, the first synchronization reference signal and the second synchronization reference signal carry information of a physical layer cell ID corresponding to the component carrier CC of the unlicensed frequency band, and the first synchronization reference signal and the second synchronization reference signal are used for cell search of neighboring cell user equipment UE.
optionally, the sending module 102 is further configured to:
And if the second synchronization reference signal does not occupy the total bandwidth of the component carrier CC of the unlicensed frequency band, sending other reference signals on other frequency domain resources except the frequency domain resource occupied by the second synchronization reference signal in the second complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unlicensed frequency band.
EXAMPLE six
as shown in fig. 11, a schematic structural diagram of a synchronization apparatus provided in a sixth embodiment of the present invention includes:
An acquiring module 111, configured to acquire a first synchronization reference signal sent by a base station on a component carrier CC in an unlicensed frequency band; the first synchronization reference signal is sent by the base station on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of a CC occupying the unlicensed frequency band;
A synchronization module 112, configured to perform initial synchronization with the CC of the unlicensed frequency band based on the first synchronization reference signal acquired by the acquisition module 111.
Optionally, the synchronization module 112 is further configured to:
and receiving other reference signals on the OFDM symbol for transmitting the first synchronous reference signal, and synchronously tracking the component carrier CC of the unlicensed frequency band based on the received other reference signals.
Optionally, the capturing module 111 is further configured to: capturing a second synchronous reference signal sent by the base station on a Component Carrier (CC) of an unauthorized frequency band; the second synchronization reference signal is sent by the base station on a second complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the CC occupying the unlicensed frequency band;
the synchronization module 112 is further configured to perform initial synchronization with the CC of the unlicensed frequency band based on the second synchronization reference signal acquired by the acquisition module 111.
optionally, the synchronization module 112 is further configured to:
and receiving other reference signals on the OFDM symbol for transmitting the second synchronous reference signal, and synchronously tracking the component carrier CC of the unlicensed frequency band based on the received other reference signals.
as will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
these computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
while preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (30)
1. a method of synchronization, the method comprising:
the base station configures a first synchronization reference signal;
The base station sends the configured first synchronization reference signal on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of a Component Carrier (CC) occupying an unauthorized frequency band, and the first synchronization reference signal is used for carrying out initial synchronization on User Equipment (UE) and the Component Carrier (CC);
Wherein the base station configures a first synchronization reference signal, comprising: the base station configures a first synchronization reference signal carrying indication information.
2. The method of claim 1, wherein the base station configuring the first synchronization reference signal comprises:
and the base station configures a sequence scrambled by a cell Identification (ID) for the first synchronous reference signal.
3. The method of claim 2, wherein the cell ID is a physical layer cell ID corresponding to a component carrier CC of the unlicensed frequency band; or, the cell ID is a physical layer cell ID corresponding to a component carrier CC of an authorized frequency band occupied by the base station.
4. the method of claim 2, wherein prior to the base station configuring the first synchronization reference signal, further comprising:
And the base station indicates the cell identification ID of the sequence for scrambling the first synchronization reference signal to User Equipment (UE) on a member carrier (CC) of the occupied authorized frequency band.
5. The method of claim 2, wherein the base station configures a sequence scrambled with a cell Identity (ID) for the first synchronization reference signal, comprising:
The base station configures a sequence of the first synchronization reference signal based on a sequence design form of an auxiliary synchronization signal SSS transmitted on an authorized frequency band and a preset cell ID for scrambling; or, the base station generates a sequence of a first synchronization reference signal based on a preset cell ID for scrambling, where a bandwidth occupied by the first synchronization reference signal is greater than a bandwidth occupied by a secondary synchronization signal SSS transmitted on an authorized frequency band.
6. The method of any one of claims 1-5, wherein the indication information is used to indicate control information transmitted after the first synchronization reference signal.
7. the method of claim 1, wherein the method further comprises:
And if the first synchronous reference signal does not occupy the total bandwidth of the component carrier CC of the unauthorized frequency band, the base station sends other reference signals on other frequency domain resources except the frequency domain resource occupied by the first synchronous reference signal in the first complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unauthorized frequency band.
8. the method of claim 1, wherein the method further comprises:
The base station configures a second synchronization reference signal;
And the base station sends the second synchronous reference signal on a second complete orthogonal frequency division multiplexing OFDM symbol from the starting time, so that the adjacent cell identifies that the component carrier CC of the unauthorized frequency band is occupied by the base station.
