CN112449403B - Random access channel transmission method and device in low-orbit satellite communication - Google Patents

Random access channel transmission method and device in low-orbit satellite communication Download PDF

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Publication number
CN112449403B
CN112449403B CN201910839216.XA CN201910839216A CN112449403B CN 112449403 B CN112449403 B CN 112449403B CN 201910839216 A CN201910839216 A CN 201910839216A CN 112449403 B CN112449403 B CN 112449403B
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sequence
time
frequency domain
dft
sequences
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CN112449403A (en
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方冬梅
金星
林之楠
鲁志兵
杨芸霞
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Hytera Communications Corp Ltd
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Hytera Communications Corp Ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access, e.g. scheduled or random access
    • H04W74/002—Transmission of channel access control information
    • H04W74/004—Transmission of channel access control information in the uplink, i.e. towards network
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W48/00—Access restriction; Network selection; Access point selection
    • H04W48/08—Access restriction or access information delivery, e.g. discovery data delivery
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W48/00—Access restriction; Network selection; Access point selection
    • H04W48/16—Discovering, processing access restriction or access information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access, e.g. scheduled or random access
    • H04W74/08—Non-scheduled or contention based access, e.g. random access, ALOHA, CSMA [Carrier Sense Multiple Access]
    • H04W74/0833—Non-scheduled or contention based access, e.g. random access, ALOHA, CSMA [Carrier Sense Multiple Access] using a random access procedure

Abstract

The invention provides a random access channel transmission method in low-orbit satellite communication, which comprises the following steps: selecting a PN sequence in a set sequence form from the set PN sequence set; mapping the PN sequence to subcarriers according to a preset conversion mode; and performing inverse fast fourier transform on the subcarriers mapped with the PN sequences, transforming the subcarriers mapped with the PN sequences into a time domain, and transmitting to a base station in a predetermined form. The method provided by the invention adopts the PN sequence in the set sequence form to bear the signal to be transmitted, replaces the ZC sequence adopted by the prior Preamble sequence, avoids the condition of occurrence of a false peak in the transmission process, can more effectively identify the main peak, ensures that the terminal can access the base station in time, and ensures that the base station can effectively receive the signal. In the method provided by the embodiment of the invention, the PN sequence is adopted, so that the CP does not need to be transmitted when the PN sequence is transmitted to the base station, and the time expenditure is saved.

Description

Random access channel transmission method and device in low-orbit satellite communication
Technical Field
The present invention relates to the field of low-orbit satellite communications, and in particular, to a method and apparatus for transmitting a random access channel in low-orbit satellite communications.
Background
With the development of communication technology, people have an increasing demand for information real-time. Satellite communication has become an essential important means for global communication by virtue of numerous advantages such as wide coverage, large communication capacity, good transmission quality and the like.
The PRACH in satellite communication is mainly used for estimating uplink transmission timing error, estimating uplink frequency offset error and estimating SNR when a user accesses. The satellite channel has the characteristics that the coverage area of the satellite wave beam is very large, the satellite wave beam has an area of 60km by 1000km, and the uplink timing error is very large before uplink timing is not carried out; the motion speed of satellite communication and the carrier frequency adopted can cause very large uplink frequency offset error, and the residual uplink frequency offset is about +/-30 kHz; also, the signal-to-noise ratio of satellite communications is low, up to-10 dB at the minimum.
Whereas the transmit power of PRACH will be lower than that of other channels, typically more than ten dB lower than PUSCH.
Since satellite communication has a problem of frequent handover, and PRACH needs to be transmitted frequently, rationality of PRACH design is very important.
The channel structure of the existing PRACH comprises three parts, including 3 parts, CP, preamble and GT. The CP is configured to cancel interference caused by different arrival of each user, the Preamble is a random access sequence, and the GT is configured to prevent the Preamble from interfering with a signal transmitted subsequently. The existing Preamble sequence adopts ZC (Zadoff-Chu) sequence to carry the signal to be transmitted. Through research on the existing transmission process, the ZC sequence can generate a pseudo peak when the frequency deviation exists, and when the frequency deviation exceeds half of the subcarrier interval, the energy of the pseudo peak is even larger than that of the main peak, so that the main peak of a transmission signal can not be determined, and the signal can not be effectively received.
The frequency offset of satellite communication is as high as ±30kHz, and even if a Preamble configuration with a subcarrier interval of 60kHz is adopted in such frequency offset, the main peak may not be accurately determined. Meanwhile, when the subcarrier spacing is large, the more frequency domain RBs are occupied, resulting in an increase in overhead for PRACH. For example, the subcarrier spacing of 30kHz occupies 18 RBs; the subcarrier spacing 60kHz occupies 35 RBs.
Disclosure of Invention
The invention aims to solve the technical problem of providing a random access channel transmission method in low-orbit satellite communication, which adopts a PN sequence in a set form to bear signals to be transmitted, avoids the condition of occurrence of false peaks in the transmission process, can directly determine the main peak of the transmitted signals, and enables a terminal to be accessed into a base station in time so as to effectively receive the signals.
The invention also provides a random access channel transmission device in low-orbit satellite communication, which is used for ensuring the realization and application of the method in practice.
A random access channel transmission method in low-orbit satellite communication, the method being applied to a terminal, the method comprising:
selecting a PN sequence in a set sequence form from the set PN sequence set;
Mapping the PN sequence to subcarriers according to a preset conversion mode;
and performing Inverse Fast Fourier Transform (IFFT) on the subcarriers mapped with the PN sequences to transform the subcarriers mapped with the PN sequences to a time domain and transmitting to a base station in a predetermined form.
In the above method, optionally, if the sequence form of the PN sequence is a frequency domain PN sequence;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
the frequency domain PN sequence is directly mapped to the subcarrier.
In the above method, optionally, if the sequence form of the PN sequence is a discrete fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM modulated PN sequence;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
performing fast fourier transform on the DFT-s-OFDM modulated PN sequence to transform the DFT-s-OFDM modulated PN sequence to a frequency domain;
mapping the PN sequence of the DFT-s-OFDM modulation transformed to the frequency domain onto the subcarrier.
In the above method, optionally, if the sequence form of the PN sequence is a frequency domain PN sequence associated with a walsh orthogonal code;
The mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
and directly mapping the frequency domain PN sequence associated with the walsh orthogonal code onto the subcarriers.
In the above method, optionally, if the sequence form of the PN sequence is a discrete fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM modulated PN sequence associated with a walsh orthogonal code;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
performing fast fourier transform on the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to transform the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to a frequency domain;
mapping the PN sequence of the DFT-s-OFDM modulation which is transformed to the frequency domain and is associated with the walsh orthogonal code onto the subcarriers.
