Sequence generation method and device

Abstract

Methods, systems, and apparatus for generating sequences for reference signals in mobile communication techniques are described. An exemplary wireless communication method includes sending data and a reference signal using multiple subcarriers, the data being modulated using pi / 2-binary phase shift keying (BPSK) modulation, wherein the reference signal includes a sequence from a subset of sequences, the subset of sequences including 30 sequences, each sequence having a predetermined length, and wherein the subset of sequences includes at least a first number of fixed sequences and a second number of selected sequences. The method also includes enabling the construction of a sequence according to a computer-implementable method, which has a low peak-to-average power ratio (PAPR) for a sequence length N=6.

Description

Technical Field

[0001] This document generally relates to wireless communications. Background Art

[0002] Wireless communication technology is pushing the world towards an increasingly connected and networked society. The rapid growth of wireless communications and technological advances have led to greater demands for capacity and connectivity. Other aspects such as energy consumption, device cost, spectrum efficiency and latency are also important to meet the needs of various communication scenarios. Compared with existing wireless networks, next-generation systems and wireless communication technologies need to provide support for an increased number of users and devices, as well as support for higher data rates, requiring user equipment to implement energy-saving techniques. Summary of the invention

[0003] The present invention relates to methods, systems and devices for generating sequences for reference signals in mobile communication technologies, including fifth generation (5G) communication systems and new radio (NR) communication systems.

[0004] In one exemplary aspect, a wireless communication method is disclosed. The method includes sending data and a reference signal using a plurality of subcarriers, the data being modulated using pi / 2-binary phase shift keying (BPSK) modulation, wherein the reference signal includes a sequence from a subset of sequences, the subset of sequences including 30 sequences, each sequence having a predetermined length, and wherein the subset of sequences includes at least a first number of fixed sequences and a second number of selected sequences.

[0005] In yet another exemplary aspect, the above method is embodied in the form of processor executable code and stored in a computer readable program medium.

[0006] In yet another exemplary embodiment, an apparatus configured or operable to perform the above method is disclosed.

[0007] In another exemplary aspect, a wireless communication method is disclosed. The method includes sending data and a reference signal, wherein the data and the reference signal are modulated using pi / 2-binary phase shift keying (BPSK) modulation, the reference signal includes a sequence from a sequence subset, the size of the sequence subset is greater than 30, the length of each sequence in the sequence subset is greater than 30, the sequence subset is generated using a universal pseudo-random sequence defined by a Gold sequence of length 31, transform precoding is enabled, and wherein the data and the reference signal are sent on a physical uplink shared channel (PUSCH) channel.

[0008] The above and other aspects and embodiments thereof are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A base station in wireless communication according to some embodiments of the disclosed technology is shown.

[0010] Examples of a Base Station (BS) and a User Equipment (UE).

[0011] Figure 2 is a block diagram of an example implementation of a wireless communication device.

[0012] Figure 3 is a block diagram representation of a portion of a device according to some embodiments of the disclosed technology.

[0013] Figure 4 An example of a wireless communication method according to some embodiments of the disclosed technology is shown. DETAILED DESCRIPTION

[0014] The demand for the 4th Generation mobile communication technology (4G), Long-Term Evolution (LTE), Long-Term Evolution Advanced (LTE-Advanced / LTE-A) and the 5th Generation mobile communication technology (5G) is increasing. From the current development trend, 4G and 5G systems are studying the features that support enhanced mobile broadband, ultra-high reliability, ultra-low latency transmission and large-scale connectivity.

[0015] In the new generation of NR (New Radio) technology, the physical uplink control channel (PUCCH) and the physical uplink shared channel (PUSCH) support pi / 2-BPSK modulation to further reduce the peak-to-average power ratio (PAPR) of the signal. Pi / 2-BPSK is generated from a standard BPSK signal by multiplying the symbol sequence with a rotating phasor with a phase increment of pi / 2 per symbol period. Pi / 2-BPSK has the same bit error rate performance as BPSK on a linear channel, however, it exhibits less envelope variation (ie, PAPR), making it more suitable for transmission with nonlinear channels. This improves the power amplifier efficiency cost in mobile terminals at lower data rates.

