CN110719625A - SSB sending method and device, base station and system - Google Patents
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- H04W52/04—TPC
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/18—TPC being performed according to specific parameters
- H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
- H04W52/241—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
Abstract
The application provides a method and a device for sending an SSB, a base station and a system, comprising the following steps: and in one sending period of the SSBs, only one SSB is sent, the transmitting power of one SSB is the target transmitting power or the preset basic transmitting power, and the target transmitting power is greater than or equal to the basic transmitting power. Therefore, the terminal can detect assuming that the number of the SSBs of the cell is 1, the SSB combination operation is not needed, the complexity of terminal detection is reduced, and the detection accuracy is improved, and because the SSB subcarriers are separately subjected to DFT-s-OFDM modulation from other subcarriers, the peak-to-average ratio of signals is not increased under the condition of transmitting only one SSB, thereby ensuring the demodulation performance of the terminal.
Description
Technical Field
The present application relates to the field of wireless communications, and in particular, to a method, an apparatus, a base station, and a system for transmitting an SSB.
Background
In the process of communication between the base station and the terminal, the base station needs to send a downlink synchronization channel to the terminal, and the main function of the downlink synchronization channel is to enable the terminal to achieve frequency and symbol synchronization with the downlink synchronization channel of the Cell, obtain the starting position of a downlink co-line signal frame, and determine the PCI (Physical Cell Identity) of the Cell by detecting the downlink synchronization channel.
The downlink synchronization channel comprises: PSS (Primary synchronization signal) and SSS (Secondary synchronization signal). The PSS, the SSS, and the PBCH (physical broadcast channel) constitute an SSB (SS/PBCH block).
Because the low-orbit satellite has a very fast moving speed, a terminal can switch a cell within every 10s, and the signal-to-noise ratio of a low-orbit satellite channel is very low, as low as-10 dB, the reasonability of the downlink synchronization channel design is very important, and the terminal can rapidly and correctly perform downlink synchronization under the satellite channel condition while considering the overhead.
In the prior art, in order to ensure the correctness of the SSB detection, an SSB repeat transmission method is adopted, so that the terminal needs to perform incoherent combining operation on the repeated SSBs and generates a plurality of SSB peak values, the terminal needs to determine a first SSB position according to the SSB peak values, and the problem of an error in determining the first SSB position may occur under the conditions of low signal-to-noise ratio and rapid change of channel receiving power caused by rapid movement of a satellite.
Therefore, the existing SSB sending method increases the complexity of terminal detection and the possibility of errors.
Disclosure of Invention
The application provides a method and a device for SSB, a base station and a computer readable storage medium, aiming at solving the problem of reducing complexity and error possibility of detecting the SSB by a terminal under the condition of not increasing overhead.
In order to achieve the above object, the present application provides the following technical solutions:
a sending method of a synchronous broadcast block (SSB), comprising:
and within one sending period of the SSB, sending an SSB, wherein the sending power of the SSB is a target sending power or a preset basic sending power, the target sending power is greater than or equal to the basic sending power, and the SSB sub-carrier is separated from other sub-carriers to carry out DFT-s-OFDM modulation.
Optionally, before the sending an SSB, the method further includes:
estimating the downlink average receiving signal-to-noise ratio of the cell;
and under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, increasing a preset first numerical value of the transmitting power of the SSB on the basis of the basic transmitting power to obtain the target transmitting power of the SSB.
Optionally, the method further includes:
and reducing the transmitting power of other frequency domain subcarriers to ensure that the transmitting power of the frequency domain subcarrier for transmitting a target time slot is not larger than a preset threshold value, wherein the target time slot is the time slot in which the SSB is positioned, and the target other frequency domain subcarriers are frequency domain subcarriers except the frequency domain subcarriers occupied by the SSB in the frequency domain subcarriers for transmitting the target time slot.
Optionally, the method further includes:
reducing the code rates of the other frequency domain subcarriers, and/or changing the modulation modes of the other frequency domain subcarriers from a first mode to a second mode;
wherein the demodulation error probability of the first mode is greater than the demodulation error probability of the second mode.
Optionally, the method further includes:
and nulling other frequency domain subcarriers to ensure that the transmitting power of the frequency domain subcarrier for transmitting a target time slot is not greater than a preset threshold value, wherein the target time slot is the time slot in which the SSB is positioned, the other frequency domain subcarriers are the frequency domain subcarriers of a first number except the frequency domain subcarriers occupied by the SSB in the frequency domain carrier for transmitting the target time slot, and the first number is determined according to the first numerical value.
Optionally, the method further includes:
adding indication information in a master information block MIB or a system information block SIB, wherein the indication information is used for indicating the position of the other frequency domain subcarriers which are nulled.