The above method, optionally, after transforming the DFT-s-OFDM modulated PN sequence into the frequency domain, before mapping the DFT-s-OFDM modulated PN sequence transformed into the frequency domain onto the subcarrier, further includes:
and windowing the PN sequence modulated by DFT-s-OFDM converted to the frequency domain.
The above method, optionally, after transforming the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to the frequency domain, before mapping the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code transformed to the frequency domain onto the subcarriers, further includes:
Windowing is performed on the PN sequence which is transformed to the frequency domain and is modulated by DFT-s-OFDM and is associated with the Walsh orthogonal code.
The method, optionally, the transmitting to the base station in a predetermined form includes:
the PN sequence converted to the time domain is transmitted to the base station in the form that the PN sequence is provided with ZP before and GT after, the ZP is a null field, and the length of the ZP is 1-2 times of the length of the CP of the OFDM symbol of the data area.
A random access channel transmission apparatus in low-orbit satellite communication, the apparatus being applied to a terminal, the apparatus comprising:
a selecting unit, configured to select a set type of PN sequence from the set PN sequence set;
a mapping unit, configured to map the PN sequence onto a subcarrier according to a preset transformation manner;
and a transmitting unit for performing Inverse Fast Fourier Transform (IFFT) on the sub-carriers mapped with the PN sequences to transform the sub-carriers mapped with the PN sequences to a time domain and transmitting the sub-carriers to a base station in a predetermined form.
A random access channel transmission method in low-orbit satellite communication, the method being applied to a base station, the method comprising:
acquiring time-frequency resource data;
Respectively correlating PN sequences in the form of each set sequence in the set PN sequences with the time-frequency resource data so as to detect peaks in the time-frequency resource data;
and when the peak value in the time-frequency resource data is detected, determining the PN sequence in the set sequence form which is currently related to the time-frequency resource data as the PN sequence sent by the terminal.
In the above method, optionally, the correlating the PN sequences in the set sequence form of each set PN sequence set with the time-frequency resource data includes:
dividing PN sequences in the set sequence form in the set PN sequence set into a plurality of PN sequence subsections;
and respectively correlating each PN sequence sub-segment of the PN sequence in the form of each set sequence with the time domain resource data, wherein the correlation comprises a time domain sliding correlation and a frequency domain correlation.
A random access channel transmission apparatus in low-orbit satellite communication, the apparatus being applied to a base station, comprising:
the acquisition unit is used for acquiring time-frequency resource data;
the detection unit is used for respectively correlating PN sequences in the set sequence forms in the set PN sequence sets with the time-frequency resource data so as to detect peaks in the time-frequency resource data;
And the determining unit is used for determining the PN sequence in the set sequence form which is currently related to the time-frequency resource data as the PN sequence sent by the terminal when the peak value in the time-frequency resource data is detected.
Compared with the prior art, the invention has the following advantages:
the invention provides a random access channel transmission method in low-orbit satellite communication, which comprises the following steps: selecting a PN sequence in a set sequence form from the set PN sequence set; mapping the PN sequence to subcarriers according to a preset conversion mode; and performing Inverse Fast Fourier Transform (IFFT) on the subcarriers mapped with the PN sequences to transform the subcarriers mapped with the PN sequences to a time domain and transmitting to a base station in a predetermined form. The random access channel transmission method provided by the invention adopts the PN sequence in the set sequence form to bear the signal to be transmitted, replaces the ZC sequence adopted by the existing Preamble sequence, avoids the condition of occurrence of a false peak in the transmission process, can more effectively identify the main peak, ensures that the terminal can access the base station in time, and ensures that the base station can effectively receive the signal. In the method provided by the embodiment of the invention, the PN sequence is adopted, so that the CP does not need to be transmitted when the PN sequence is transmitted to the base station, and the time expenditure is further saved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort to a person skilled in the art.
Fig. 1 is a flow chart of a method for transmitting a random access channel in low-orbit satellite communication according to the present invention;
fig. 2 is a schematic structural diagram of a random access channel transmission device in low-orbit satellite communication according to the present invention;
fig. 3 is a flowchart of another method of transmitting a random access channel in low-orbit satellite communication according to the present invention;
fig. 4 is another schematic structural diagram of a random access channel transmission method in low-orbit satellite communication according to the present invention;
fig. 5 is a schematic structural diagram of a random access channel transmission system in low-orbit satellite communication according to the present invention;
fig. 6 is a communication schematic diagram of a random access channel transmission system in low-orbit satellite communication according to the present invention;
Fig. 7 is a schematic structural diagram of an electronic device according to the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention is operational with numerous general purpose or special purpose computing device environments or configurations. For example: personal computers, server computers, hand-held or portable devices, tablet devices, multiprocessor devices, distributed computing environments that include any of the above devices or devices, and the like.
The embodiment of the invention provides a random access channel transmission method in low-orbit satellite communication, an execution subject of the method can be a processor in a terminal, and a method flow chart of the random access channel transmission method in the low-orbit satellite communication provided by the embodiment of the invention is shown in fig. 1, and the method flow chart comprises the following steps:
s101: selecting a PN sequence in a set sequence form from the set PN sequence set;
In the method provided by the embodiment of the invention, a PN sequence set is provided, wherein a plurality of PN sequences in the set sequence form are arranged in the PN sequence set, and the set form of each PN sequence in the PN sequence set is the same. The PN sequences in the PN sequence set can be set into a plurality of different sequence forms. In the method provided by the embodiment of the invention, the base station and each terminal can read PN sequences in the set sequence form in the PN sequence set. When the terminal needs to transmit the random access channel, a PN sequence in a set sequence form can be selected from the PN sequence set, and the actual selection process can be selected randomly after the sequence form of each PN sequence in the PN sequence set is set according to the data type to be transmitted.
S102: mapping the PN sequence to subcarriers according to a preset conversion mode;
in the method provided by the embodiment of the invention, aiming at the composition of the CP, the Preamble sequence and the GT adopted by the random access channel, the PN sequence selected in the PN sequence set is adopted to replace the original ZC sequence in the Preamble sequence, and the selected PN sequence is mapped to the subcarrier according to a preset conversion mode in the transmission process of the random access channel.
S103: and performing Inverse Fast Fourier Transform (IFFT) on the subcarriers mapped with the PN sequences to transform the subcarriers mapped with the PN sequences to a time domain and transmitting to a base station in a predetermined form.
In the method provided by the embodiment of the invention, in the transmission process of the random access channel, the subcarrier mapped with the PN sequence is required to be subjected to inverse fast Fourier transform, the subcarrier mapped with the PN sequence is transformed into the time domain, the time-frequency resource data corresponding to the subcarrier mapped with the PN sequence in the time domain is obtained, and the time-frequency resource data is transmitted to the base station in a preset form.