[0016] The pi / 2-BPSK modulation is used to modulate the data portion of the signal, while the reference signal (or referred to as the DMRS signal in this article) still uses the Zadoff-Chu (ZC) sequence or a computer-generated sequence based on QPSK (quadrature phase shift keying) (referred to as a CGS sequence). The current implementation has shown that if the data portion uses the pi / 2-BPSK modulation and the reference signal uses the ZC sequence or the CGS sequence, the PAPR between the data portion and the reference signal is different, wherein the PAPR of the data portion is lower than the PAPR of the reference signal.

[0017] In the current implementation, when a user sends a PUSCH or PUCCH, the power can be adjusted only for the entire PUSCH or PUCCH; that is, the transmission power of a specific symbol cannot be adjusted individually. Therefore, the PAPR of the data part is not equal to the PAPR of the reference signal part, resulting in the inability to fully utilize the low PAPR performance of pi / 2-BPSK modulation because the power adjustment is based on the higher PAPR of the reference signal. Therefore, higher requirements are placed on the design of the reference signal. Sequence design with a low peak-to-average ratio becomes a problem to be solved.

[0018] In addition, when the sequence length of the reference signal is short (e.g., a sequence of length 6) and if a pi / 2-BPSK modulation sequence is used, the maximum available sequence is 2^6=64. In some embodiments, there is at least one of the 64 sequences based on the possibility of cyclic shift of another sequence. Therefore, after excluding sequences that are cyclically shifted from each other, the available sequences are further reduced. Therefore, for a sequence of length 6, a new sequence design needs to be considered.

[0019] Figure 1 An example of a wireless communication system (e.g., LTE, 5G, or New Radio (NR) cellular network) including a BS 120 and one or more user equipments (UEs) 111, 112, and 113 is shown. In some embodiments, uplink transmissions (131, 132, 133) include a π / 2-BPSK modulated data portion and a reference signal including a sequence described by the disclosed technology. The UE may be, for example, a smartphone, a tablet, a mobile computer, a machine-to-machine (M2M) device, a terminal, a mobile device, an Internet of Things (IoT) device, etc.

[0020] This document uses section headings and subheadings for ease of understanding, rather than limiting the scope of the disclosed techniques and embodiments to certain sections. Therefore, embodiments disclosed in different sections can be used together. In addition, examples from 3GPP New Air (NR) network architecture and 5G protocols are used herein only to aid understanding, and the disclosed techniques and embodiments can be practiced in other wireless systems using communication protocols different from 3GPP protocols.

[0021] Exemplary Embodiment of Sequence Search

[0022] In some embodiments, a mathematical formula may be used to generate sequences with desired cross-correlation characteristics (examples of which will be described in later sections of this document). In these embodiments, when a limited number of sequences are required, one or more sequences in the generated set of sequences may be screened out based on filtering the set of sequences using criteria including a PAPR threshold, an autocorrelation threshold, and a cross-correlation threshold. The sequence search process may be summarized as follows.

[0023] Step 1: Set a PAPR threshold (denoted as PAPR_Threshold), exclude sequences whose PAPRs satisfy PAPR>PAPR_Threshold, and include the remaining sequences in set S1.

[0024] Step 2: This step can be achieved in any of the three ways discussed below.

[0025] Implementation 1: Set a specific cyclic shift autocorrelation predetermined value (expressed as Auto_Threshold), and exclude sequences whose autocorrelation exceeds Auto_Threshold from sequence set S1. The sequence set of remaining sequences is expressed as S2, and go to step 3.

[0026] Implementation method 2: Set a predetermined frequency domain sequence variance value (expressed as FRVar_Threshold), and exclude sequences whose frequency domain variance exceeds FRVar_Threshold from sequence set S1. The sequence set of remaining sequences is expressed as S2, and go to step 3.

[0027] Implementation 3: Set a frequency domain sequence variance predetermined value and a specific cyclic shift autocorrelation predetermined value (respectively denoted as FRVar_Threshold and Auto_Threshold), exclude sequences whose autocorrelation exceeds Auto_Threshold or whose frequency domain variance exceeds FRVar_Threshold from sequence set S1. The sequence set of the remaining sequences is denoted as S2, and go to step 3.