9. The method of claim 8, wherein the base station configures a second synchronization reference signal comprising:
the base station configures a sequence of the second synchronization reference signal based on a sequence design form of a Primary Synchronization Signal (PSS) transmitted on an authorized frequency band; or, generating a sequence of a second synchronization reference signal, where a bandwidth occupied by the second synchronization reference signal is greater than a bandwidth occupied by a primary synchronization signal PSS transmitted on the licensed frequency band.
10. the method of claim 8, wherein a sequence of the second synchronization reference signal carries indication information.
11. The method of claim 10, wherein the indication information indicates control information transmitted after the second synchronization reference signal.
12. the method of claim 8, wherein the first and second synchronization reference signals carry information of physical layer cell IDs corresponding to Component Carriers (CCs) of the unlicensed frequency band, and are used for cell search of neighboring cell User Equipment (UE).
13. the method of claim 8, wherein after the base station transmits the second synchronization reference signal, further comprising:
And if the second synchronous reference signal does not occupy the total bandwidth of the component carrier CC of the unauthorized frequency band, the base station sends other reference signals on other frequency domain resources except the frequency domain resource occupied by the second synchronous reference signal in the second complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unauthorized frequency band.
14. A method of synchronization, the method comprising:
User Equipment (UE) captures a first synchronous reference signal sent by a base station on a Component Carrier (CC) of an unauthorized frequency band; the first synchronization reference signal is sent by the base station on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of a CC occupying the unlicensed frequency band, and the first synchronization reference signal carries indication information;
and the UE performs initial synchronization with the CC of the unlicensed frequency band based on the acquired first synchronization reference signal.
15. The method of claim 14, wherein acquiring, by a User Equipment (UE), the first synchronization reference signal transmitted by a base station on a CC in an unlicensed frequency band comprises:
The UE receives a cell identification ID of a sequence used for scrambling a first synchronous reference signal on a Component Carrier (CC) of an authorized frequency band;
And the UE captures the first synchronous reference signal sent by the base station on the CC of the unauthorized frequency band based on the cell ID.
16. The method of claim 15, wherein the cell ID is a physical layer cell ID corresponding to a component carrier CC of the unlicensed frequency band; or the cell ID is a physical layer cell ID corresponding to the component carrier CC of the authorized frequency band.
17. The method of claim 14, wherein the method further comprises:
And the UE receives other reference signals on the OFDM symbol for transmitting the first synchronous reference signal, and synchronously tracks the Component Carrier (CC) of the unauthorized frequency band based on the received other reference signals.
18. the method of claim 14, wherein the method further comprises:
The UE captures a second synchronous reference signal sent by the base station on a Component Carrier (CC) of an unauthorized frequency band; the second synchronization reference signal is sent by the base station on a second complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the CC occupying the unlicensed frequency band;
And the UE performs initial synchronization with the CC of the unlicensed frequency band based on the acquired second synchronization reference signal.
19. The method of claim 18, wherein the method further comprises:
And the UE receives other reference signals on the OFDM symbol for transmitting the second synchronous reference signal, and synchronously tracks the component carrier CC of the unlicensed frequency band based on the received other reference signals.
20. a synchronization apparatus, characterized in that the apparatus comprises:
A configuration module for configuring a first synchronization reference signal;
a sending module, configured to send the configured first synchronization reference signal on a first complete orthogonal frequency division multiplexing OFDM symbol from a starting time of a component carrier CC of an unlicensed frequency band occupied by a base station, for initial synchronization between a user equipment UE and the component carrier CC;
the configuration module is specifically configured to: and configuring a first synchronization reference signal carrying indication information.
21. the apparatus of claim 20, wherein the configuration module is specifically configured to:
And configuring a sequence scrambled by a cell Identification (ID) for the first synchronization reference signal.
22. The apparatus of claim 20, wherein the sending module is further configured to:
and if the first synchronous reference signal does not occupy the total bandwidth of the component carrier CC of the unauthorized frequency band, sending other reference signals on other frequency domain resources except the frequency domain resource occupied by the first synchronous reference signal in the first complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unauthorized frequency band.