Optionally, the one SSB occupies the last four OFDM symbols of one slot.
A transmitting apparatus of an SSB, comprising:
a sending unit, configured to send an SSB within one sending period of the SSB, where the transmit power of the SSB is a target transmit power or a preset basic transmit power, the target transmit power is greater than or equal to the basic transmit power, and the SSB subcarriers are separately DFT-s-OFDM modulated from other subcarriers.
A communication system, comprising:
a base station, a satellite and a terminal;
the base station is used for sending an SSB to the satellite within one sending period of the SSB, wherein the sending power of the SSB is a target sending power or a preset basic sending power, the target sending power is greater than or equal to the basic sending power, and the SSB sub-carrier is separated from other sub-carriers to carry out DFT-s-OFDM modulation;
the satellite is used for broadcasting the SSB to the terminal;
and the terminal detects and executes primary synchronization signal PSS synchronization, secondary synchronization signal SSS synchronization and physical broadcast channel PBCH demodulation according to only one SSB in the sending period of each SSB.
Optionally, the base station is further configured to:
estimating a downlink average received signal-to-noise ratio of the cell before said transmitting an SSB to said satellite; and under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, increasing a preset first numerical value of the transmitting power of the SSB on the basis of the basic transmitting power to obtain the target transmitting power of the SSB.
A base station, comprising: a processor and a memory for storing a program; the processor is configured to run the program to implement the above-mentioned SSB transmission method.
According to the technical scheme, only one SSB is sent in one sending period of the SSB, the transmitting power of one SSB is the target transmitting power or the preset basic transmitting power, and the target transmitting power is larger than or equal to the basic transmitting power. Therefore, the terminal can detect assuming that the number of the SSBs of the cell is 1, the SSB combination operation is not needed, the complexity of terminal detection is reduced, and the detection accuracy is improved, and the SSB subcarriers are separately subjected to DFT-s-OFDM modulation from other subcarriers, so that the peak-to-average ratio of signals is not increased under the condition of transmitting only one SSB, and the demodulation performance of the terminal is ensured.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic diagram of a prior art SSB transmission mode;
FIG. 2 is a graph of a peak detection result at a high signal-to-noise ratio for a prior art SSB of 4;
FIG. 3 is a graph of peak detection results at a low signal-to-noise ratio for a prior art SSB of 4;
FIG. 4 is a schematic diagram of an SSB transmission mode disclosed in an embodiment of the present application;
FIG. 5(a) is a graph of the peak detection results of SSB detection disclosed in the examples of the present application;
FIG. 5(b) is another graph of the peak detection results of SSB detection disclosed in the examples of the present application;
fig. 6 is a flowchart of a SSB transmission method disclosed in an embodiment of the present application;
fig. 7 is a flowchart of another SSB transmission method disclosed in an embodiment of the present application;
fig. 8 is a flowchart of another SSB transmission method disclosed in an embodiment of the present application;
fig. 9 is a schematic structural diagram of a transmitting apparatus of an SSB disclosed in an embodiment of the present application;
fig. 10 is a schematic structural diagram of a base station disclosed in an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The sending method of the SSB provided by the embodiment of the application can be applied to scenes such as satellite communication, broadband, 5G communication and the like.
In order to facilitate understanding of the methods provided by the embodiments of the present application, a brief description of the SSB technology involved in the present application will be provided first. In the SSB, the PSS and the SSS each occupy one OFDM symbol, and the two PBCHs each occupy one OFDM (orthogonal frequency Division Multiplex) symbol, that is, one SSB occupies four OFDM symbols in the time domain, and the four OFDM symbols are consecutive symbols. Meanwhile, in the frequency domain, one SSB occupies 20 frequency resource blocks PRB. In a slot for transmitting an SSB, 14 consecutive OFDM symbols are included, and transmitting an SSB needs to occupy 4 consecutive OFDM symbols in the slot and 20 PRBs, and other OFDM symbols occupy other frequency domain subcarriers.
Fig. 1 is a diagram illustrating an example of an SSB transmission mode in the prior art, in fig. 1, two slots (slots) are set in one transmission period n, and each slot repeatedly transmits two SSBs, that is, SSBs (SSBs 1, SSBs 2, SSBs 3, and SSBs 4 in the figure) are repeatedly transmitted 4 times for one cell in one period. In the figure, a number "0" in a slot is an OFDM symbol occupied by a reference signal CRS (Cell-specific reference signal), and a number "7" in the slot is an OFDM symbol occupied by an auxiliary reference signal CRS.