[0028] Step 3: In the sequence set S2, exclude one of the sequence pairs whose mutual correlation is equal to 1. The sequence set of the remaining sequences is denoted as S3; and go to step 4.

[0029] Step 4: Set a predetermined cross-correlation value (denoted as Cross_Threshold), and exclude one of the sequence pairs whose cross-correlation exceeds Cross_Threshold from the sequence set S2. The sequence set of the remaining sequences is denoted as S4. If the number of sequences in S4 is less than the target number of sequences Mtarget , then go to step 5, otherwise go to step 6.

[0030] Step 5: Increase the predetermined value of PAPR_Threshold, Auto_Threshold, FRVar_Threshold, or Cross_Threshold and repeat steps 1 to 4.

[0031] Step 6: Select a target sequence according to one of the following implementations.

[0032] Embodiment 1: Reorder the sequences in S4 in ascending order based on their PAPR. Select the first M target The final target sequence.

[0033] Embodiment 2: Reorder the sequences in S4 in ascending order based on their specific cyclic shift autocorrelations. Select the first M target The final target sequence.

[0034] Implementation 3: Reorder the sequences in S4 in ascending order based on the frequency domain sequence variance. Select the first M target The final target sequence.

[0035] Implementation 4: Calculate the mutual correlation of any two sequences in S4 in ascending order based on their PAPR. Eliminate one of the two sequences with the largest mutual correlation until the number of remaining sequences equals M target .

[0036] In some embodiments, M target =30, that is, 30 sequences can be generated. For example, when the sequence length is 6, the sequence can be expressed as Here, b u (n)∈[-7,-5,-3,-1,1,3,5,7], representing the constellation points of the 8-PSK modulation format.

[0037] Example of screening conditions

[0038] PAPR can be calculated using the following formula:

[0039] PAPR = 10log 10 (|x(t)| 2 / mean(x(t)))

[0040] Here, mean(·) represents an average value (or mean).

[0041] The input of PAPR calculation is the time domain signal. For pi / 2-BPSK modulation, frequency domain shaping (Frequency Domain Spectrum Shaping, FDSS) is usually applied to the pi / 2-BPSK modulated signal to further reduce PAPR. FDSS can be applied to demodulation reference signal (DMRS) symbols and data symbols. PAPR will be different for time domain signals with FDSS and time domain signals without FDSS. Therefore, depending on whether FDSS is applied to the time domain signal of the reference signal, the selected sequence set will be different.

[0042] The autocorrelation / cross-correlation of the series can be calculated as:

[0043] xcorr_coeffs(cs_index)=abs(sum((seq1(cs_index).*conj(seq2))) / length(seq1).

[0044] Here, length() represents the length, seq1 and seq2 are two sequences in the time domain, abs() represents the absolute value, sum() represents the sum, and cs_index represents the cyclic shift of the sequence, and conj represents the conjugate. It can be noted that cs_index>0 means shifting to the left, for example, when seq1=[abcdef], then seq1(1)=[bcdefa], seq1(-1)=[fabcde]. However, in alternative embodiments, the relationship between left shift or right shift can be interchanged.

[0045] When seq1 is identical to seq2, xcorr_coeffs(cs_index) indicates the cyclic shift autocorrelation of the sequences, and when seq1 and seq2 are different, xcorr_coeffs(cs_index) indicates the cross-correlation of the two sequences.

[0046] The frequency domain sequence variance can be calculated as: seq_var=var(abs(fft(seq))). Here, fft() represents discrete Fourier transform, seq is a sequence in the time domain, abs() represents absolute value, and var() represents variance.

[0047] Example of setting filter conditions

[0048] Since the sequence is used for channel estimation, it is expected that the frequency domain response of the sequence is flat. In addition, considering the influence of channel multipath, it is expected that the autocorrelation of adjacent cyclic shifts is small. When the sequence length is 6, in addition to the sequence itself, 5 other sequences can be generated by cyclic shift. In the sequence design described in this patent document, it is expected that the sequence corresponding to the cyclic shift of 1 bit to the left and right of the original sequence is small. It is also expected that the bit autocorrelation is small. By setting different screening conditions, different sequence groups can be generated. Preferably, two sets of screening conditions are set in this patent document (for example, with and without frequency domain shaping (FDSS)).