When a terminal needs to access a base station to send a data signal to the base station, the random access channel transmission method provided by the embodiment of the invention selects a PN sequence in a set sequence form from a set PN sequence set as a signal bearing sequence of a Preamble sequence in a random access channel, maps the selected PN sequence onto a subcarrier in a certain conversion mode, then carries out fast Fourier inverse transformation on the subcarrier mapped with the PN sequence, converts the subcarrier into a time domain, and transmits time-frequency resource data converted into the time domain to the base station in a preset form, so as to realize the transmission process of the application random access channel.
The method provided by the embodiment of the invention is realized on the basis of researching the prior random access channel transmission process, in the prior realization process, the ZC sequence adopted by the Preamble sequence can generate a pseudo peak when the frequency deviation exists, and when the frequency deviation exceeds half of the subcarrier interval, the energy of the pseudo peak is even larger than that of the main peak. Even if the frequency offset is equal to half the subcarrier spacing, if there are timing deviations, additive white gaussian noise, phase noise, etc., the energy of the pseudo-peak is lower than that of the main peak. The frequency offset of satellite communication is as high as ±30kHz, and even if a Preamble configuration with a subcarrier interval of 60kHz is adopted in such frequency offset, the main peak may not be accurately determined. Meanwhile, when the subcarrier spacing is large, the more frequency domain RBs are occupied, resulting in an increase in overhead for PRACH. For example, the subcarrier spacing of 30kHz occupies 18 RBs; the subcarrier spacing 60kHz occupies 35 RBs.
On the premise of the technical background, in the random access channel transmission method in low-orbit satellite communication provided by the embodiment of the invention, the PN sequence is adopted to replace the ZC sequence in the Preamble sequence, in the method provided by the embodiment of the invention, the PN sequence set is preset, the PN sequence set is provided with a preset number of PN sequences, the sequence forms of all PN sequences in the PN sequence set are the same, for example, the sequence forms of all PN sequences in the PN sequence set are frequency domain PN sequences. The sequence content of each PN sequence in the PN sequence set is different. The PN sequence set provided by the embodiment of the invention can be arranged in the terminal or the base station, preferably can be arranged in a local third-party system, and the terminal and the base station can access the PN sequence set.
In the method provided by the embodiment of the present invention, a plurality of sequence forms may be set for each PN sequence in the PN sequence set, and preferably, in the method provided by the embodiment of the present invention, four kinds of PN sequence sets with different sequence forms are set, and may be respectively:
the PN sequence is in the form of a frequency domain PN sequence;
the PN sequence is in the form of discrete Fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM modulated PN sequence;
the PN sequence is in the form of a frequency domain PN sequence associated with a walsh orthogonal code;
the PN sequence is in the form of a discrete Fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM modulated PN sequence associated with a walsh orthogonal code.
The PN sequences in the four sequence forms correspond to four PN sequence sets respectively, and can be set according to the type of data signals actually required to be transmitted in the specific random access channel transmission process.
When the random access channel transmission method provided by the embodiment of the invention adopts the frequency domain PN sequence, the transmitting power of the PRACH is lower, so that the problem of time domain peak-to-average ratio caused by the frequency domain PN sequence can be considered to be acceptable to a certain extent. Therefore, in the actual transmission process, the PN sequence in the set form needs to be mapped to the subcarriers in a certain manner in the frequency domain. The peak-to-average ratio is relatively low when using a PN sequence modulated by DFT-s-OFDM or a combination of PN sequence modulated by DFT-s-OFDM and Walsh code, and the effect on random access channel transmission is negligible in the scheme provided by the invention.
In a specific implementation process, when the selected sequence form of the PN sequence is a frequency domain PN sequence, mapping the PN sequence onto a subcarrier according to a preset transformation mode includes:
the frequency domain PN sequence is directly mapped to the subcarrier.
In the method provided by the embodiment of the invention, a plurality of users are supported to carry out random access by using different PN sequences in the same PRACH time-frequency resource. The PN sequences for the frequency domain can be mapped directly onto their corresponding subcarriers. The process is suitable for PN sequences in four different sequence forms provided by the embodiment of the invention, and after the PN sequences are transformed into a frequency domain, the PN sequences of a plurality of users can be allowed to be randomly accessed.
In an actual implementation process, in the method provided by the embodiment of the present invention, when the sequence form of the PN sequence is a frequency domain PN sequence, 64 PN sequences may be set in the PN sequence set, each PN sequence uses a different sequence initialization ID, and each PN sequence is 512 points.
In the transmitting process, the terminal can select one PN sequence from 64 PN sequences, map the PN sequence to the corresponding subcarrier with 30kHz interval, occupy 12 RB positions in total, and then do IFFT transformation to the time domain for transmitting.
In the method provided by the embodiment of the invention, before mapping the frequency domain PN sequence onto the subcarrier, windowing processing can be performed on the frequency domain PN sequence, wherein the windowing processing can be Hamming window or root raised cosine window and the like.
In the method provided by the embodiment of the invention, the subcarrier can be understood as a subcarrier corresponding to the PN sequence selected in the transmission process.
In a specific implementation process, when the sequence form of the PN sequence is a PN sequence modulated by discrete Fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
performing fast fourier transform on the DFT-s-OFDM modulated PN sequence to transform the DFT-s-OFDM modulated PN sequence to a frequency domain;
mapping the PN sequence of the DFT-s-OFDM modulation transformed to the frequency domain onto the subcarrier.
In the method provided by the embodiment of the invention, when the sequence form of each PN sequence in the PN sequences is PN sequence modulated by DFT-s-OFDM, 64 PN sequences can be set in the PN sequence set, each PN sequence has the sequence form of PN sequence modulated by DFT-s-OFDM, each PN sequence uses different sequence initialization IDs, and each PN sequence is 512 points.
In the transmitting process, the terminal can select one PN sequence from 64 PN sequences, then perform 512-point fast Fourier transform FFT to transform the PN sequence modulated by DFT-s-OFDM to a frequency domain, and then map the PN sequence to a corresponding subcarrier with 30kHz interval, wherein the PN sequence occupies 12 RB positions in total. In the method provided by the embodiment of the invention, in order to reduce the interference to the PUSCH of other subcarriers, after transforming the PN sequence modulated by DFT-s-OFDM to the frequency domain, windowing is performed on the PN sequence modulated by DFT-s-OFDM transformed to the frequency domain before mapping the PN sequence modulated by DFT-s-OFDM transformed to the frequency domain to the subcarriers.
The windowing process can be Hamming window or root raised cosine window, and the like, and then IFFT is performed to transmit the signals to the time domain.