The inventor researches and discovers that when a terminal initially accesses, the terminal needs to perform incoherent combination operation on repeated SSBs, and peaks of a plurality of SSBs occur, the terminal needs to judge a first SSB position according to the peaks of the SSBs, and a judgment error of the first SSB position may occur when a Signal to Interference plus noise ratio (Signal to Interference plus noise ratio) rapidly changes due to low Signal-to-noise ratio and rapid movement of a satellite.
Fig. 2 is an exemplary diagram of a peak detection result obtained by performing non-coherent combining and detection on PSS by a terminal under a normal signal-to-noise ratio (e.g., SNR of 8dB) and a condition that a base station repeatedly transmits 4 SSBs in one period. Fig. 3 is an exemplary diagram of the equivalent detection result of the non-coherent combining and detection of PSS performed by the terminal when the signal-to-noise ratio is relatively low and there is a large frequency offset (e.g., SNR-10 dB), and the base station repeatedly sends 4 SSBs in one period. In fig. 2 and 3, the horizontal axis represents time and the vertical axis represents power values.
The application provides a method for sending an SSB, which comprises the following steps: within one transmission period of the SSB, transmitting an SSB, namely: for one cell, only one SSB is transmitted within one transmission period of the SSB. And, the SSB subcarriers are DFT-s-OFDM modulated separately from other subcarriers. And after modulation is finished, mapping each modulated subcarrier to a corresponding subcarrier position.
The transmitting power of one SSB is a target transmitting power or a preset basic transmitting power, and the target transmitting power is greater than or equal to the basic transmitting power.
Fig. 4 is a schematic diagram of an SSB transmission mode in this embodiment, and as shown in fig. 4, one SSB is sent in one cycle, that is, one slot is set in one cycle, and the SSB only occupies four consecutive OFDM symbols in one slot. Optionally, in this embodiment, the SSB transmitted each time occupies the last four symbols of one timeslot, so as to facilitate resource allocation of other downlink channels.
In this embodiment, because the base station sends one SSB in one period, the terminal only needs to configure the number of SSBs as 1 in one period, and only needs to perform one detection.
The transmission power of the SSB may be a target transmission power or a preset basic transmission power, and the transmission power of the SSB may be the basic transmission power under the condition that the downlink average received signal-to-noise ratio of the cell is high. The basic transmit power may be set according to requirements, and optionally, the basic transmit power may be a transmit power value used for transmitting the SSB in the prior art.
The target transmission power is set to be greater than the basic power, and specifically, the target transmission power is related to the downlink average received signal-to-noise ratio of the cell. The lower the downlink average received signal-to-noise ratio of the cell is, the larger the difference between the target transmitting power and the basic power is.
The target transmit power is set to be greater than the base power in order to reduce the effect of noise on SSB detection. The applicant researches the peak detection result graphs of fig. 2 and fig. 3 obtained by the SSB transmission mode adopted in the prior art, and finds that, under the condition that the number of SSBs repeatedly transmitted by the base station is the same but the signal-to-noise ratio is different, the peak value distribution in the peak detection result of fig. 3 is more irregular than that in fig. 2, and it is obvious that noise has an influence on the peak value, for example, after the noise is superimposed on the peak value position, the peak value is raised or lowered, thereby increasing the difficulty of detection. Therefore, in this embodiment, when the signal-to-noise ratio is low, the transmit power of the SSB is increased, so that the terminal can maintain the detection accuracy.
Fig. 5(a) and 5(b) are graphs of peak detection results obtained by using the method provided in this embodiment, specifically, fig. 5(a) is a graph of peak detection results corresponding to the SSB transmission power being boosted by 9dB when the signal-to-noise ratio is-10 dB, and fig. 5(b) is a graph of peak detection results corresponding to the SSB transmission power being boosted by 6dB when the signal-to-noise ratio is-10 dB.
In this embodiment, a peak detection result graph, fig. 5(a) and fig. 5(b) is obtained, and compared with the peak detection results of fig. 2 and fig. 3, a plurality of peaks appear in both fig. 2 and fig. 3, which results in that the terminal needs to determine the first SSB position according to the peaks of the SSBs, and difficulty in detection and error probability are increased.
Based on the above technical features of the present embodiment, in order not to increase the peak-to-average ratio of the signal, the SSB subcarriers are separated from other subcarriers and DFT-s-OFDM modulation is performed. Also taking fig. 4 as an example, the next four consecutive OFDM symbols occupied by SSB are separately DFT-s-OFDM modulated.