[0049] Filter condition 1 (no FDSS) : PAPR ≤ 2.3; for sequences associated with ±1 cyclic shift, the maximum value of Auto_corr ≤ 0.2, and for 2 sequences, the maximum value of xcorr_coeffs ≤ 0.96.

[0050] Filter condition 2 (no FDSS) : PAPR ≤ 2.0; for sequences associated with ±1 cyclic shift, the maximum value of Auto_corr ≤ 0.3, for 2 sequences, the maximum value of xcorr_coeffs ≤ 0.96.

[0051] Filter condition 3 (no FDSS) : PAPR ≤ 2.3; for sequences associated with ±1 cyclic shift, the maximum value of Auto_corr ≤ 0.3, for 2 sequences, the maximum value of xcorr_coeffs ≤ 0.933.

[0052] Filter condition 4 (with FDSS) : PAPR ≤ 2.3; for sequences associated with ±1 cyclic shift, the maximum value of Auto_corr ≤ 0.433, for 2 sequences, the maximum value of xcorr_coeffs ≤ 0.96. In addition, after the sequence is transformed into the frequency domain, the variance of the sequence amplitude does not exceed 0.6.

[0053] In addition to the above filtering conditions, demodulation performance for PUSCH / PUCCH may also be considered.

[0054] Example of a specific sequence design

[0055] In some embodiments, the terminal sends data and a reference signal for demodulating data on L (L ≥ 6) subcarriers of K (K ≥ 2) symbols according to the received downlink control information, wherein the reference signal is sent on N subcarriers of one or more of the K symbols (the symbol for sending the reference signal is the reference signal symbol). When the downlink control information indicates that the terminal uses pi / 2-BPSK modulation for data modulation, after discrete Fourier transform (DFT), the sequence is sent on N subcarriers of the reference signal symbol.

[0056] As a specific exemplary embodiment, the sequence corresponding to the integer (sequence) index u (u=0, 1, ..., 29) is given by the following formula: Here, n=0, 1, 2, ..., N-1, b u (n)∈[-7,-5,-3,-1,1,3,5,7]. When N=6, u and b u The value of (n) may be as shown in the various embodiments shown in Table 1, Table 2, Table 3, or Table 4.

[0057] In some embodiments, the index u is determined by at least one of:

[0058] ● Determine the sequence index u based on the cell identifier; or

[0059] ●Determine the sequence index u according to the indication signaling of the base station.

[0060] For filter condition 1, the resulting sequences are shown in Table 1.

[0061] Table 1: b for N=6 u (n) value

[0062]

[0063] The PAPR and cross-correlation of the sequence set in Table 1 have the following characteristics:

[0064]

[0065] As a specific exemplary embodiment, when the sequence length is N=6, the sequence set includes at least one of the following sequences:

[0066] Sequence 1: b(n) = {-7, -7, -5, 1, -5, 7},

[0067] Sequence 2: b(n) = {-7, -7, -5, 3, -3, 5},

[0068] Sequence 3: b(n) = {-7, -7, -5, 7, 1, 7},

[0069] Sequence 4: b(n) = {-7, -7, -3, 5, -1, 7},

[0070] Sequence 5: b(n) = {-7, -5, -3, -1, -7, 3},

[0071] Sequence 6: b(n) = {-7, -5, -3, -1, 5, -1},

[0072] Sequence 7: b(n) = {-7, -5, 1, -3, 7, 5},

[0073] Sequence 8: b(n) = {-7, -3, -7, 5, -1, 5},

[0074] Sequence 9: b(n) = {-7, -3, -5, 5, -1, 5},

[0075] Sequence 10: b(n) = {-7, -3, 1, 7, 1, -5},

[0076] Sequence 11: b(n) = {-7, -3, 1, 7, 1, -3},

[0077] Sequence 12: b(n) = {-7, -5, 5, 3, 7, -1}, or

[0078] Sequence 13: b(n) = {-7, 3, -5, -1, -3, 7}.

[0079] For filter condition 2, the resulting sequences are shown in Table 2.

