Synchronous channel design method based on 5G waveform

Abstract

The invention discloses a 5G waveform-based synchronous channel design method. The method comprises the following steps of: dividing a system working bandwidth into a plurality of sub-bands; determining a candidate frequency domain position of a synchronization channel in each sub-band, wherein the synchronization channel is composed of a PSS and an SSS; and determining values of the PSS sequence and the SSS sequence according to the indexes corresponding to the PSS sequence and the SSS sequence, determining one or more frequency domain positions from the candidate frequency domain positions, and filling the selected frequency domain positions with the PSS sequence and the SSS sequence. In different interference and fading scenes, the time-frequency position of the synchronization channel can be adaptively selected according to interference and fading, so that the frequency domain position of interference and fading is avoided, and better performance is obtained.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a synchronization channel design method based on 5G waveform, which is particularly suitable for mobile deployment scenarios with time-varying interference. Background Art

[0002] In the field of wireless communication applications, overcoming the impact of wireless channels is one of the most critical issues in wireless communication technology. Interference and fading in wireless channels are two key factors affecting wireless communication performance. They can significantly impact signal transmission quality, communication reliability, and system capacity, leading to problems such as increased bit error rates, degraded signal quality, communication interruptions, reduced spectrum efficiency, a degraded user experience, limited coverage, and reduced system performance.

[0003] The 5G-NR waveform system and its evolved waveform system support a wide frequency range from low-band to millimeter-wave bands, and its operating bandwidth is relatively wide. For the SUB6 band, it can support an operating bandwidth of up to 100 MHz. Therefore, the impact of interference and fading on the system is very significant.

[0004] In the standard waveform system definition of 5G-NR, the definition of the synchronization channel (SS / PBCH channel) cannot effectively cope with the impact of interference and fading, especially time-varying interference and fading, whether for fixed base station deployment scenarios (i.e., the base station site planning is fixed and unchanged after completion) or for mobile base station deployment scenarios (i.e., the base station site planning is uncertain), especially for special application scenarios and emergency communication scenarios. It is basically not allowed to reselect the time-frequency position of the synchronization channel during the entire working time after cell activation to cope with different interference and fading. Reselecting the time-frequency position is very costly. Summary of the Invention

[0005] In order to address the impact of time-varying interference and fading on the system in the 5G-NR standard waveform system, in the evolved waveform system based on 5G-NR, the present application provides a synchronization channel design method based on the 5G waveform, and designs a new type of synchronization channel to cope with time-varying interference and fading.

[0006] This application discloses a synchronization channel design method based on 5G waveform, which includes:

[0007] Divide the system working bandwidth into several sub-bands;

[0008] Determine a candidate frequency domain location of a synchronization channel in each subband, wherein the synchronization channel is composed of a PSS and an SSS;

[0009] According to the indexes corresponding to the PSS sequence and the SSS sequence, the values of the PSS sequence and the SSS sequence are determined, and one or more frequency domain positions are determined from the candidate frequency domain positions, and the PSS sequence and the SSS sequence are filled into the selected frequency domain positions.

[0010] Furthermore, the frequency domain position candidate set of the synchronization channel, that is, determining the candidate frequency domain position of the synchronization channel in each subband, includes:

[0011] In each subband on two symbols of a specified time slot, the candidate frequency domain positions of the PSS and SSS in the synchronization channel are predefined, that is, for all subbands in each symbol of the symbol, there is a continuous frequency domain position in each subband and it is defined as a frequency domain resource grid, and all resource elements in the frequency domain resource grid are used only to map the PSS sequence and the SSS sequence; wherein, the candidate frequency domain positions of the PSS and SSS respectively correspond to one symbol in the time domain; and the symbols corresponding to the candidate frequency domain positions of the PSS and SSS are different;

[0012] By determining the frequency domain starting position of the PSS sequence and SSS sequence in the frequency domain resource grid in each subband, the candidate frequency domain positions of the PSS sequence and SSS sequence in each subband can be determined. The candidate frequency domain positions of the PSS and SSS in all subbands constitute the frequency domain position candidate set of the synchronization channel.

[0013] Furthermore, the PSS is a signal obtained by mapping a ZC sequence of length 127 in a frequency domain resource grid, and the SSS is a signal obtained by mapping a ZC sequence of length 127 in a frequency domain resource grid;

[0014] The resource units occupied by the mapping positions of the PSS sequence and the SSS sequence on the frequency domain resource grid have the same index, both occupy 127 resource units, and the 127 resource units are continuous frequency domain resource units;

[0015] The 127 resource units occupied by the PSS sequence and the SSS sequence only occupy the middle 127 consecutive resource units in 11 or 12 resource blocks, and the resource units on both sides are not occupied; each of the resource blocks consists of 12 resource units.