The method provided by the embodiment of the application sends one SSB in one sending period of the SSB, the transmitting power of only one SSB in one cell is the target transmitting power or the preset basic transmitting power, and the target transmitting power is greater than or equal to the basic transmitting power. In the technical scheme, only one SSB is sent by one cell in one SSB period, so that the terminal can detect assuming that the number of the SSBs of the cell is 1, and SSB combination operation is not needed, thereby reducing the complexity of terminal detection and improving the detection accuracy. And, the SSB sub-carriers are separately subjected to DFT-s-OFDM modulation to reduce the peak-to-average ratio of the transmitted signal.
Fig. 6 is another SSB sending method according to an embodiment of the present application, which may include the following steps:
s601, estimating the downlink average receiving signal-to-noise ratio of the cell.
For example, for satellite communication, the downlink average received signal-to-noise ratio of a cell may be calculated according to ephemeris information, and when there are multiple cells under one satellite, the downlink average received signal-to-noise ratio of the cell is calculated for each cell. The ephemeris information, also called ephemeris data or ephemeris, is a satellite orbit parameter table, i.e. position information and velocity information of a predetermined location of the satellite at regular intervals is described by using list data. For the scenarios of wideband and 5G communication, respective prior art calculations may be adopted, and are not described herein again.
S602, under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, the transmitting power of the SSB is increased by a preset first value on the basis of the basic transmitting power, and the transmitting power of the SSB, namely the target transmitting power, is obtained.
The first threshold is a preset value, and the first preset value can be obtained according to actual measurement. Under the condition that the downlink average received signal-to-noise ratio of the cell is lower than the first threshold, it is shown that the detection of the SSB is greatly affected due to the higher noise, and in such a condition, the preset first value is increased on the basis of the basic transmission power of the SSB. Wherein, the preset first value and: the downlink average received signal-to-noise ratio of the cell is related to the difference of the first threshold, and the lower the downlink average received signal-to-noise ratio of the cell is, the larger the first value is.
It should be noted that, in the case that the downlink average received signal-to-noise ratio of the cell is not lower than the first threshold, the transmission power of the SSB may be the basic transmission power.
S603, according to the transmitting power of the SSB, in a transmitting period of the SSB, transmitting the SSB.
After the transmission power of the SSB is determined, an SSB is transmitted according to a transmission period of the SSB.
The method provided in this embodiment may dynamically adjust the transmission power of the SSB according to the downlink average received signal-to-noise ratio of the cell, so that the SSB is transmitted with higher transmission power under the condition that the downlink average received signal-to-noise ratio of the cell is lower.
Fig. 7 is another SSB sending method according to an embodiment of the present application, which may include the following steps:
s701, estimating the downlink average receiving signal-to-noise ratio of the cell.
S702, under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, the preset first value is increased on the basis of the basic transmitting power of the SSB, and the transmitting power of the SSB, namely the target transmitting power, is obtained.
Specific implementations of S701 to S702 may refer to S601 to S602 of fig. 6.
And S703, reducing the transmitting power of other frequency domain subcarriers, so that the transmitting power of the frequency domain subcarrier of the target time slot is not greater than a preset threshold value.
The target time slot is the time slot where the SSB is located, and the other frequency domain subcarriers are frequency domain subcarriers except the frequency domain subcarriers occupied by the SSB in the frequency domain subcarriers of the transmitting target time slot.
In this embodiment, for example, one slot includes 14 OFDM symbols, and occupies 264 PRBs. Wherein, one SSB occupies 4 OFDM symbols and 20 PRBs, the remaining 10 OFDM symbols are occupied by other frequency-domain subcarriers, and the other frequency-domain subcarriers occupy 244 PRBs.
In this embodiment, optionally, the preset threshold may be total transmission power for transmitting the downlink synchronization signal in the prior art. In order to ensure that the total transmission power is not changed, the transmission power of other frequency domain subcarriers needs to be reduced under the condition that the transmission power of the SSB is increased, so that the total overhead is not increased compared with the transmission power used by the method in the present embodiment in the prior art.
For example, under the condition of an extremely low signal-to-noise ratio (SNR ═ 10dB), the transmission power of the SSB is increased by 9dB, corresponding to that the increased transmission power of the SSB is 8 times that before the increase, according to the formula (1), the ratio Y between the transmission power after the decrease of the subcarriers in other frequency domains and the transmission power before the decrease is calculated, the ratio Y is converted into a dB value, that is, the transmission power of the subcarriers in other frequency domains is decreased by 3.7dB, and the MCS (Modulation and Coding Scheme) of the PDSCH (Physical Downlink Shared Channel) is decreased by 1 to 4 orders.
The formula (1) is: y ═ sbnum-X × SsbRbNum)/(RbNum-SsbRbNum).