[0080] Table 2: b for N=6 u (n) value

[0081]

[0082] The PAPR and cross-correlation of the sequence set in Table 2 have the following characteristics:

[0083]

[0084] As a specific exemplary embodiment, when the sequence length is N=6, the sequence set includes at least one of the following sequences:

[0085] Sequence 1: b(n) = {-7, -7, -5, -3, 3, -3},

[0086] Sequence 2: b(n) = {-7, -7, -5, -3, 5, -1},

[0087] Sequence 3: b(n) = {-7, -7, 3, -3, 5, 7},

[0088] Sequence 4: b(n) = {-7, -7, 5, -1, 5, 7},

[0089] Sequence 5: b(n) = {-7, -5, -7, 3, -3, 5}, or

[0090] Sequence 6: b(n) = {-7, -5, -1, 7, 1, -5}.

[0091] For filter condition 3, the resulting sequences are shown in Table 3.

[0092] Table 3: b for N=6u (n) value

[0093]

[0094] The PAPR and cross-correlation of the sequence set in Table 3 have the following characteristics:

[0095]

[0096] For filter condition 4, the resulting sequences are shown in Table 4.

[0097] Table 4: b for N=6 u (n) value

[0098]

[0099] The PAPR and cross-correlation of the sequence set in Table 4 have the following characteristics:

[0100]

[0101] As a specific exemplary embodiment, when the sequence length is N=6, the sequence set includes at least one of the following sequences:

[0102] Sequence 1: b(n) = {-7, -3, -7, 5, 1, 5},

[0103] Sequence 2: b(n) = {-7, -3, -7, -3, 1, -3},

[0104] Sequence 3: b(n) = {-7, -5, 7, 1, -3, 5},

[0105] Sequence 4: b(n) = {-7, -5, -7, 3, -1, 5},

[0106] Sequence 5: b(n) = {-7, -5, -1, 5, 1, -5},

[0107] Sequence 6: b(n) = {-7, -7, -1, 1, -5, 1},

[0108] Sequence 7: b(n) = {-7, -7, 1, 7, 1, 3},

[0109] Sequence 8: b(n) = {-7, -5, 1, -5, 1, -5},

[0110] Sequence 9: b(n) = {-7, -5, -1, 5, 1, -3},

[0111] Sequence 10: b(n) = {-7, -5, -7, 3, -7, 3},

[0112] Sequence 11: b(n) = {-7, -5, 7, 3, -1, 5},

[0113] Sequence 12: b(n) = {-7, -7, 7, 1, -5, 3},

[0114] Sequence 13: b(n) = {-7, -7, -1, 7, 1, -5},

[0115] Sequence 14: b(n) = {-7, -5, 7, -5, 5, 1},

[0116] Sequence 15: b(n) = {-7, -3, 1, -5, 1, -5}, or

[0117] Sequence 16: b(n) = {-7, -3, -5, 5, -5, 5}.

[0118] As shown in the above exemplary embodiment, u and b u Various mappings of (n) have been used to provide further understanding of the disclosed technology. These embodiments are used to explain the disclosed technology rather than to limit its scope.

[0119] Embodiments of the disclosed technology advantageously result in low peak-to-average ratio, small cubic metric and high power amplifier efficiency. In one example, when the sequence indexes used by adjacent cells are different, the method also has the effect of reducing inter-cell interference and improving overall system performance.

[0120] Embodiments of the disclosed technology

[0121] Figure 2 A block diagram representing the architecture of a communication device such as a user equipment (UE) terminal or a wireless communication device 200 is described. The terminal 200 may include one or more processor electronics 210, such as a microprocessor that implements one or more of the wireless technologies presented herein. The terminal 200 may include a transmitter electronics 215 and a receiver electronics 220 to send and / or receive wireless signals through one or more communication interfaces such as an antenna 220. In some embodiments, the transmitter electronics 215 and the receiver electronics 220 may be integrated into a single electronic transceiver unit or module. The terminal 200 may include other communication interfaces for sending and receiving data. The terminal 200 may include one or more memories 205, which are configured to store information such as data and / or instructions related to the methods disclosed herein. In some embodiments, the processor electronics 210 may include at least a portion of the transceiver electronics 215. In some embodiments, a sequence generation module 225 is used to implement at least some of the disclosed techniques, modules, or functions.