[0016] Furthermore, determining the frequency domain center positions of the PSS sequence and the SSS sequence in the system operating frequency band, that is, determining from a frequency domain position candidate set, includes:

[0017] According to the starting frequency position of the system operating frequency band and the system operating bandwidth, the primary frequency domain resource grid of the PSS sequence and SSS sequence in each corresponding sub-band is calculated, and then the center frequency of the primary frequency domain resource grid occupied by the PSS sequence and SSS sequence is calculated;

[0018] Calculate the center frequencies of the frequency domain resource grids occupied by the final-selected PSS and SSS sequences according to the center frequencies of the pre-selected frequency domain resource grids of the PSS and SSS sequences in each subband;

[0019] Calculate the frequency difference between the center frequency of the frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band;

[0020] According to the frequency difference, calculate the starting frequency N of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence CRB and K SS ; By parameter N CRB and K SS Determines the frequency domain starting position of the PSS sequence and SSS sequence in the time-frequency resource grid.

[0021] Furthermore, the method calculates the preliminary selected frequency domain resource grid of the PSS sequence and the SSS sequence in each corresponding subband according to the center frequency position of the system operating frequency band and the system operating bandwidth, and then calculates the center frequency of the frequency domain resource grid occupied by the preliminary selected PSS sequence and the SSS sequence, including:

[0022] Determine the starting frequency value F of the system operating frequency band point-A , F point-A Preselected frequency F according to frequency planning sel For calculation, the center frequency of the frequency domain resource grid occupied by the PSS sequence and the SSS sequence is selected as the center frequency of each sub-band as much as possible, F point-A The expression is:

[0023]

[0024] Among them, F sel is the starting frequency of the initially selected working frequency band, The minimum usable frequency within the operating frequency band;

[0025] Calculate the center frequency F' of the primary frequency domain resource grid occupied by the PSS sequence and SSS sequence SS , define the number of subbands as K, F' SS The expression is:

[0026] When the operating bandwidth is greater than 20MHz, then:

[0027]

[0028] When the operating bandwidth is 20MHz, then:

[0029] If it is divided into 2 sections, that is, K = 2, then: F' SS =F point-A+9.6*(i-1)+4.8,&i≥0and i≤K;

[0030] If it is divided into 1 segment, that is, K = 1, then: F' SS =F point-A +9.6

[0031] Where i represents the i-th subband, and K represents the maximum number of subbands in the system operating bandwidth.

[0032] Furthermore, the calculating of the center frequencies of the frequency domain resource grids occupied by the finally selected PSS sequences and SSS sequences according to the center frequencies of the preliminarily selected frequency domain resource grids of the PSS sequences and SSS sequences includes:

[0033] According to the frequency starting point, a reference frequency set is calculated and the reference frequency set is combined with F′ SS The reference frequency FREF with the smallest difference is used as the center frequency F of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence SS ; The reference frequency set is composed of reference frequencies; the calculation formula of the reference frequency is:

[0034] FREF=FREF Offs +ΔFGlobal*(NREF–NREF Offs )

[0035] Among them, FREF is the reference frequency, FREF Offs is the frequency starting point, ΔFGlobal is the global grid granularity, NREF is the frequency point number, NREF Offs is the starting point of the frequency point, and its corresponding value is:

[0036] When the reference frequency FREF ranges from 0 to 3000kHz, ΔFGlobal is 5kHz, and FREF Offs 0MHz, NREF Offs 0MHz, NREF value is 0-599999, and the step size of NREF value is 432;

[0037] When the reference frequency FREF ranges from 3000 to 24250kHz, ΔFGlobal is 15kHz, FREF Offs 3000MHz, NREF Offs The frequency band is 600000 MHz, the NREF value is 600000-2016666, and the step size of the NREF value is 144.

[0038] Furthermore, the calculating of the frequency difference between the center frequency of the frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band includes:

[0039] The frequency difference between the center frequency of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band is obtained by the following formula:

[0040] Δf=(F SS -(F point-A )

[0041] Wherein, Δf is the frequency difference between the center frequency of the frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band;

[0042] The frequency domain resource grid starting frequency N of the final selected PSS sequence and SSS sequence is calculated based on the frequency difference. CRB and K SS ,include:

[0043] K is obtained using the following formula SS :

[0044]

[0045] Use the following formula to get N CRB :

[0046]

[0047] Furthermore, determining the values of the PSS sequence and the SSS sequence according to the indexes corresponding to the PSS sequence and the SSS sequence, determining one or more frequency domain positions from the candidate frequency domain positions, and filling the PSS sequence and the SSS sequence into the selected frequency domain positions includes:

[0048] The system defines multiple PSS sequences and SSS sequences. Each PSS sequence and SSS sequence is indexed by a sequence ID, and the corresponding sequence IDs are PSS_id and SSS_id.