Y is the ratio of the transmitting power of the subcarriers of other frequency domains after the descending to the transmitting power before the descending; x is the ratio of the transmission power after SSB lifting to the transmission power before SSB lifting; RbNum is the total number of PRBs, which in this embodiment is RbNum 264; SsbRbNum is the number of PRBs occupied by SSB, and in this embodiment, SsbRbNum is 20.
S704, reducing the code rate of other frequency domain subcarriers, or changing the modulation mode of other frequency domain subcarriers from the first mode to the second mode.
After the transmission power of other frequency domain subcarriers is reduced, in order to ensure the detection accuracy of the terminal, the code rates of the other frequency domain subcarriers can be further reduced, or the modulation modes of the other frequency domain subcarriers are adjusted, so that the modulation mode is changed from the first mode to the second mode, wherein the demodulation error probability of the first mode is greater than that of the second mode, and the demodulation accuracy of the terminal is favorably increased. Of course, the modulation scheme of the other frequency domain subcarriers may be changed from the first scheme to the second scheme while reducing the code rate of the other frequency domain subcarriers.
S705, according to the transmitting power of the SSB, in a transmitting period of the SSB, transmitting an SSB.
The implementation process of S705 may refer to the foregoing embodiments, and is not described herein again.
The method provided by this embodiment ensures the correctness of the terminal detecting the SSB by increasing the transmitting power of the SSB under the condition of a low signal-to-noise ratio, and simultaneously reduces the transmitting power of the subcarriers in other frequency domains, and keeps the total transmitting power of the downlink synchronization signal unchanged, thereby ensuring that the total overhead of the transmitting power used by the method in this embodiment is not increased compared with the prior art, and further reducing the code rates of the subcarriers in other frequency domains, and/or adjusting the modulation modes of the subcarriers in other frequency domains, so that the correctness of the terminal detecting the signals on the subcarriers in other frequency domains is not affected under the condition of reducing the transmitting power of the subcarriers in other frequency domains.
In the existing SSB sending method, 4 SSBs are sent in one sending period, the number of SSBs to be sent is not dynamically adjusted according to the channel condition of the current cell, and the purpose of sending less SSBs to the cell with high downlink average receiving signal-to-noise ratio to reduce the overhead cannot be realized. In the method of this embodiment, even if the transmission power of the SSB is increased, downlink overhead is not increased compared to the prior art, so that the overhead is effectively controlled while complexity of detecting the SSB by the terminal is reduced and accuracy is improved.
Fig. 8 is another SSB sending method according to an embodiment of the present application, which may include the following steps:
s801, estimating the downlink average receiving signal-to-noise ratio of the cell.
S802, under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, the preset first value is increased on the basis of the basic transmitting power of the SSB, and the transmitting power of the SSB is obtained.
Specific implementations of S801 to S802 may refer to S601 to S602 of fig. 6.
And S803, nulling other frequency domain subcarriers to ensure that the transmitting power of the frequency domain subcarrier of the transmission target time slot is not greater than a preset threshold value.
The target time slot is the time slot where the SSB is located, and the other frequency domain subcarriers are the frequency domain subcarriers of a first number except the frequency domain subcarriers occupied by the SSB in the frequency domain subcarriers of the same OFDM symbol as the SSB in the target time slot, wherein the first number is determined according to a first numerical value. That is, the number of nulled frequency domain subcarriers is determined according to the boost value of the transmission power of the SSB, and specifically, the number of nulled frequency domain subcarriers may be calculated by referring to formula (2).
Y＝(X-1)*SSbRbNum*12 (2)
Wherein, Y is the number of the nulled frequency domain subcarriers; x is the ratio of the transmission power after SSB lifting to the transmission power before SSB lifting; the SSbRbNum is the number of PRBs occupied by the SSB, and optionally, in this embodiment, the number of PRBs occupied by the SSB is 20.
In this embodiment, in the case that the signal-to-noise ratio is low and the transmission power of the SSB is increased, in order to keep the total transmission power unchanged, other frequency domain subcarriers may be nulled, and the frequency domain subcarriers are nulled to be frequency domain subcarriers that do not transmit channels at the time slot position.
In the case where other frequency domain subcarriers are nulled, in order to enable the terminal to correctly demodulate the SSB, indication Information indicating the location of the nulled frequency domain subcarriers is added to MIB (master Information Block) or SIB (System Information Block). For example, an indication of a frequency domain subcarrier blanking pattern of the slot in which the SSB of 2 bits is added. For example, when the 2bit indication is 0, it means that there is no frequency domain subcarrier null; when the SSB transmitting power is increased by 3dB and X is 2 correspondingly, the 2bit indication is 1, which indicates that the number of the nulled subcarriers is 240; when the SSB transmission power is increased by 6dB and X is equal to 4, the 2bit indication is 2, which indicates that the number of nulled subcarriers is 720; when the SSB transmit power is increased by 9dB, corresponding to X ═ 8, the 2bit indication is 3, which means that the number of nulled subcarriers is 1680.