[0122] Implementation of DMRS generation when the sequence length is large

[0123] Figure 3 is a block diagram representation of a portion of a device according to some embodiments of the disclosed technology. For example, Figure 3 A DMRS sequence generator 304 and a pi / 2-BPSK module 302 coupled to a DFT module 306 are shown. The DFT module 306 is coupled to a frequency mapping module 308, which is coupled to an IFFT (Inverse Fast Fourier Transform) module 310. The output of the DMRS sequence generator 304 is an 8-PSK symbol. When the PUSCH channel symbol is not modulated by pi / 2-BPSK, the DMRS symbol can be inserted directly into the frequency domain. In an embodiment, when transform precoding is enabled and the PUSCH symbol is modulated using pi / 2-BPSK, a computer generated sequence (CGS) for the DMRS symbol can be inserted in the time domain. Figure 3 An embodiment of generating DMRS symbols before DFT operation is shown. The DMRS sequence can also be modulated by pi / 2-BPSK modulation in the same way as the PUSCH channel symbols. The PAPR of the DMRS symbol can be maintained at the same level as the PUSCH channel symbol.

[0124] The DMRS sequence before π / 2-BPSK modulation may consist of a group of bits, each of which has a value of 0 or 1. In other words, each bit (e.g., b(i)) of the DMRS sequence is modulated by π / 2-BPSK modulation, and the bit is mapped to a complex-valued modulation symbol d(i) according to the following formula:

[0125] When the DMRS sequence length is large (e.g., equal to or greater than 30), i.e., i>=30, using a computer-generated sequence for b(i) may be challenging because it is not possible to manually search for the sequence. In such an embodiment, a universal pseudo-random sequence defined by a Gold sequence of length 31 may be used to generate b(i). As shown in current wireless standards, the sequence initialization value c may be used to generate b(i). init to generate the output Gold sequence c(n). Then b(i) can be replaced by c(n), where i and n are the indices of the DMRS sequence. Although this pre-DFT DMRS sequence generation using pi / 2-BPSK is only used for DFT-spread-OFDM (DFT-s-OFDM), i.e., transform precoding is enabled, it is also useful for generating c for CP-OFDM (Cyclic Prefix Orthogonal Frequency Division Multiplexing). init The formula can be reused according to the following formula:

[0126]

[0127] n may be initialized according to one of the following implementations discussed below:SCID The value of .

[0128] For initialization n SCID Implementation method of the value 1 : For CP-OFDM, the 1-bit DCI 'DMRS sequence initialization' field dynamically indicates n SCID However, there is no such field in the DCI for DFT-s-OFDM. In some embodiments, n SCID is set to zero.

[0129] For initialization n SCID Implementation method of value 2 : Since the DMRS sequence is inserted before the DFT operation, when n SCID When the value of is set to zero, the amplitude of the DMRS symbol in the frequency domain may not be constant after the DFT operation. Different DMRS sequences before DFT may result in different levels of flatness in the frequency domain. In other words, based on n SCID =0 init Value and based on n SCID =1c init The values ​​may result in different levels of flatness in the frequency domain. The better the flatness in the frequency domain, the better the channel estimate. It is then preferred that a network device such as a gNB indicates n SCID , to provide more flexibility. In other words, the gNB can choose n SCID A value of , and if the selected n SCID The value can introduce better flatness in the frequency domain, and this value can be sent to the UE. Therefore, in order to obtain more flexibility, a new bit n can be introduced in the DCI when transform precoding is enabled, that is, when transform precoding is enabled for DFT-s-OFDM. SCID However, when transform precoding is enabled, the new bits can generate a new DCI format.

[0130] For initialization n SCID Implementation method of value 3 In some implementations, the DMRS port indication field, such as the "antenna port" field in the DCI, may be used to indicate when the PUSCH channel symbol is modulated by pi / 2-BPSK. SCID The value of .

[0131] As shown in Tables 6 and 7 below, when the PUSCH channel symbol is not modulated by pi / 2-BPSK, a 2-bit and / or 4-bit "antenna port" field is used to indicate DMRS port information for DFT-s-OFDM.