[0049] According to the correspondence between the PNID value and each PSS sequence and SSS sequence, the index of the PSS sequence and SSS sequence corresponding to each PNID is obtained;

[0050] According to the index of the PSS sequence and the SSS sequence, the PSS sequence and the SSS sequence corresponding to the index are filled into the candidate frequency domain resource grids of the PSS sequence and the SSS sequence in each subband corresponding to the system working frequency band.

[0051] Furthermore, the PSS sequence and SSS sequence are generated using the ZC sequence;

[0052] In the time domain, the PSS sequence only occupies the second symbol, the SSS sequence only occupies the fourth symbol, and the symbol index starts counting from 0;

[0053] When multiple synchronization channels are supported in a single time slot, the PSS and SSS in each synchronization channel may use the same or different ZC sequences as the PSS and SSS in other synchronization channels.

[0054] The system supports multiple PSS and SSS sequences. The number of PSS sequences is defined as 3, and the number of SSS sequences is defined as 11.

[0055] Furthermore, under different working bandwidths, the system transmits synchronization signals only at candidate frequency domain positions in each sub-band; the synchronization channel is defined on the synchronization grid, that is, the first resource unit occupied by the synchronization channel is an integer multiple of 15KHz.

[0056] Due to the adoption of the above technical solution, this application has the following advantages:

[0057] In different interference and fading scenarios, the present application can adaptively select the time-frequency position of the synchronization channel according to interference and fading (including time-varying interference and fading) to avoid the frequency domain position of interference and fading, thereby obtaining better performance; specifically, in different interference and fading scenarios (especially time-varying interference and fading scenarios), it can dynamically detect the frequency domain position with the lowest interference or fading within the working bandwidth, and execute the corresponding frequency selection scheduling strategy to send the synchronization channel at the optimal frequency domain position. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0059] Figure 1 Schematic diagram of candidate frequency domain positions of PSS (primary synchronization signal) and SSS (secondary synchronization signal) according to an embodiment of the present application;

[0060] Figure 2 Schematic diagram of the distribution of REs (resource units) corresponding to the PSS and SSS channels in an embodiment of the present application;

[0061] Figure 3 Schematic diagram of frequency domain resource calculation and processing of PSS and SSS in an embodiment of the present application;

[0062] Figure 4 Schematic diagram of PSS and SSS frequency domain candidate positions in an embodiment of the present application. DETAILED DESCRIPTION

[0063] The present application is further described with reference to the accompanying drawings and embodiments. The embodiments described are only a part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present application.

[0064] This application provides an embodiment of a synchronization channel design method based on a 5G waveform, where the synchronization channel is used to transmit synchronization signals. The method supports different interference and fading scenarios (especially time-varying interference and fading scenarios), dynamically detects interference and fading information within the working bandwidth, selects optimal time-frequency domain resources based on real-time interference and fading information, and designs a synchronization channel based on the channel for transmission of synchronization signals.

[0065] See also Figure 2 The synchronization channel in this application is similar to the broadcast channel (SSB / PBCH) in the 3GPP 5G-NR standard, specifically:

[0066] Sequence definition: The synchronization channel includes the PSS (primary synchronization signal) and the SSS (secondary synchronization signal). The PSS (primary synchronization signal) is a signal obtained by mapping a ZC sequence of length 127 to specific frequency domain resources, and the SSS (secondary synchronization signal) is a signal obtained by mapping a ZC sequence of length 127 to specific frequency domain resources. The PSS and SSS sequences in the synchronization signal are both ZC sequences of length 127, which are the same as those defined in the 5G-NR standard of 3GPP.

[0067] Frequency domain position: As defined in the 3GPP 5G-NR standard, the RE (resource unit) index occupied by the mapping position of the PSS and SSS sequences on the frequency domain resources is the same, occupying 127 REs respectively, and these 127 REs are continuous REs. Since the index of the first RE occupied by PSS and SSS (counting from the low frequency to the high frequency within the working bandwidth) may not be an integer multiple of 12, according to the definition of the 3GPP 5G-NR standard, every 12 REs are an RB (resource block), then the PSS and SSS sequences will occupy 11 or 12 RBs, and the 127 REs of the PSS and SSS sequences will only occupy the middle 127 continuous REs in the 11 or 12 RBs, and the REs on both sides will not be occupied. Unlike the 3GPP 5G-NR standard definition, multiple synchronization channels are allowed in a time slot. To reduce the synchronization detection workload at the receiver, multiple candidate frequency domain locations are pre-defined for the PSS and SSS frequency domain locations under different operating bandwidths. The system only transmits synchronization signals at these pre-defined candidate frequency domain locations. Unlike the 3GPP 5G-NR standard definition, the synchronization channel is defined on the synchronization grid, that is, the first RE occupied by the synchronization channel is an integer multiple of 15 kHz.