S804, according to the transmitting power of the SSB, in a transmitting period of the SSB, an SSB is transmitted.
After the transmitting power of the SSB is determined, one SSB is sent according to the sending period of the SSB, so that the number of the SSBs which are only configured by the terminal is 1, and the detection is performed once, thereby greatly reducing the complexity of the terminal detection.
In the method provided by this embodiment, under the condition of a low signal-to-noise ratio, the accuracy of detecting the SSB by the terminal is ensured by increasing the transmission power of the SSB, and meanwhile, other frequency domain subcarriers are nulled, and the total transmission power of the downlink signal is kept unchanged, so that it is ensured that the total overhead is not increased compared with the prior art for the transmission power used by the method described in this embodiment.
Optionally, the transmission function may also be reduced for another part of other subcarriers, that is, a part of other subcarriers is nulled, so as to ensure that the total transmission power of the frequency domain subcarriers of the transmission target time slot is not greater than the preset threshold.
Corresponding to the SSB sending method provided in the embodiment of the present application, referring to fig. 9, a schematic structural diagram of an SSB sending apparatus 90 provided in the embodiment of the present invention is shown, and the SSB sending apparatus includes:
a sending unit 901, configured to send an SSB within one sending period of the SSB, where the sending power of the SSB is a target sending power or a preset basic sending power, the target sending power is greater than or equal to the basic sending power, and the SSB subcarriers are separately DFT-s-OFDM modulated from other subcarriers.
An estimating unit 902, configured to estimate a downlink average received signal-to-noise ratio of the cell before sending the SSB; and under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, increasing a preset first value of the transmitting power of the SSB on the basis of the basic transmitting power to obtain the transmitting power of the SSB.
A first reducing unit 903, configured to reduce the transmission power of the other frequency domain subcarriers, so that the total transmission power of the frequency domain subcarriers for sending the target time slot is not greater than a preset threshold, where the target time slot is a time slot in which the SSB is located, and the other frequency domain subcarriers are frequency domain subcarriers other than the frequency domain subcarriers occupied by the SSB in the frequency domain subcarriers for sending the target time slot.
A second reducing unit 904, configured to reduce code rates of other frequency domain subcarriers, and/or change a modulation scheme of the other frequency domain subcarriers from a first scheme to a second scheme; wherein the demodulation error probability of the first mode is greater than the demodulation error probability of the second mode.
A null unit 905, configured to null other frequency domain subcarriers, so that the total transmission power of the frequency domain subcarriers that send a target time slot is not greater than a preset threshold, where the target time slot is the time slot in which the SSB is located, and the other frequency domain subcarriers are frequency domain subcarriers that transmit the target time slot, where the first number of frequency domain subcarriers is determined according to the first value, and the frequency domain subcarriers are a first number of frequency domain subcarriers outside the frequency domain subcarriers occupied by the SSB.
When other frequency domain subcarriers are nulled, nulling section 905 adds indication information to MIB or SIB, where the indication information indicates a location of the nulled other frequency domain subcarriers.
According to the sending device of the SSB, in one sending period of the SSB, one cell only sends one SSB, the sending power of one SSB is the target sending power or the preset basic sending power, and the target sending power is larger than or equal to the basic sending power. In the technical scheme, only one SSB is sent by one cell in one SSB period, so that the terminal can detect assuming that the number of the SSBs of the cell is 1, and SSB combination operation is not needed, thereby reducing the complexity of terminal detection and improving the detection accuracy.
The present application also provides a base station 10, comprising: a processor 1001 and a memory 1002, the memory 1002 is used for storing programs, and the processor 1001 is used for running the programs so as to realize the SSB transmission method described in the above embodiments.
It should be noted that the base station may be a base station in a satellite communication system, a ground gateway station, or an access network baseband processing unit (BBU).
The application also provides a communication system which comprises the base station, the satellite and the terminal. The base station is used for sending an SSB to the satellite within one sending period of the SSB, wherein the transmitting power of the SSB is a target transmitting power or a preset basic transmitting power, the target transmitting power is greater than or equal to the basic transmitting power, and the SSB sub-carrier is separated from other sub-carriers to carry out DFT-s-OFDM modulation. The satellite is used to broadcast the SSBs to the terminals. The terminal is used for detecting and executing PSS synchronization, SSS synchronization and PBCH demodulation according to the transmission period of each SSB, wherein the transmission period of each SSB is only one SSB. Specifically, the specific processes of detecting and performing PSS synchronization, SSS synchronization, and PBCH demodulation may be referred to in the prior art, and are not described herein again.
