Frequency Domain Modulation Scheme with Low Peak-to-Average Power Ratio

Abstract

Methods, apparatus, and systems for reducing a peak-to-average power ratio (PAPR) in signal transmission are described. In one example aspect, a wireless communication method includes: determining an output sequence s(k) for a time domain sequence x(i). The output sequence s(k) is an inverse Fourier transform of a frequency domain sequence S(j). S(j) is the output of a frequency domain shaping operation based on a frequency domain sequence Y(j) and a set of coefficients. Y(j) corresponds to a time domain sequence x(i) based on a parameter N. The number of non-zero coefficients in the set of coefficients is based on N, and the values ​​of the non-zero coefficients correspond to phase values ​​distributed between 0 and π / 2 to reduce the peak-to-average power ratio of the output sequence. The method also includes generating a waveform using the output sequence s(k).

Description

Technical Field

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

[0002] Mobile communication technology is pushing the world towards an increasingly connected and networked society. The rapid growth of mobile communication and technological advancements have led to a greater demand for capacity and connectivity. Other aspects such as energy consumption, device cost, spectral efficiency, and latency are also important for meeting the requirements of various communication scenarios. Various technologies are being discussed, including new methods for providing higher quality of service, longer battery life, and improved performance. Summary of the Invention

[0003] This patent document particularly describes techniques for reducing the peak-to-average power ratio (PAPR) in signal transmission.

[0004] In one exemplary aspect, a method for wireless communication includes determining an output sequence s(k) for a time-domain sequence x(i). The output sequence s(k) is the inverse Fourier transform of a frequency-domain sequence S(j). S(j) is the output of a frequency-domain shaping operation based on a frequency-domain sequence Y(j) and a set of coefficients. Y(j) corresponds to the time-domain sequence x(i) based on a parameter N. The number of non-zero coefficients in the set of coefficients is based on N, and the values of the non-zero coefficients correspond to phase values distributed between 0 and π / 2. The method further includes using the output sequence s(k) to generate a waveform, where i ranges from 0 to I - 1, j ranges from 0 to J - 1, k ranges from 0 to K - 1, and I < J <= K. I, J, and K are non-negative integers, and N is a positive integer.

[0005] In another exemplary aspect, a method for wireless communication includes receiving a sequence s(k) generated based on a time-domain sequence x(i). The sequence s(k) is the inverse Fourier transform of a frequency-domain sequence S(j). S(j) is the output of a frequency-domain shaping operation based on a frequency-domain sequence Y(j) and a set of coefficients. Y(j) corresponds to the time-domain sequence x(i) based on a parameter N. The number of non-zero coefficients in the set of coefficients is based on N, and the values of the non-zero coefficients correspond to phase values distributed between 0 and π / . The method further includes demodulating the sequence s(k) to determine the time-domain sequence x(i), where i ranges from 0 to I - 1, j ranges from 0 to J - 1, k ranges from 0 to K - 1, and I < J <= K. I, J, and K are non-negative integers, and N is a positive integer.

[0006] In another exemplary aspect, a communication device is disclosed. The device includes a processor configured to implement the above method.

[0007] In yet another example aspect, a computer program storage medium is disclosed. The computer program storage medium includes code stored thereon. The code, when executed by a processor, causes the processor to implement the described method.

[0008] These and other aspects are described in this document. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a flow chart representation of a wireless communication method according to the present technology.

[0010] Figure 2 is a flowchart representation of another method of wireless communication according to the present technology.

[0011] Figure 3A An example operational sequence according to the present technology is illustrated.

[0012] Figure 3B Another example operational sequence according to the present technology is illustrated.

[0013] Figure 4 An example of a wireless communication system to which the technology according to one or more embodiments of the present technology can be applied is shown.

[0014] Figure 5 is a block diagram representation of a portion of a radio station in which one or more embodiments of the present technology may be applied. DETAILED DESCRIPTION

[0015] The section headings used in this document are intended only to improve readability and do not limit the scope of the embodiments and techniques disclosed in each section to that section. Certain features are described using examples of 5G wireless protocols. However, the applicability of the disclosed techniques is not limited to 5G wireless systems.