[0068] Time domain position: The 3GPP 5G-NR standard has the same definition. In the time domain, the PSS sequence occupies one OFDM symbol, which is the second OFDM symbol (the symbol index starts counting from 0), and the SSS sequence occupies one OFDM symbol, which is the fifth OFDM symbol (the symbol index starts counting from 0).

[0069] About sub-band division:

[0070] First, define the subband. The system's operating bandwidth consists of multiple subbands. The number of subbands varies under different operating bandwidths, and the bandwidth of each subband may not be the same. All subbands share the operating bandwidth almost evenly, as shown in Table 1.

[0071] Table 1 Segments under different working bandwidths

[0072]

[0073] Regarding the candidate set of frequency resources occupied by PSS and SSS sequences:

[0074] Similar to the 5G-NR standard definition of 3GPP, this application defines time-frequency resources as time-frequency resource grids. The number of resource units in a time-frequency resource grid within a time slot is 273*14, that is, 3822 time-frequency resource grids.

[0075] For different working bandwidths, each subband has certain specific time-frequency resource grids for mapping PSS and SSS sequences. For working bandwidths of 20MHz to 100MHz, the PSS and SSS sequences occupy candidate time-frequency resource grids such as Figure 1 shown.

[0076] A single time slot supports multiple synchronization channels simultaneously. When multiple synchronization channels are supported in a single time slot, the PSS and SSS in each synchronization channel can use the same or different ZC sequence as the PSS and SSS in other synchronization channels.

[0077] The synchronization search grid size of the synchronization channel is 1.2 MHz, or a multiple of 1.2 MHz.

[0078] For the selection of PSS and SSS sequences:

[0079] Similar to the 3GPP 5G-NR standard definition, the system supports multiple PSS and SSS sequences. To reduce the number of synchronization detections performed by the receiving end, the number of PSS and SSS sequences is limited. The number of PSS sequences is defined as 3, and the number of SSS sequences is defined as 11.

[0080] The figure below shows a new synchronization channel design scheme based on the synchronization channel evolution in the 5G standard waveform in this application example. Among them, PSS and SSS are synchronization channels, PCCH DATA and PCCH DMRS are control channels, and PSCH DATA and PSCH DMRS are data channels.

[0081] like Figure 2 As shown, the left figure is the time-frequency resource grid of the synchronization channel (PSS and SSS) when the PCCH (control channel) occupies 1 OFDM symbol, and the right figure is the time-frequency resource grid of the synchronization channel (PSS and SSS) when the PCCH (control channel) occupies 2 OFDM symbols. The red and brown squares in the figure are schematic diagrams of the time-frequency resource grids occupied by the PSS and SSS of the synchronization channel.

[0082] In order to reduce the computational complexity of blind synchronization, the patterns of the time-frequency domain resource grids occupied by the PSS and SSS sequences are predefined. When the working bandwidth is 100 MHz, the predefined patterns of the time-frequency domain resource grids occupied by the PSS and SSS sequences are as follows: Figure 1 As shown in the first sub-figure in .

[0083] To calculate the predefined pattern of time-frequency resource locations, first define subbands based on the system operating bandwidth, with all subbands sharing the operating bandwidth approximately evenly. Within each subband, there is a time-frequency resource grid to which the PSS and SSS sequences can be mapped. Their time-domain locations are the second and fifth OFDM symbols, respectively, and their frequency-domain locations are determined by and . The calculation method is the same as the frequency-domain location definition of the SSB in 3GPP's 5G-NR.

[0084] From the perspective of the transmitter, the calculation process of the time-frequency domain resource grid occupied by the PSS and SSS sequences is as follows: Figure 3 shown.

[0085] To facilitate understanding, this application provides a more specific embodiment from the perspective of the sender:

[0086] Step 1: Divide the system operating bandwidth into several sub-bands.