In the method provided by the embodiment of the invention, if the sequence form of the PN sequence is a frequency domain PN sequence associated with a walsh orthogonal code;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
and directly mapping the frequency domain PN sequence associated with the walsh orthogonal code onto the subcarriers.
In the method provided by the embodiment of the invention, the association mode of the frequency domain PN sequence and the walsh orthogonal code can be a mode of frequency domain PN sequence+walsh orthogonal code.
In the form of frequency domain PN sequence + walsh orthogonal code, 4 frequency domain PN sequences may be set, each using a different sequence initialization ID, each of which is 512 points. And setting 16 Walsh codes with the length of 16, wherein the total number of the combinations of the frequency domain PN sequences and the Walsh codes is 64, and 64 frequency domain PN sequences associated with Walsh orthogonal codes are in the PN sequence set.
In the transmitting process, the terminal can select one from the combination of 64 frequency domain PN sequences and walsh codes, map the selected combination to the corresponding sub-carriers with 30kHz intervals, occupy 12 RB positions in total, and then perform IFFT transformation to transmit the result to the time domain. The sequence form of the frequency domain PN sequence and the Walsh code can be directly mapped to the subcarrier corresponding to the PN sequence.
In the method provided by the embodiment of the invention, before the combination of the frequency domain PN sequence and the walsh code is mapped to the subcarrier, windowing processing can be performed on the combination of the frequency domain PN sequence and the walsh code, and the windowing processing can be Hamming window or root raised cosine window and the like.
In the method provided by the embodiment of the invention, when the sequence form of the PN sequence is the PN sequence modulated by the discrete Fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM associated with the walsh orthogonal code;
The mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
performing fast fourier transform on the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to transform the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to a frequency domain;
mapping the PN sequence of the DFT-s-OFDM modulation which is transformed to the frequency domain and is associated with the walsh orthogonal code onto the subcarriers.
In the method provided by the embodiment of the invention, the association mode of the PN sequence modulated by DFT-s-OFDM and the walsh orthogonal code can be the form of PN sequence +walsh code modulated by DFT-s-OFDM.
In the form of DFT-s-OFDM modulated PN sequence + walsh code, 4 DFT-s-OFDM modulated PN sequences may be set, each using a different sequence initialization ID. Each DFT-s-OFDM modulated PN sequence is 512 points and 16 length 16 walsh codes are set. The combination of the PN sequence and the Walsh code of DFT-s-OFDM modulation is totally 64. The PN sequence set contains 64 PN sequences which are modulated by DFT-s-OFDM and are associated with Walsh codes.
In the transmitting process of the terminal, one of 64 combinations of PN sequences of DFT-s-OFDM modulation and walsh codes can be selected, then 512-point FFT is performed, the PN sequences of DFT-s-OFDM modulation associated with the walsh orthogonal codes are transformed into a frequency domain and mapped to subcarriers corresponding to 30kHz intervals, and a total of 12 RB positions are occupied.
In the method provided by the embodiment of the invention, in the form of PN sequence +walsh code of DFT-s-OFDM modulation, in order to reduce interference to PUSCH of other subcarriers, after transforming PN sequence of DFT-s-OFDM modulation associated with walsh orthogonal code to frequency domain, the PN sequence of DFT-s-OFDM modulation associated with walsh orthogonal code transformed to frequency domain is subjected to windowing treatment before mapping to the subcarriers.
The windowing process may be a hamming window or a root raised cosine window, etc.
After windowing, IFFT is performed to transmit the signals to the time domain.
In the background that the existing Preamble sequence adopts the ZC sequence based on OFDM, the ZC sequence needs a CP length, wherein the CP length is longer, the CP at 30kHz is the Preamble symbol to be repeated 3 times, and 60kHz is the Preamble symbol to be repeated 12 times. And each time a Preamble symbol occurs, a main peak and a pseudo peak appear, and the final result is that a plurality of peaks appear, so that the difficulty of judging the first peak and the difficulty of distinguishing the multi-user peaks are increased. Therefore, in the random access channel transmission method provided by the embodiment of the present invention, no matter what kind of sequence form of PN sequence is used for transmission, no CP is needed in the process of mapping the PN sequence to the subcarrier and transmitting the PN sequence, but ZP (Zero-Padding) is added before the Preamble symbol, where the length of ZP is 1-2 times the CP length of the OFDM symbol of the data area, for example, in the satellite communication protocol, the CP of the OFDM symbol of the data area is 0.59us, the CP of the OFDM symbol of the Preamble is 200us, and the length of ZP is 0.59 us-1.18 us. The ZP is used to avoid interference of the delay of the uplink symbol of other users to the Preamble symbol of the user. Since the other users have already performed uplink synchronization when transmitting the uplink symbol, the delay generally does not exceed the CP length of the normal OFDM symbol, so the length of ZP is set to 1-2 times the CP length of the data area OFDM symbol.
In the method provided by the embodiment of the invention, the GT is reserved to avoid the interference to the subsequent signal symbols.
In summary, in the method provided in the embodiment of the present invention, the transmitting to the base station in a predetermined form includes:
the PN sequence converted to the time domain is transmitted to the base station in the form that the PN sequence is provided with ZP before and GT after, the ZP is a null field, and the length of the ZP is 1-2 times of the length of the CP of the OFDM symbol of the data area.
In the method provided by the embodiment of the invention, after the selected PN sequence is transformed to the time domain, time-frequency resource data after the selected PN sequence is transformed to the time domain is obtained, ZP is set before the time-frequency resource data, GT is set after the time-frequency resource data, and the time-frequency resource data is sent to the base station.
In the method provided by the embodiment of the invention, after PN sequences are adopted, preamble CP with larger time cost is not needed, ZP with smaller time is needed, and the time cost is saved.
Corresponding to the method shown in fig. 1, the embodiment of the present invention further provides a random access channel transmission device in a low-orbit communication satellite, which is used for implementing the method in fig. 1, where the random access channel transmission device provided in the embodiment of the present invention may be applied to a computer terminal or various mobile devices, and a schematic structural diagram of the random access channel transmission device is shown in fig. 2, and the device includes:
A selecting unit 201, configured to select a PN sequence in a set form from the set PN sequence set;
a mapping unit 202, configured to map the PN sequence onto a subcarrier according to a preset transformation manner;
a transmitting unit 203, configured to perform inverse fast fourier transform IFFT on the subcarrier mapped with the PN sequence, so as to transform the subcarrier mapped with the PN sequence into a time domain, and transmit the subcarrier to a base station in a predetermined form.