23. The apparatus of claim 20, wherein the configuration module is further to: configuring a second synchronization reference signal;
The sending module is further configured to: and sending the second synchronization reference signal on a second complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time, wherein the second synchronization reference signal is used for identifying that the Component Carrier (CC) of the unlicensed frequency band is occupied by the base station by an adjacent cell.
24. The apparatus of claim 23, wherein a sequence of the second synchronization reference signal carries indication information.
25. the apparatus of claim 23, wherein the first and second synchronization reference signals carry information of physical layer cell IDs corresponding to Component Carriers (CCs) of the unlicensed frequency band, and are used for cell search of neighboring cell User Equipment (UE).
26. the apparatus of claim 23, wherein the sending module is further configured to:
And if the second synchronization reference signal does not occupy the total bandwidth of the component carrier CC of the unlicensed frequency band, sending other reference signals on other frequency domain resources except the frequency domain resource occupied by the second synchronization reference signal in the second complete OFDM symbol, so that the UE can perform synchronous tracking on the component carrier CC of the unlicensed frequency band.
27. A synchronization apparatus, characterized in that the apparatus comprises:
The device comprises an acquisition module, a synchronization module and a synchronization module, wherein the acquisition module is used for acquiring a first synchronization reference signal sent by a base station on a Component Carrier (CC) of an unauthorized frequency band; the first synchronization reference signal is sent by the base station on a first complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of a CC occupying the unlicensed frequency band, and the first synchronization reference signal carries indication information;
a synchronization module, configured to perform initial synchronization with the CC in the unlicensed frequency band based on the first synchronization reference signal captured by the capture module.
28. the apparatus of claim 27, wherein the synchronization module is further to:
And receiving other reference signals on the OFDM symbol for transmitting the first synchronous reference signal, and synchronously tracking the component carrier CC of the unlicensed frequency band based on the received other reference signals.
29. The apparatus of claim 27, wherein the capture module is further to: capturing a second synchronous reference signal sent by the base station on a Component Carrier (CC) of an unauthorized frequency band; the second synchronization reference signal is sent by the base station on a second complete Orthogonal Frequency Division Multiplexing (OFDM) symbol from the starting time of the CC occupying the unlicensed frequency band;
The synchronization module is further configured to perform initial synchronization with the CC of the unlicensed frequency band based on the second synchronization reference signal captured by the capture module.
30. The apparatus of claim 29, wherein the synchronization module is further configured to:
And receiving other reference signals on the OFDM symbol for transmitting the second synchronous reference signal, and synchronously tracking the component carrier CC of the unlicensed frequency band based on the received other reference signals.
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| CN108282859B (en) * | 2017-01-06 | 2020-10-27 | 华为技术有限公司 | Communication method and device |
| CN108737309B (en) * | 2017-04-20 | 2020-10-16 | 中国移动通信有限公司研究院 | Synchronization method and device applied to 5G system |
| CN109818896A (en) * | 2017-11-20 | 2019-05-28 | 富士通株式会社 | Transmission method, device and the communication system of synchronization signal |
| CN110035491B (en) * | 2018-01-11 | 2020-06-19 | 维沃移动通信有限公司 | Synchronization indication method and device |
| CN110166393B (en) * | 2018-02-13 | 2021-06-25 | 展讯通信（上海）有限公司 | Method and device for sending and receiving synchronization signal block |
| CN110300459B (en) * | 2018-03-23 | 2021-05-18 | 维沃移动通信有限公司 | Signal transmission method and network equipment |
| US11510164B2 (en) | 2018-04-02 | 2022-11-22 | Beijing Xiaomi Mobile Software Co., Ltd. | Method and device for synchronous broadcasting transmission signal block |
| CN109039561B (en) * | 2018-07-16 | 2021-04-20 | 宇龙计算机通信科技(深圳)有限公司 | Transmission method and device for synchronous signal block index |
| CN109041199B (en) * | 2018-07-16 | 2021-03-09 | 宇龙计算机通信科技(深圳)有限公司 | Method and device for transmitting synchronization signal |
| CN113133090B (en) * | 2019-12-30 | 2023-03-31 | 大唐移动通信设备有限公司 | Signal transmission method and device |
| CN115694756A (en) * | 2021-07-29 | 2023-02-03 | 维沃移动通信有限公司 | Positioning reference signal processing method, terminal and network side equipment |
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