[0087] Determine the subband division of the candidate frequency domain resource grid occupied by the synchronization channels (PSS and SSS). First, divide the system's operating bandwidth into multiple subbands. The number of subbands varies for different operating bandwidths, and the bandwidth of each subband may vary. All subbands share the operating bandwidth approximately evenly. As shown in Table 2, the frequency values in the table are the starting frequencies of each subband. For operating bandwidths greater than 20 MHz, each subband is divided according to a bandwidth of approximately 20 MHz. For operating bandwidths of 20 MHz, two subband divisions are supported: one subband and two subbands.

[0088] Table 2 Segments under different working bandwidths

[0089]

[0090] Step 2: Determine the candidate frequency domain position of the synchronization channel in each subband, where the synchronization channel consists of the PSS and SSS.

[0091] Optionally, the frequency domain position candidate set of the synchronization channel, that is, determining the candidate frequency domain position of the synchronization channel in each subband, includes:

[0092] In each subband on two symbols of a specified time slot, the candidate frequency domain positions of the PSS and SSS in the synchronization channel are predefined, that is, for all subbands in each symbol of the symbol, there is a continuous frequency domain position (defined as: frequency domain resource grid) in each subband, and all resource elements in the frequency domain resource grid are used only to map the PSS sequence and the SSS sequence; wherein, the candidate frequency domain positions of the PSS and SSS respectively correspond to one symbol in the time domain; and the symbols corresponding to the candidate frequency domain positions of the PSS and SSS are different;

[0093] By determining the frequency domain starting position of the PSS sequence and SSS sequence in the frequency domain resource grid in each subband, the candidate frequency domain positions of the PSS sequence and SSS sequence in each subband can be determined. The candidate frequency domain positions of the PSS and SSS in all subbands constitute the frequency domain position candidate set of the synchronization channel.

[0094] Specifically, for different working bandwidths, each sub-band has a candidate frequency position for PSS and SSS. Taking the working bandwidth of 100MHz as an example, the candidate frequency domain positions of PSS and SSS are as follows: Figure 4 shown.

[0095] The search grid size of the synchronization channel is 4.8MHz. In order to reduce the computational complexity of blind synchronization, the frequency domain positions of the PSS and SSS in the synchronization channel are predefined in each subband. That is, in each subband, there are certain specific time-frequency resource grids for mapping the PSS and SSS sequences. The frequency domain starting position of the time-frequency resource grid is determined by the parameter N. CRB and K SS Indicates that, N CRB is the index of the RB starting from the starting position of the working frequency band, K SSis the index of RE within an RB. The RE index occupied by the mapping position of the PSS and SSS sequences on the frequency domain resources is the same, and each occupies 127 REs, and these 127 REs are continuous REs. Since the index of the first RE occupied by PSS and SSS (counting from the low frequency to the high frequency within the working bandwidth) may not be an integer multiple of 12, referring to the definition of 3GPP's 5G-NR standard, every 12 REs are an RB, the PSS and SSS sequences occupy 11 or 12 RBs, and the 127 REs of the PSS and SSS sequences will only occupy the middle 127 continuous REs in the 11 or 12 RBs, and the REs on both sides will not be occupied.

[0096] Alternatively, see Figure 3 The determining of the frequency domain starting positions of the PSS sequence and the SSS sequence in the frequency domain resource grid in each subband, i.e., determining from a frequency domain position candidate set, includes:

[0097] According to the center frequency position of the system operating frequency band and the system operating bandwidth, the preliminary selected frequency domain resource grid of the PSS sequence and SSS sequence in each corresponding sub-band is calculated, and then the center frequency of the preliminary selected frequency domain resource grid occupied by the PSS sequence and SSS sequence is calculated;

[0098] Calculate the center frequencies of the frequency domain resource grids occupied by the final-selected PSS and SSS sequences according to the center frequencies of the pre-selected frequency domain resource grids of the PSS and SSS sequences in each subband;

[0099] Calculate the frequency difference between the center frequency of the frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band;

[0100] According to the frequency difference, calculate the starting frequency N of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence CRB and K SS ; By parameter N cRB and K SS Determines the frequency domain starting position of the PSS sequence and SSS sequence in the time-frequency resource grid.

[0101] Optionally, according to the starting frequency position of the system operating frequency band and the system operating bandwidth, the preliminary selected frequency domain resource grid of the PSS sequence and the SSS sequence in each corresponding subband is calculated, and then the center frequency of the frequency domain resource grid occupied by the preliminary selected PSS sequence and SSS sequence is calculated, including:

[0102] Determine the starting frequency value F of the system operating frequency band point-A , F point-A Preselected frequency F according to frequency planning sel(The starting frequency of the frequency band with lower interference is selected according to the actual electromagnetic interference situation) is calculated, and the center frequency of the frequency domain resource grid occupied by the PSS sequence and the SSS sequence is selected as the center frequency of each sub-band as much as possible. point-A The expression is:

[0103]

[0104] Among them, F sel The starting frequency of the pre-selected working frequency band shall not be less than 566.94 MHz. The minimum available frequency within the operating frequency band. Taking the 566MHz to 678MHz frequency band as an example, F point-A =566.94MHz, Note: All frequencies are in MHz. According to the definition of SSB frequency point and frequency in 3GPP 38 protocol, the center frequency F of the available PSS and SSS occupied frequency resource grid can be calculated as shown in Table 3. SS The candidate positions of the predetermined PSS and SSS need to be selected from this table.