When a terminal needs to send a data signal to a base station, the random access channel transmission device provided by the embodiment of the invention selects a PN sequence in a set sequence form from a set PN sequence set as a signal bearing sequence of a Preamble sequence in the random access channel, maps the selected PN sequence onto a subcarrier according to a certain conversion mode, then carries out fast Fourier inverse transformation on the subcarrier mapped with the PN sequence, converts the subcarrier into a time domain, and transmits time-frequency resource data converted into the time domain to the base station in a preset form, so as to realize the transmission process of the application random access channel.
Referring to fig. 3, the embodiment of the present invention further provides a process for implementing a random access channel transmission method in low-orbit satellite communication on a base station side, where an execution body of the random access channel transmission method implemented on the base station side may be a processor at the base station, where the processor may read each PN sequence in a set PN sequence set, and the method includes:
s301: acquiring time-frequency resource data;
in the method provided by the embodiment of the invention, when the terminal transmits the time domain signal to the base station, the base station side acquires the time-frequency resource data transmitted by the terminal, wherein the time-frequency resource data is corresponding to the time-frequency resource data after the PN sequence selected by the terminal side is mapped to the time domain, and the GT is arranged behind the time-frequency resource data.
S302: respectively correlating PN sequences in the form of each set sequence in the set PN sequences with the time-frequency resource data so as to detect peaks in the time-frequency resource data;
in the method provided by the embodiment of the invention, a processor at a base station side reads PN sequences in each set sequence form in a set PN sequence set one by one, and correlates each read PN sequence in each set sequence form with the time-frequency resource data respectively so as to detect the peak value in the time-frequency resource data. It should be noted that, the set of PN sequences read by the base station side and the set of PN sequences read by the terminal side are the same set of PN sequences.
S303: and when the peak value in the time-frequency resource data is detected, determining the PN sequence in the set sequence form which is currently related to the time-frequency resource data as the PN sequence sent by the terminal.
In the method provided by the embodiment of the invention, when the peak value in the time-frequency resource data is detected, the PN sequence in the set sequence form which is related with the time-frequency resource data at present can be determined as the PN sequence adopted by the terminal, and the terminal can be allowed to access the base station.
In the random access channel transmission method in low-orbit satellite communication provided by the embodiment of the invention, after the time-frequency resource data sent by the terminal side is acquired at the base station side, the peak value in the time-frequency resource data is detected by acquiring PN sequences in all set forms in the set PN sequence set and carrying out a correlation mode on the acquired PN sequences, so that the PN sequence adopted by the terminal side is determined, and the terminal is allowed to access the base station through the PN sequence, thereby realizing effective receiving of signals by the base station.
In the method provided by the embodiment of the present invention, the correlating the PN sequences in the set sequence form in the set PN sequence set with the time-frequency resource data includes:
Dividing PN sequences in the set sequence form in the set PN sequence set into a plurality of PN sequence subsections;
and respectively correlating each PN sequence sub-segment of the PN sequence in the form of each set sequence with the time domain resource data, wherein the correlation comprises a time domain sliding correlation and a frequency domain correlation.
In order to describe the above peak detection process in more detail, the following examples are provided in the embodiments of the present invention, and the related process will be described in detail:
first example
When the set format of the PN sequence selected by the terminal in the PN sequence set is the frequency domain PN sequence, the base station side executes the following operations:
the receiving end of the base station intercepts the Preamble symbol + GT length (ZP part data is not intercepted), obtains the data corresponding to the time-frequency resource, traverses the local 64 PN sequences, and makes segmentation correlation with the received PRACH data, for example, the segmentation number is 4, namely, the data of which the number of the segments is 512 is divided into 4 segments of 128 points, and respectively correlates with the transmitting data. Wherein the correlation may be both a time-domain sliding correlation and a frequency-domain correlation. And obtaining the PN sequence sent by the terminal and the corresponding timing deviation TO position when the peak value is searched. The frequency deviation FO can be calculated through the phase difference of the 4 sections of correlation values corresponding to the peak value.
The specific implementation process is as follows:
let the PRACH time domain signal received by the base station be y (N) and set the length as N PSS The time domain sequence corresponding to a local PN frequency domain sequence (including Preamble symbol+gt length) is s (n), n=0,..511 (IFFT transformation of the PN frequency domain sequence).
The time domain segmentation correlation method when the set form of the PN sequence is the frequency domain PN sequence is as follows:
calculation ofFinding an effective peak value in R (n), if the effective peak value occurs, representing that a user transmits PRACH by using the PN sequence, setting the n value of R (n) corresponding to the peak value to be n peak ，n peak I.e. the corresponding timing offset TO position. Calculation ofThe frequency deviation FO is +.>
The corresponding frequency domain segment correlation method is as follows:
setting vectorsThis is transformed into the frequency domain, resulting in a vector fs (l), l=0, 3 of 1×256. Setting vectorsTransforming it into the frequency domain, resulting in a vector fy (i) of 1 x 256,/i>Then calculating fsy (i, l) =<fy(i)，conj(fs(l))>Where conj (·) represents conjugating each element of the vector,<·，·>representing the dot product of the two vectors. Then, fsy (i, l) is transformed to the time domain to obtain a vector tsy (i, l) of 1×256, the first 128 elements of the vector are taken to obtain a vector r (i, l) of 1×128, and each element in r (i, l) is set as r (i, l, m), m=0. Calculation of Finding an effective peak value in R (n), if the effective peak value occurs, representing that a user transmits PRACH by using the PN sequence, setting the n value of R (n) corresponding to the peak value to be n peak ，n peak I.e. the corresponding timing offset TO position. Calculation ofFrequency deviation FO of
Second example
When the set format of the PN sequence selected by the terminal in the PN sequence set is the PN sequence modulated by DFT-s-OFDM, the base station side executes the following operations:
the receiving end of the base station intercepts the Preamble symbol + GT length (the ZP part data is not intercepted), obtains the data corresponding to the time-frequency resource, traverses the local 64 PN sequences, and makes segmentation correlation with the received PRACH data, for example, the segmentation number is 4, namely, the data of which the number of the segments is 512 is divided into 4 segments of 128 points, and respectively correlates with the transmitting data. Wherein the correlation may be both a time-domain sliding correlation and a frequency-domain correlation. And obtaining the PN sequence sent by the terminal and the corresponding timing deviation TO position when the peak value is searched. The frequency deviation FO can be calculated through the phase difference of the 4 sections of correlation values corresponding to the peak value. The time domain sliding correlation and frequency domain correlation methods are similar to the first example, and are not described herein, and a person skilled in the art can understand the actual process of the second example based on the first example, where the difference is a time domain sequence s (n), n=0, and 511 is a local PN sequence.