Optionally, the base station in the system is further configured to: estimating a downlink average received signal-to-noise ratio of the cell before said transmitting an SSB to said satellite; and under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, increasing a preset first numerical value of the transmitting power of the SSB on the basis of the basic transmitting power to obtain the target transmitting power of the SSB.
Further, in the case of boosting the transmission power of the SSB, the base station is further configured to: and reducing the transmitting power of other frequency domain subcarriers to ensure that the total transmitting power of the frequency domain subcarriers for transmitting the target time slot is not more than a preset threshold value, wherein the target time slot is the time slot in which the SSB is positioned, and the other frequency domain subcarriers are the frequency domain subcarriers except the frequency domain subcarriers occupied by the SSB in the frequency domain subcarriers for transmitting the target time slot.
Further, the base station is further configured to: reducing the code rates of the other frequency domain subcarriers, and/or changing the modulation modes of the other frequency domain subcarriers from a first mode to a second mode; wherein the demodulation error probability of the first mode is greater than the demodulation error probability of the second mode.
Or, in the case of boosting the transmission power of the SSB, the base station is further configured to: and nulling other frequency domain subcarriers to ensure that the total transmission power of the frequency domain subcarriers for transmitting a target time slot is not greater than a preset threshold, wherein the target time slot is the time slot in which the SSB is positioned, the other frequency domain subcarriers are the frequency domain subcarriers of a first number except the frequency domain subcarriers occupied by the SSB in the frequency domain carriers for transmitting the target time slot, and the first number is determined according to the first numerical value.
Further, the base station is further configured to: adding indication information in a master information block MIB or a system information block SIB, wherein the indication information is used for indicating the position of the other frequency domain subcarriers which are nulled.
Optionally, the base station sets the last four OFDM symbols of one time slot occupied by the SSB.
The present application further provides a computer-readable storage medium, in which instructions are stored, and when the instructions are executed on a computer, the computer is enabled to execute the SSB sending method according to the foregoing embodiment.
The functions described in the method of the embodiment of the present application, if implemented in the form of software functional units and sold or used as independent products, may be stored in a storage medium readable by a computing device. Based on such understanding, part of the contribution to the prior art of the embodiments of the present application or part of the technical solution may be embodied in the form of a software product stored in a storage medium and including several instructions for causing a computing device (which may be a personal computer, a server, a mobile computing device or a network device) to execute all or part of the steps of the method described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A method for sending a synchronous broadcast block (SSB), comprising:
and within one sending period of the SSB, sending an SSB, wherein the sending power of the SSB is a target sending power or a preset basic sending power, the target sending power is greater than or equal to the basic sending power, and the SSB sub-carrier is separated from other sub-carriers to carry out DFT-s-OFDM modulation.
2. The method of claim 1, wherein prior to said sending an SSB, further comprising:
estimating the downlink average receiving signal-to-noise ratio of the cell;
and under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, increasing a preset first numerical value of the transmitting power of the SSB on the basis of the basic transmitting power to obtain the target transmitting power of the SSB.
3. The method of claim 2, further comprising:
and reducing the transmitting power of other frequency domain subcarriers to ensure that the total transmitting power of the frequency domain subcarriers for transmitting the target time slot is not more than a preset threshold value, wherein the target time slot is the time slot in which the SSB is positioned, and the other frequency domain subcarriers are the frequency domain subcarriers except the frequency domain subcarriers occupied by the SSB in the frequency domain subcarriers for transmitting the target time slot.
4. The method of claim 3, further comprising:
reducing the code rates of the other frequency domain subcarriers, and/or changing the modulation modes of the other frequency domain subcarriers from a first mode to a second mode;
wherein the demodulation error probability of the first mode is greater than the demodulation error probability of the second mode.
5. The method of claim 2, further comprising:
and nulling other frequency domain subcarriers to ensure that the total transmission power of the frequency domain subcarriers for transmitting a target time slot is not greater than a preset threshold, wherein the target time slot is the time slot in which the SSB is positioned, the other frequency domain subcarriers are the frequency domain subcarriers of a first number except the frequency domain subcarriers occupied by the SSB in the frequency domain carriers for transmitting the target time slot, and the first number is determined according to the first numerical value.
6. The method of claim 5, further comprising:
adding indication information in a master information block MIB or a system information block SIB, wherein the indication information is used for indicating the position of the other frequency domain subcarriers which are nulled.