[0105] Table 3 Center frequency F of the frequency domain resource grid occupied by available PSS and SSS within 566MHz to 678MHz SS and the corresponding frequency

[0106]

[0107]

[0108] Calculate the center frequency F′ of the frequency domain resource grid occupied by the PSS sequence and SSS sequence SS , define the number of subbands as K, F′ SS The expression is:

[0109] When the operating bandwidth is greater than 20MHz, then:

[0110]

[0111] When the operating bandwidth is 20MHz, then:

[0112] If it is divided into 2 sections, that is, K = 2, then: F' SS =F point-A +9.6*(i-1)+4.8,

[0113] &i≥0and i≤K

[0114] If it is divided into 1 segment, that is, K = 1, then: F' SS =F point-A +9.6

[0115] In the above formula, i represents the i-th subband, and K represents the maximum number of subbands in the system operating bandwidth.

[0116] Optionally, the calculating, based on the center frequencies of the pre-selected frequency domain resource grids of the PSS sequence and the SSS sequence in each subband, the center frequencies of the frequency domain resource grids occupied by the final-selected PSS sequence and the SSS sequence includes:

[0117] According to the frequency starting point, a reference frequency set is calculated and the reference frequency set is combined with F′ SS The reference frequency FREF with the smallest difference is used as the center frequency F of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence SS ; The reference frequency set is composed of reference frequencies; the calculation formula of the reference frequency is:

[0118] FREF=FREF Offs +ΔFGlobal*(NREF–NREF Offs )

[0119] Among them, FREF is the reference frequency, FREF Offs is the frequency starting point, ΔFGlobal is the global grid granularity, NREF is the frequency point number, NREF Offs is the starting point of the frequency point, and its corresponding value is:

[0120] When the reference frequency FREF ranges from 0 to 3000kHz, ΔFGlobal is 5kHz, and FREF Offs 0MHz, NREF Offs When the reference frequency FREF is in the range of 3000 to 24250kHz, ΔFGlobal is 15kHz, and FREF is 0MHz. Offs 3000MHz, NREF Offs The frequency band is 600000 MHz, the NREF value ranges from 600000 to 2016666, and the step size of the NREF value is 144, as shown in Table 4.

[0121] Table 4 Mapping relationship between frequency parameters and frequency

[0122]

[0123] Optionally, the calculating a frequency difference between a center frequency of a frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and a start frequency of a working frequency band includes:

[0124] The frequency difference between the center frequency of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band is obtained by the following formula:

[0125] Δf=(F SS -(F point-A )

[0126] Wherein, Δf is the frequency difference between the center frequency of the frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and the starting frequency of the working frequency band;

[0127] The frequency domain resource grid starting frequency N of the final selected PSS sequence and SSS sequence is calculated based on the frequency difference. CRB and K SS ,include:

[0128] K is obtained using the following formula SS :

[0129]

[0130] Use the following formula to get N CRB :

[0131]

[0132] Step 3: Determine the values of the PSS sequence and the SSS sequence according to the indexes corresponding to the PSS sequence and the SSS sequence, and determine one or more frequency domain positions from the candidate frequency domain positions, and fill the PSS sequence and the SSS sequence into the selected frequency domain positions.

[0133] Optionally, determining the values of the PSS sequence and the SSS sequence according to the indexes corresponding to the PSS sequence and the SSS sequence, determining one or more frequency domain positions from the candidate frequency domain positions, and filling the PSS sequence and the SSS sequence into the selected frequency domain positions includes:

[0134] The system defines multiple PSS sequences and SSS sequences. Each PSS sequence and SSS sequence is indexed by a sequence ID, and the corresponding sequence IDs are PSS_id and SSS_id.

[0135] According to the correspondence between the PNID value and each PSS sequence and SSS sequence, the index of the PSS sequence and SSS sequence corresponding to each PNID is obtained;

[0136] According to the index of the PSS sequence and the SSS sequence, the PSS sequence and the SSS sequence corresponding to the index are filled into the candidate frequency domain resource grids of the PSS sequence and the SSS sequence in each subband corresponding to the system working frequency band.