Third example
When the set format of the PN sequence selected by the terminal in the PN sequence set is frequency domain PN sequence+Walsh code, the base station side executes the following operations:
the receiving end of the base station intercepts the Preamble symbol and the GT length (the ZP part data is not intercepted), obtains the data corresponding to the time-frequency resource, traverses the combination of the local 64 PN sequences and the Walsh codes, and performs segmentation correlation on each combination of the PN sequences and the Walsh codes and the received PRACH data, for example, the segmentation number is 4, namely, the data of which the number of the segments is divided into 4 segments of 128 points is respectively related with the transmitting data. Wherein the correlation may be both a time-domain sliding correlation and a frequency-domain correlation. And obtaining the PN sequence sent by the terminal and the corresponding timing deviation TO position when the peak value is searched. The frequency deviation FO can be calculated through the phase difference of the 4 sections of correlation values corresponding to the peak value. The time domain sliding correlation and frequency domain correlation methods are similar to those of the first embodiment, and are not described herein, and those skilled in the art can understand the actual process of the second embodiment based on the first embodiment, unlike the first embodiment, the third embodiment is different from the codeword of the first embodiment.
Fourth example
When the set format of the PN sequence selected by the terminal in the PN sequence set is PN sequence +walsh code modulated by DFT-s-OFDM, the base station side executes the following operations:
The receiving end of the base station intercepts the Preamble symbol and the GT length (the ZP part data is not intercepted), obtains the data corresponding to the time-frequency resource, traverses the combination of the local 64 PN sequences and the Walsh codes, and performs segmentation correlation on each combination of the PN sequences and the Walsh codes and the received PRACH data, for example, the segmentation number is 4, namely, the data of which the number of the segments is divided into 4 segments of 128 points is respectively related with the transmitting data. Wherein the correlation may be both a time-domain sliding correlation and a frequency-domain correlation. And obtaining the PN sequence sent by the terminal and the corresponding timing deviation TO position when the peak value is searched. The frequency deviation FO can be calculated through the phase difference of the 4 sections of correlation values corresponding to the peak value. The time domain sliding correlation and frequency domain correlation methods are similar to the second example except that the codewords are different.
In the method provided by the embodiment of the invention, PN sequences or PN sequences plus Walsh orthogonal codes are used as random access code words in low-orbit satellite communication. Multiple users are supported to carry out random access by using different PN sequences and Walsh orthogonal codes in the same PRACH time-frequency resource. No CP is required before PRACH, only a relatively short ZP is required.
In the method provided by the embodiment of the invention, the sequence for generating the uplink PRACH in the satellite communication protocol is changed into the PN sequence or PN sequence plus the Walsh sequence from the ZC sequence, so that the problem of multimodal value of the ZC sequence under high frequency bias is avoided, the detection success probability, the TA estimation precision and the frequency bias estimation precision are greatly improved under multiple users, and the time length occupied by the PRACH channel can be reduced.
In the method provided by the embodiment of the invention, on the basis of the second example, a simulation experiment is performed, the frequency offset is set to 30kHz, the SNR= -10dB, only one peak value appears in the test process, and the estimated frequency offset is 31.67kHz.
The peak is clearer when the frequency offset is set to 30kHz and snr=8 dB, and the estimated frequency offset is 30.05kHz.
It can be seen that the timing and frequency offset can be estimated effectively and accurately using the new sequence, and there is only one peak value, and the search is convenient. And CP is saved in the time domain, the RB number in the frequency domain can be reduced, and PRACH overhead is effectively saved under the conditions of large time delay and large frequency offset.
Corresponding to the method shown in fig. 3, the embodiment of the present invention further provides a random access channel transmission device in low-orbit satellite communication, which is used for implementing the method in fig. 3, and the random access channel transmission device in low-orbit satellite communication provided in the embodiment of the present invention may be applied to a base station, and its structural schematic diagram is shown in fig. 4, where the device includes:
an acquiring unit 401, configured to acquire time-frequency resource data;
a detecting unit 402, configured to correlate each set sequence form PN sequence in the set PN sequence set with the time-frequency resource data, so as to detect a peak value in the time-frequency resource data;
A determining unit 403, configured to determine, when a peak in the video resource data is detected, a PN sequence in the set sequence format that is currently related to the time-frequency resource data as a PN sequence transmitted by a terminal.
In the random access channel transmission device provided by the embodiment of the invention, after the time-frequency resource data sent by the terminal side is acquired at the base station side, the peak value in the time-frequency resource data is detected by acquiring the PN sequences in each set form in the set PN sequence set and carrying out a correlation mode on each acquired PN sequence, so that the PN sequence adopted by the terminal side is determined, the terminal is allowed to access the base station through the PN sequence, and the effective receiving of the signals by the base station is realized.
In the method provided by the embodiment of the present invention, referring to fig. 5, there is also provided a random access channel transmission system in low-orbit satellite communication, where the transmission system includes a terminal side and a base station side,
the terminal side comprises:
a selecting unit, configured to select a set type of PN sequence from the set PN sequence set;
a mapping unit, configured to map the PN sequence onto a subcarrier according to a preset transformation manner;
and a transmitting unit for performing Inverse Fast Fourier Transform (IFFT) on the sub-carriers mapped with the PN sequences to transform the sub-carriers mapped with the PN sequences to a time domain and transmitting the sub-carriers to a base station in a predetermined form.
The base station side includes:
the acquisition unit is used for acquiring time-frequency resource data;
the detection unit is used for respectively correlating PN sequences in the set sequence forms in the set PN sequence sets with the time-frequency resource data so as to detect peaks in the time-frequency resource data;
and the determining unit is used for determining the PN sequence in the set sequence form which is currently related to the time-frequency resource data as the PN sequence sent by the terminal when the peak value in the time-frequency resource data is detected.
The random access channel transmission system in low orbit satellite communication provided by the embodiment of the invention replaces the ZC sequence in the existing Preamble sequence with the PN sequence, thereby effectively avoiding the problem that a main peak cannot be accurately determined due to the occurrence of a pseudo peak in the transmission process. The terminal can access the base station in time, and effective transmission of signals is realized. The principle process of terminal and satellite communication in the random access channel transmission system in low-orbit satellite communication provided by the embodiment of the present invention can refer to fig. 6 provided by the embodiment of the present invention, where a very small caliber satellite communication terminal 501 communicates with a satellite-borne platform 502 through a service link, and the satellite-borne platform 502 is connected with a gateway through a feeder link.
The embodiment of the invention also provides a storage medium, which comprises a stored program, wherein when the program runs, the device where the storage medium is controlled to execute the random access channel transmission method in the low-orbit satellite communication, and the method can be specifically applied to a terminal and comprises the following steps:
the method comprises the following steps:
selecting a PN sequence in a set sequence form from the set PN sequence set;
mapping the PN sequence to subcarriers according to a preset conversion mode;
and performing Inverse Fast Fourier Transform (IFFT) on the subcarriers mapped with the PN sequences to transform the subcarriers mapped with the PN sequences to a time domain and transmitting to a base station in a predetermined form.