7. The method of any of claims 1-6, wherein the one SSB occupies the last four OFDM symbols of a slot.
8. A communication system, comprising:
a base station, a satellite and a terminal;
the base station is used for sending an SSB to the satellite within one sending period of the SSB, wherein the sending power of the SSB is a target sending power or a preset basic sending power, the target sending power is greater than or equal to the basic sending power, and the SSB sub-carrier is separated from other sub-carriers to carry out DFT-s-OFDM modulation;
the satellite is used for broadcasting the SSB to the terminal;
and the terminal detects and executes primary synchronization signal PSS synchronization, secondary synchronization signal SSS synchronization and physical broadcast channel PBCH demodulation according to only one SSB in the sending period of each SSB.
9. The system of claim 8, wherein the base station is further configured to:
estimating a downlink average received signal-to-noise ratio of the cell before said transmitting an SSB to said satellite; and under the condition that the downlink average receiving signal-to-noise ratio of the cell is lower than a first threshold value, increasing a preset first numerical value of the transmitting power of the SSB on the basis of the basic transmitting power to obtain the target transmitting power of the SSB.
10. A base station, comprising: a processor and a memory for storing a program; the processor is configured to execute the program to implement the method for transmitting SSB according to any one of claims 1 to 7.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022141007A1 (en) * | 2020-12-29 | 2022-07-07 | 海能达通信股份有限公司 | Signal transmission method and device, base station, terminal, and computer storage medium |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101488820A (en) * | 2008-01-14 | 2009-07-22 | 华为技术有限公司 | Data sending method, data receiving method and related device |
| CN101902812A (en) * | 2010-05-19 | 2010-12-01 | 景略半导体(上海)有限公司 | A kind of adaptive subcarrier transmitting power distribution system and method |
| WO2016041463A1 (en) * | 2014-09-18 | 2016-03-24 | Huawei Technologies Co., Ltd. | Common broadcast channel low papr signaling in massive mimo systems |
| CN108811086A (en) * | 2017-05-04 | 2018-11-13 | 华为技术有限公司 | PBCH transmission methods and device |
| CN108964715A (en) * | 2018-07-25 | 2018-12-07 | 北京智芯微电子科技有限公司 | The method for reducing power line carrier communication radiation interference |
| CN109041250A (en) * | 2018-07-19 | 2018-12-18 | 宇龙计算机通信科技(深圳)有限公司 | A kind of transmission method of SSB, client and base station |
| CN109391975A (en) * | 2017-08-11 | 2019-02-26 | 中兴通讯股份有限公司 | A kind of transmission power configuration, random access Poewr control method, device and equipment |
| CN109565648A (en) * | 2018-11-02 | 2019-04-02 | 北京小米移动软件有限公司 | Method for transmitting synchronizing signal and device |
| CN110235477A (en) * | 2019-04-29 | 2019-09-13 | 北京小米移动软件有限公司 | Information transferring method, device and computer readable storage medium |
-
2019
- 2019-10-18 CN CN201910995079.9A patent/CN110719625B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101488820A (en) * | 2008-01-14 | 2009-07-22 | 华为技术有限公司 | Data sending method, data receiving method and related device |
| CN101902812A (en) * | 2010-05-19 | 2010-12-01 | 景略半导体(上海)有限公司 | A kind of adaptive subcarrier transmitting power distribution system and method |
| WO2016041463A1 (en) * | 2014-09-18 | 2016-03-24 | Huawei Technologies Co., Ltd. | Common broadcast channel low papr signaling in massive mimo systems |
| CN108811086A (en) * | 2017-05-04 | 2018-11-13 | 华为技术有限公司 | PBCH transmission methods and device |
| CN109391975A (en) * | 2017-08-11 | 2019-02-26 | 中兴通讯股份有限公司 | A kind of transmission power configuration, random access Poewr control method, device and equipment |
| CN109041250A (en) * | 2018-07-19 | 2018-12-18 | 宇龙计算机通信科技(深圳)有限公司 | A kind of transmission method of SSB, client and base station |
| CN108964715A (en) * | 2018-07-25 | 2018-12-07 | 北京智芯微电子科技有限公司 | The method for reducing power line carrier communication radiation interference |
| CN109565648A (en) * | 2018-11-02 | 2019-04-02 | 北京小米移动软件有限公司 | Method for transmitting synchronizing signal and device |
| CN110235477A (en) * | 2019-04-29 | 2019-09-13 | 北京小米移动软件有限公司 | Information transferring method, device and computer readable storage medium |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022141007A1 (en) * | 2020-12-29 | 2022-07-07 | 海能达通信股份有限公司 | Signal transmission method and device, base station, terminal, and computer storage medium |
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|---|---|
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