[0137] Specifically, the PSS and SSS sequences are defined as follows: There are multiple system-defined PSS and SSS sequences, each indexed by a specific sequence ID, PSS_id and SSS_id, as shown in Table 5. The PNID is calculated based on the PSS_id and SSS_id. Specifically, PNID = (3 × SSS_id) + PSS_id. The PNID value ranges from 0 to 1007, corresponding to 0x000 to 0x3EF in hexadecimal. The number of bits is 10.

[0138] For a given PNID, by looking up Table 5 below, the sequence IDs of PSS and SSS can be obtained, and the PSS sequence and SSS sequence can be determined.

[0139] Table 5 Relationship between PNID values and PSS and SSS sequences

[0140]

[0141]

[0142] In different signal interference and fading scenarios, this application can adaptively select the time-frequency position of the synchronization channel according to interference and fading (including time-varying interference and fading) to avoid the frequency domain position of interference and fading, thereby obtaining better performance.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present application should be included in the scope of protection of the claims of the present application.

Claims

1. A synchronization channel design method based on 5G waveform, characterized in that: include: Divide the system working bandwidth into several sub-bands; Determine a candidate frequency domain location of a synchronization channel in each subband, wherein the synchronization channel is composed of a PSS and an SSS; According to the indexes corresponding to the PSS sequence and the SSS sequence, the values of the PSS sequence and the SSS sequence are determined, and one or more frequency domain positions are determined from the candidate frequency domain positions, and the PSS sequence and the SSS sequence are filled into the selected frequency domain positions.

2. The method according to claim 1, characterized in that The frequency domain position candidate set of the synchronization channel, i.e., determining the candidate frequency domain position of the synchronization channel in each sub-band, includes: In each subband on two symbols of a specified time slot, the candidate frequency domain positions of the PSS and SSS in the synchronization channel are predefined, that is, for all subbands in each symbol of the symbol, there is a continuous frequency domain position in each subband and it is defined as a frequency domain resource grid, and all resource elements in the frequency domain resource grid are used only to map the PSS sequence and the SSS sequence; wherein, the candidate frequency domain positions of the PSS and SSS respectively correspond to one symbol in the time domain; and the symbols corresponding to the candidate frequency domain positions of the PSS and SSS are different; By determining the frequency domain starting position of the PSS sequence and SSS sequence in the frequency domain resource grid in each subband, the candidate frequency domain positions of the PSS sequence and SSS sequence in each subband can be determined. The candidate frequency domain positions of the PSS and SSS in all subbands constitute the frequency domain position candidate set of the synchronization channel.

3. The method according to claim 2, characterized in that PSS is the signal obtained by mapping a ZC sequence of length 127 in the frequency domain resource grid, and SSS is the signal obtained by mapping a ZC sequence of length 127 in the frequency domain resource grid; The resource units occupied by the mapping positions of the PSS sequence and the SSS sequence on the frequency domain resource grid have the same index, both occupy 127 resource units, and the 127 resource units are continuous frequency domain resource units; The 127 resource units occupied by the PSS sequence and the SSS sequence only occupy the middle 127 consecutive resource units in 11 or 12 resource blocks, and the resource units on both sides are not occupied; each of the resource blocks consists of 12 resource units.

4. The method according to claim 2, characterized in that The determining of the frequency domain center positions of the PSS sequence and the SSS sequence in the system operating frequency band, i.e., determining from a frequency domain position candidate set, includes: According to the starting frequency position of the system operating frequency band and the system operating bandwidth, the primary frequency domain resource grid of the PSS sequence and SSS sequence in each corresponding sub-band is calculated, and then the center frequency of the primary frequency domain resource grid occupied by the PSS sequence and SSS sequence is calculated; Calculate the center frequencies of the frequency domain resource grids occupied by the final-selected PSS and SSS sequences according to the center frequencies of the pre-selected frequency domain resource grids of the PSS and SSS sequences in each subband; Calculate the frequency difference between the center frequency of the frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band; According to the frequency difference, calculate the starting frequency N of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence CRB and K SS ; By parameter N CRB and K SS Determines the frequency domain starting position of the PSS sequence and SSS sequence in the time-frequency resource grid.