In the above method, optionally, if the sequence form of the PN sequence is a frequency domain PN sequence;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
the frequency domain PN sequence is directly mapped to the subcarrier.
In the above method, optionally, if the sequence form of the PN sequence is a discrete fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM modulated PN sequence;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
Performing fast fourier transform on the DFT-s-OFDM modulated PN sequence to transform the DFT-s-OFDM modulated PN sequence to a frequency domain;
mapping the PN sequence of the DFT-s-OFDM modulation transformed to the frequency domain onto the subcarrier.
In the above method, optionally, if the sequence form of the PN sequence is a frequency domain PN sequence associated with a walsh orthogonal code;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
and directly mapping the frequency domain PN sequence associated with the walsh orthogonal code onto the subcarriers.
In the above method, optionally, if the sequence form of the PN sequence is a discrete fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM modulated PN sequence associated with a walsh orthogonal code;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
performing fast fourier transform on the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to transform the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to a frequency domain;
mapping the PN sequence of the DFT-s-OFDM modulation which is transformed to the frequency domain and is associated with the walsh orthogonal code onto the subcarriers.
The above method, optionally, after transforming the DFT-s-OFDM modulated PN sequence into the frequency domain, before mapping the DFT-s-OFDM modulated PN sequence transformed into the frequency domain onto the subcarrier, further includes:
and windowing the PN sequence modulated by DFT-s-OFDM converted to the frequency domain.
The above method, optionally, after transforming the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to the frequency domain, before mapping the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code transformed to the frequency domain onto the subcarriers, further includes:
windowing is performed on the PN sequence which is transformed to the frequency domain and is modulated by DFT-s-OFDM and is associated with the Walsh orthogonal code.
The method, optionally, the transmitting to the base station in a predetermined form includes:
the PN sequence converted to the time domain is transmitted to the base station in the form that the PN sequence is provided with ZP before and GT after, the ZP is a null field, and the length of the ZP is 1-2 times of the length of the CP of the OFDM symbol of the data area.
The method, when applied to a base station, may include:
acquiring time-frequency resource data;
respectively correlating PN sequences in the form of each set sequence in the set PN sequences with the time-frequency resource data so as to detect peaks in the time-frequency resource data;
And when the peak value in the time-frequency resource data is detected, determining the PN sequence in the set sequence form which is currently related to the time-frequency resource data as the PN sequence sent by the terminal.
In the above method, optionally, the correlating the PN sequences in the set sequence form of each set PN sequence set with the time-frequency resource data includes:
dividing PN sequences in the set sequence form in the set PN sequence set into a plurality of PN sequence subsections;
and respectively correlating each PN sequence sub-segment of the PN sequence in the form of each set sequence with the time domain resource data, wherein the correlation comprises a time domain sliding correlation and a frequency domain correlation.
The embodiment of the present invention further provides an electronic device, whose structural schematic diagram is shown in fig. 7, specifically including a memory 601, and one or more programs 602, where the one or more programs 602 are stored in the memory 601, and configured to be executed by the one or more processors 603, the one or more programs 602 include instructions for:
selecting a PN sequence in a set sequence form from the set PN sequence set;
Mapping the PN sequence to subcarriers according to a preset conversion mode;
and performing Inverse Fast Fourier Transform (IFFT) on the subcarriers mapped with the PN sequences to transform the subcarriers mapped with the PN sequences to a time domain and transmitting to a base station in a predetermined form.
It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described as different from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other. For the apparatus class embodiments, the description is relatively simple as it is substantially similar to the method embodiments, and reference is made to the description of the method embodiments for relevant points.
Finally, it is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.
For convenience of description, the above devices are described as being functionally divided into various units, respectively. Of course, the functions of each element may be implemented in the same piece or pieces of software and/or hardware when implementing the present invention.
From the above description of embodiments, it will be apparent to those skilled in the art that the present invention may be implemented in software plus a necessary general hardware platform. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the embodiments or some parts of the embodiments of the present invention.
The above description is made in detail of a method and apparatus for transmitting a random access channel in low-orbit satellite communication, and specific examples are applied to illustrate the principles and embodiments of the present invention, and the above description of the embodiments is only for helping to understand the method and core ideas of the present invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.

Claims (10)

1. A method for random access channel transmission in low-orbit satellite communication, the method being applied to a terminal, the method comprising:
selecting a PN sequence in a set sequence form from the set PN sequence set;
mapping the PN sequence to subcarriers according to a preset conversion mode;
if the PN sequence is in the form of a frequency domain PN sequence associated with a walsh orthogonal code; the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps: directly mapping the frequency domain PN sequence associated with the walsh orthogonal code to the subcarrier;
performing inverse fast fourier transform IFFT on the sub-carriers mapped with the PN sequences to transform the sub-carriers mapped with the PN sequences to a time domain and transmit to a base station in a predetermined form; the transmitting to the base station in a predetermined form comprises: and transmitting the PN sequence converted to the time domain to a base station in the form of a ZP before the PN sequence and a GT after the PN sequence, wherein the ZP is a null field, and the length of the ZP is 1-2 times of the CP length of an OFDM symbol of a data area.
2. The method of claim 1, wherein if the sequence form of the PN sequence is a frequency domain PN sequence;
The mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
the frequency domain PN sequence is directly mapped to the subcarrier.
3. The method of claim 1, wherein if the sequence form of the PN sequence is a discrete fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM modulated PN sequence;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
performing fast fourier transform on the DFT-s-OFDM modulated PN sequence to transform the DFT-s-OFDM modulated PN sequence to a frequency domain;
mapping the PN sequence of the DFT-s-OFDM modulation transformed to the frequency domain onto the subcarrier.
4. The method of claim 1, wherein if the sequence form of the PN sequence is a discrete fourier transform spread orthogonal frequency division multiplexing DFT-s-OFDM modulated PN sequence associated with a walsh orthogonal code;
the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps:
performing fast fourier transform on the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to transform the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to a frequency domain;
Mapping the PN sequence of the DFT-s-OFDM modulation which is transformed to the frequency domain and is associated with the walsh orthogonal code onto the subcarriers.
5. The method of claim 3, further comprising, after transforming the DFT-s-OFDM modulated PN sequence to the frequency domain, before mapping the DFT-s-OFDM modulated PN sequence transformed to the frequency domain onto the subcarriers:
and windowing the PN sequence modulated by DFT-s-OFDM converted to the frequency domain.