[0132] Table 6: Antenna port, transform precoder enabled, DMRS-Type = 1, maxLength = 1

[0133]

[0134] Table 7: Antenna port, transform precoder enabled, DMRS-Type = 1, maxLength = 2

[0135]

[0136] Since the UE is usually power-limited if demodulated by pi / 2-BPSK, it cannot usually be co-scheduled by other UEs. Therefore, a maximum of two antenna ports and a maximum of four antenna ports are sufficient for maxLength=1 and maxLength=2, respectively. Therefore, as shown in Tables 8 and 9 below, 1 bit and 3 bits may be sufficient for DMRS port indication, respectively. The remaining one bit may be used to indicate n SCID The value of .

[0137] For initialization n SCID Implementation of the value 4 : In some embodiments, when PUSCH channel symbols are demodulated using pi / 2-BPSK, the maximum number of DMRS ports may be limited to 1. In these embodiments, a smaller number of bits (sometimes no bits) are required for DMRS port indication. Therefore, n SCID The value of can be 0 to N. N can be greater than 1, for example 2, 3, 4, 5, 6, or 7.

[0138] Table 8: Antenna port, transform precoder enabled, DMRS-Type = 1, maxLength = 1

[0139]

[0140] Table 9: Antenna port, transform precoder enabled, DMRS-Type = 1, maxLength = 2

[0141] value Number of DMRS CDM groups without data DMRS Port Number of front load symbols 0 2 0 1 1 2 1 1 2 2 0 2 3 2 1 2 4 2 2 2 5 2 3 2 6-7 reserve reserve reserve

[0142] For initialization n SCID Implementation of the value 5 In some embodiments, when PUSCH channel symbols are demodulated using pi / 2-BPSK, the DMRS port information and n can be jointly encoded. SCID The values ​​are, for example, as shown in Tables 10 and 11.

[0143] Table 10: Antenna port, transform precoder enabled, DMRS-Type = 1, maxLength = 1

[0144]

[0145] Table 11: Antenna port, transform precoder enabled, DMRS-Type = 1, maxLength = 2

[0146]

[0147] Therefore, the interpretation of the DMRS port indication field in the DCI is based on the MCS (Modulation and Coding Strategy) indication. If the MCS field in the DCI indicates the pi / 2-BPSK modulation order, the DMRS port indication field can be used to indicate the value of the DMRS sequence initialization. In some embodiments, the interpretation of the DMRS port indication field in the DCI is based on the MCS field, transform precoding and high-level parameters. If the high-level parameters indicate (before the DFT operation) the use of a new DMRS sequence (a sequence based on pi / 2-BPSK), transform precoding is enabled, and the MCS field in the DCI indicates the pi / 2-BPSK modulation order, the DMRS port indication field can be used to indicate the value of the DMRS sequence initialization. If the new DMRS sequence is not configured by the high-level parameters, the Rel-15 (Release 15) DMRS sequence can be used when transform precoding is enabled, and the MCS field in the DCI can indicate the pi / 2-BPSK modulation order. This is because legacy UEs or some new UEs may not be able to support the new DMRS sequence.

[0148] Exemplary Methods of the Disclosed Technology

[0149] Figure 4 An example of a wireless communication method 400 for generating a sequence for a reference signal in a mobile communication technology is shown. The method 400 includes: at step 410, data and a reference signal are sent using a plurality of subcarriers, the data being modulated using pi / 2-binary phase shift keying (BPSK) modulation, and the reference signal comprising a sequence from a sequence subset of size 30.

[0150] In some embodiments, the sequence subset includes 30 sequences, each sequence having a predetermined length (e.g., N=6), and includes at least a first number of fixed sequences (as represented in the specific exemplary embodiment herein) and a second number of selected sequences (to be selected from the table provided herein).

[0151] In some embodiments, the cross-correlation between the first sequence and the second sequence is less than a threshold.

[0152] In some embodiments, data and reference signals are sent on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH). In other embodiments, the data includes uplink traffic data and uplink control information. In other embodiments, the reference signal is used to demodulate the data. In one aspect, the sequences described and constructed in the embodiments of the disclosed technology advantageously achieve improved demodulation performance due to their PAPR and CM (cubic metric) correlation properties.

[0153] Instructions and Appendix Figure 1 The examples should be considered as merely exemplary, where exemplary, unless otherwise specified, means that the examples do not imply an ideal or preferred embodiment. As used herein, the use of "or" is intended to include "and / or" unless the context clearly indicates otherwise.