5. The method according to claim 4, characterized in that The method of calculating the preliminary selected frequency domain resource grid of the PSS sequence and the SSS sequence in each corresponding sub-band according to the center frequency position of the system operating frequency band and the system operating bandwidth, and then calculating the center frequency of the frequency domain resource grid occupied by the preliminary selected PSS sequence and the SSS sequence, includes: Determine the starting frequency value F of the system operating frequency band point-A , F point-A Preselected frequency F according to frequency planning sel For calculation, the center frequency of the frequency domain resource grid occupied by the PSS sequence and the SSS sequence is selected as the center frequency of each sub-band as much as possible, F point-A The expression is: Among them, F sel is the starting frequency of the initially selected working frequency band, The minimum usable frequency within the operating frequency band; Calculate the center frequency F' of the primary frequency domain resource grid occupied by the PSS sequence and SSS sequence SS , define the number of subbands as K, F' SS The expression is: When the operating bandwidth is greater than 20MHz, then: When the operating bandwidth is 20MHz, then: If it is divided into 2 sections, that is, K = 2, then: F' SS =F point-A +9.6*(i-1)+4.8,&i≥0and i≤K; If it is divided into 1 segment, that is, K=1, then: F' SS =F point-A +9.6 Where i represents the i-th subband, and K represents the maximum number of subbands in the system operating bandwidth.

6. The method according to claim 5, characterized in that The calculating, based on the center frequencies of the preliminarily selected frequency domain resource grids of the PSS sequence and the SSS sequence, the center frequencies of the frequency domain resource grids occupied by the finally selected PSS sequence and the SSS sequence includes: According to the frequency starting point, a reference frequency set is calculated and the reference frequency set is combined with F' SS The reference frequency FREF with the smallest difference is used as the center frequency F of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence SS ; The reference frequency set is composed of reference frequencies; the calculation formula of the reference frequency is: FREF=FREF Offs +ΔFGlobal*(NREF–NREF Offs ) Among them, FREF is the reference frequency, FREF Offs is the frequency starting point, ΔFGlobal is the global grid granularity, NREF is the frequency point number, NREF Offs is the starting point of the frequency point, and its corresponding value is: When the reference frequency FREF ranges from 0 to 3000kHz, ΔFGlobal is 5kHz, and FREF Offs 0MHz, NREF Offs 0MHz, NREF value is 0-599999, and the step size of NREF value is 432; When the reference frequency FREF ranges from 3000 to 24250kHz, ΔFGlobal is 15kHz, FREF Offs 3000MHz, NREF Offs The frequency band is 600000 MHz, the NREF value is 600000-2016666, and the step size of the NREF value is 144.

7. The method according to claim 6, characterized in that The calculating of the frequency difference between the center frequency of the frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band includes: The frequency difference between the center frequency of the frequency domain resource grid occupied by the final selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band is obtained by the following formula: Δf=(F SS -(F point-A ) Wherein, Δf is the frequency difference between the center frequency of the frequency domain resource grid occupied by the finally selected PSS sequence and SSS sequence and the starting frequency of the system operating frequency band; The frequency domain resource grid starting frequency N of the final selected PSS sequence and SSS sequence is calculated based on the frequency difference. CRB and K SS ,include: K is obtained using the following formula SS : Use the following formula to get N CRB :

8. The method according to claim 1, characterized in that The determining, according to the indexes corresponding to the PSS sequence and the SSS sequence, the values of the PSS sequence and the SSS sequence, determining one or more frequency domain positions from the candidate frequency domain positions, and filling the PSS sequence and the SSS sequence into the selected frequency domain positions, includes: The system defines multiple PSS sequences and SSS sequences. Each PSS sequence and SSS sequence is indexed by a sequence ID, and the corresponding sequence IDs are PSS_id and SSS_id. According to the correspondence between the PNID value and each PSS sequence and SSS sequence, the index of the PSS sequence and SSS sequence corresponding to each PNID is obtained; According to the index of the PSS sequence and the SSS sequence, the PSS sequence and the SSS sequence corresponding to the index are filled into the candidate frequency domain resource grids of the PSS sequence and the SSS sequence in each subband corresponding to the system working frequency band.

9. The method according to claim 1, characterized in that PSS sequence and SSS sequence are generated using ZC sequence; In the time domain, the PSS sequence only occupies the second symbol, the SSS sequence only occupies the fourth symbol, and the symbol index starts counting from 0; When multiple synchronization channels are supported in a single time slot, the PSS and SSS in each synchronization channel may use the same or different ZC sequences as the PSS and SSS in other synchronization channels. The system supports multiple PSS and SSS sequences. The number of PSS sequences is defined as 3, and the number of SSS sequences is defined as 11.

10. The method according to claim 1, characterized in that Under different working bandwidths, the system transmits synchronization signals only at candidate frequency domain positions in each subband; the synchronization channel is defined on the synchronization grid, that is, the first resource unit occupied by the synchronization channel is an integer multiple of 15KHz.

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