6. The method of claim 4, wherein after transforming the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code to the frequency domain, before mapping the DFT-s-OFDM modulated PN sequence associated with the walsh orthogonal code transformed to the frequency domain onto the subcarriers, further comprising:
windowing is performed on the PN sequence which is transformed to the frequency domain and is modulated by DFT-s-OFDM and is associated with the Walsh orthogonal code.
7. A random access channel transmission apparatus in low-orbit satellite communication, the apparatus being applied to a terminal, the apparatus comprising:
a selecting unit, configured to select a set type of PN sequence from the set PN sequence set;
A mapping unit, configured to map the PN sequence onto a subcarrier according to a preset transformation manner; if the PN sequence is in the form of a frequency domain PN sequence associated with a walsh orthogonal code; the mapping the PN sequence to the sub-carrier according to a preset transformation mode comprises the following steps: directly mapping the frequency domain PN sequence associated with the walsh orthogonal code to the subcarrier;
a transmitting unit for performing Inverse Fast Fourier Transform (IFFT) on the sub-carriers mapped with the PN sequences to transform the sub-carriers mapped with the PN sequences to a time domain and transmitting the sub-carriers to a base station in a predetermined form; the transmitting to the base station in a predetermined form comprises: and transmitting the PN sequence converted to the time domain to a base station in the form of a ZP before the PN sequence and a GT after the PN sequence, wherein the ZP is a null field, and the length of the ZP is 1-2 times of the CP length of an OFDM symbol of a data area.
8. A method for random access channel transmission in low-orbit satellite communication, the method being applied to a base station, the method comprising:
acquiring time-frequency resource data;
respectively correlating PN sequences in the form of each set sequence in the set PN sequences with the time-frequency resource data so as to detect peaks in the time-frequency resource data;
When the peak value in the time-frequency resource data is detected, determining the PN sequence in the set sequence form which is related with the time-frequency resource data currently as the PN sequence sent by the terminal; the PN sequence sent by the terminal is provided with a ZP before, and the PN sequence sent by the terminal is provided with a GT after; the ZP is a null field, and the length of the ZP is 1-2 times of the CP length of the OFDM symbol of the data area.
9. The method of claim 8 wherein said correlating each set of PN sequences in the set of PN sequences with said time-frequency resource data comprises:
dividing PN sequences in the set sequence form in the set PN sequence set into a plurality of PN sequence subsections;
and respectively correlating each PN sequence sub-segment of the PN sequence in the form of each set sequence with the time-frequency resource data, wherein the correlation comprises a time domain sliding correlation and a frequency domain correlation.
10. A random access channel transmission device in low-orbit satellite communication, the device being applied to a base station and comprising:
the acquisition unit is used for acquiring time-frequency resource data;
the detection unit is used for respectively correlating PN sequences in the set sequence forms in the set PN sequence sets with the time-frequency resource data so as to detect peaks in the time-frequency resource data;
A determining unit, configured to determine, when a peak value in the time-frequency resource data is detected, a PN sequence in the set sequence format that is currently related to the time-frequency resource data as a PN sequence transmitted by a terminal; the PN sequence sent by the terminal is provided with a ZP before, and the PN sequence sent by the terminal is provided with a GT after; the ZP is a null field, and the length of the ZP is 1-2 times of the CP length of the OFDM symbol of the data area.
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Publication number Priority date Publication date Assignee Title
CN112888047B (en) * 2021-04-29 2021-08-06 成都星联芯通科技有限公司 PRACH signal processing method, device, communication equipment and storage medium
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WO2023108656A1 (en) * 2021-12-17 2023-06-22 北京小米移动软件有限公司 Measurement method and apparatus for global navigation satellite system (gnss)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101473585A (en) * 2006-06-13 2009-07-01 高通股份有限公司 Reverse link pilot transmission for a wireless communication system
CN101496368A (en) * 2006-07-28 2009-07-29 高通股份有限公司 Method and apparatus for sending signaling for data transmission in a wireless communication system
CN102548018A (en) * 2011-03-25 2012-07-04 北京新岸线无线技术有限公司 Wireless communication system and communication method thereof
CN102696193A (en) * 2010-01-07 2012-09-26 Lg电子株式会社 Method and apparatus for generating a reference signal sequence in a wireless communication system
CN106961408A (en) * 2016-01-11 2017-07-18 中兴通讯股份有限公司 A kind of uplink signal sending method and device
CN107248968A (en) * 2015-01-30 2017-10-13 上海数字电视国家工程研究中心有限公司 The generation method of leading symbol
CN108282322A (en) * 2017-01-06 2018-07-13 华为技术有限公司 A kind of method and apparatus of configuration reference signal
CN108631968A (en) * 2017-03-20 2018-10-09 华为技术有限公司 A kind of determination method and device of data feedback resource
CN108886448A (en) * 2016-03-27 2018-11-23 Lg 电子株式会社 The method and device thereof of around uplink demodulation reference signal are sent and received in wireless communication system

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101273293B1 (en) * 2009-04-27 2013-06-11 후아웨이 테크놀러지 컴퍼니 리미티드 Positioning reference signals
JP2019527972A (en) * 2016-07-29 2019-10-03 華為技術有限公司Ｈｕａｗｅｉ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｏ．，Ｌｔｄ． Inter-device communication method and user equipment

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101473585A (en) * 2006-06-13 2009-07-01 高通股份有限公司 Reverse link pilot transmission for a wireless communication system
CN101496368A (en) * 2006-07-28 2009-07-29 高通股份有限公司 Method and apparatus for sending signaling for data transmission in a wireless communication system
CN102696193A (en) * 2010-01-07 2012-09-26 Lg电子株式会社 Method and apparatus for generating a reference signal sequence in a wireless communication system
CN102548018A (en) * 2011-03-25 2012-07-04 北京新岸线无线技术有限公司 Wireless communication system and communication method thereof
CN107248968A (en) * 2015-01-30 2017-10-13 上海数字电视国家工程研究中心有限公司 The generation method of leading symbol
CN106961408A (en) * 2016-01-11 2017-07-18 中兴通讯股份有限公司 A kind of uplink signal sending method and device
CN108886448A (en) * 2016-03-27 2018-11-23 Lg 电子株式会社 The method and device thereof of around uplink demodulation reference signal are sent and received in wireless communication system
CN108282322A (en) * 2017-01-06 2018-07-13 华为技术有限公司 A kind of method and apparatus of configuration reference signal
CN108631968A (en) * 2017-03-20 2018-10-09 华为技术有限公司 A kind of determination method and device of data feedback resource

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Denomination of invention: Random Access Channel Transmission Methods and Devices in Low Earth Orbit Satellite Communications

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