[0154] Some embodiments described herein are described in the general context of methods or processes, which in one embodiment can be implemented by a computer program product contained in a computer-readable medium, including computer executable instructions, such as program code, executed by a computer in a networked environment. Computer-readable media may include removable and non-removable storage devices, including but not limited to: read-only memory (ROM), random access memory (RAM), compact disk (CD), digital versatile disk (DVD), etc. Therefore, computer-readable media may include non-transitory storage media. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. Computer executable instructions or processor executable instructions, related data structures, and program modules represent examples of program codes for performing the steps of the methods disclosed herein. Specific sequences of such executable instructions or related data structures represent examples of corresponding actions for implementing the functions described in these steps or processes.

[0155] Some disclosed embodiments can be implemented as devices or modules using hardware circuits, software, or a combination thereof. For example, a hardware circuit implementation may include discrete analog and / or digital components, such as integrated as a part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as application specific integrated circuits (ASICs) and / or field programmable gate arrays (FPGAs) devices. Some embodiments may additionally or alternatively include a digital signal processor (DSP), which is a dedicated microprocessor with an architecture optimized for the operational needs of digital signal processing associated with the disclosed functionality of the present application. Similarly, various components or subcomponents within each module may be implemented in software, hardware, or firmware. The connection between the modules and / or components within the modules may be provided using any of the connection methods and media known in the art, including but not limited to communication via the Internet, wired, or wireless networks using appropriate protocols.

[0156] Although many details are included herein, these details should not be interpreted as limitations on the scope of the claimed invention or the scope that may be claimed, but should be interpreted as descriptions of features peculiar to a particular embodiment. Certain features described in the context of each embodiment herein may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. In addition, although features may be described above as working with certain combinations, and even initially claimed as such, one or more features from the claimed combination may be removed from the combination in some cases, and the claimed combination may be for a variation of a sub-combination or a sub-combination. Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order shown or in a continuous order, or requiring all operations shown to be performed to achieve desired results.

[0157] Only a few implementations and examples are described, and other implementations, enhancements, and variations may be made based on what is described and illustrated in this disclosure.

Claims

1. A wireless communication method, comprising: transmitting data and a reference signal using a plurality of subcarriers, wherein the data and the reference signal are modulated using pi / 2-binary phase shift keying (BPSK) modulation, the reference signal comprises a sequence from a sequence subset, the size of the sequence subset is greater than 30, the length of each sequence in the sequence subset is greater than 30, the sequence subset is generated using a universal pseudo-random sequence defined by a Gold sequence of length 31, transform precoding is enabled, and wherein the data and the reference signal are transmitted on a physical uplink shared channel (PUSCH) channel; The length-31 Gold sequence is initialized according to a value sent by a network device; the value sent by the network device has an association with a demodulation reference signal (DMRS) port indication field included in an uplink grant control from the network device.

2. The method according to claim 1, wherein: The association with the DMRS port indication field is enabled only when the Gold sequence with a length of 31 is configured as the DMRS in the PUSCH channel through high-layer signaling from the network device.

3. The method according to claim 1, wherein: The length of each sequence in the sequence subset is 6, and the corresponding sequences included in the reference signal are represented as b u (n) is the u-th sequence in the subset of sequences, wherein u=0, 1, ..., 29, u is an integer indexing the sequence in the subset of sequences, and wherein n=0, 1, ..., 5, n is an integer indexing the bits in the sequence, e is the base of the natural logarithm, j represents the imaginary unit, The sequence subset includes at least one of the following sequences: {-7,-7,-3,1,5,-1}， {-7,-3,-7,5,-1,5}， {-7,-7,-1,1,-5,1}。 4. The method according to claim 1, wherein: The first sequence and the second sequence are any two sequences in the sequence subset, and a mutual correlation between the first sequence and the second sequence is less than a predetermined threshold.

5. The method according to any one of claims 1 to 4, wherein: The data includes uplink service data and uplink control information.

6. The method according to any one of claims 1 to 4, wherein: The reference signal is used to demodulate the data.

7. A wireless communication device, comprising a processor and a memory, wherein the processor is configured to read a code from the memory and implement the method according to any one of claims 1 to 6.

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