[0016] In high-frequency wireless communication scenarios, path loss and shadow attenuation are both relatively large. Therefore, the signal-to-noise ratio in some areas at the edge of the cell is relatively low. In addition, the efficiency of the power amplifier (PA) is relatively low at high frequencies. In order to improve the signal-to-interference-noise ratio (SINR) and also save power consumption of the user equipment (UE), it is hoped that the UE transmits signals with a lower peak-to-average power ratio (PAPR).

[0017] In addition, in the case of massive machine type communication (mMTC), the terminal device may desire to greatly reduce power consumption. For example, in some scenarios, a long battery life (e.g., more than a decade) is required to reduce the need to dispatch maintenance teams to replace the battery. To improve the PA efficiency of such terminal devices, the transmitted signal should have a low PAPR. In particular, when a large number of user devices obtain non-orthogonal access, the SINR is very low. There is a need to use low modulation and coding schemes (MCS) and low PAPR signal modulation to improve the transmission quality.

[0018] In the current fifth-generation (5G) new radio (NR) standard, although the peak-to-average power ratio of DFT-s-OFDM signals is relatively low, it is still difficult to meet the low PAPR requirements of various application scenarios in B5G or 6G. This patent document describes techniques that can be implemented in various embodiments to use modulation schemes that further reduce PAPR.

[0019] Figure 1 is a flowchart representation of a wireless communication method 100 according to the present technology. Method 100 can be implemented by a radio station such as a base station or a wireless device described in this document. For example, a processor in the radio station (e.g., the processor electronic device described in this document) can be configured to implement method 100. Method 100 includes, at operation 110, determining an output sequence s(k) for a time-domain sequence x(i). The output sequence s(k) is the inverse Fourier transform of a frequency-domain sequence S(j). S(j) is the output of a frequency-domain shaping operation based on a frequency-domain sequence Y(j) and a set of coefficients. Y(j) corresponds to the time-domain sequence x(i) based on a parameter N. The set of coefficients can include zero coefficients and non-zero coefficients. The number of non-zero coefficients is based on N, and the values of the non-zero coefficients correspond to phase values distributed between 0 and π / 2 to reduce the peak-to-average power ratio of the output sequence. Method 100 further includes, at operation 120, using the output sequence s(k) to generate a waveform, where i ranges from 0 to I-1, j ranges from 0 to J-1, k ranges from 0 to K-1, I < J <= K, and where I, J, K are non-negative integers and N is a positive integer.

[0020] Figure 2is a flowchart representation of another wireless communication method 200 according to the present technology. Method 200 may be implemented by a wireless station such as a base station or a wireless device described in this document. For example, a processor in the wireless station (e.g., the processor electronic device described in this document) may be configured to implement Method 200. Method 200 includes, at operation 210, receiving a sequence s(k) generated based on a time-domain sequence x(i). The sequence s(k) is the inverse Fourier transform of a frequency-domain sequence S(j), and S(j) is the output of a frequency-domain shaping operation based on a frequency-domain sequence Y(j) and a set of coefficients. Y(j) corresponds to the time-domain sequence x(i) based on a parameter N. The set of coefficients may include zero coefficients and non-zero coefficients. The number of non-zero coefficients in the set of coefficients is based on N, and the values of the non-zero coefficients correspond to phase values distributed between 0 and π / 2 to reduce the peak-to-average power ratio of the output sequence. Method 200 further includes: at operation 220, demodulating the sequence s(k) to determine the time-domain sequence x(i), where i ranges from 0 to I-1, j ranges from 0 to J-1, k ranges from 0 to K-1, and I < J <= K. I, J, and K are non-negative integers, and N is a positive integer.

[0021] In some embodiments, the number of non-zero coefficients is 2N + 1. In some embodiments, the non-zero coefficients are represented as [f(0), f(1),..., f(2N)] = p · [g(0), g(1),..., g(2N)], where p is a scalar value. In some embodiments, the number of non-zero coefficients is 2N + 2. In some embodiments, the non-zero coefficients are [f(0), f(1),..., f(2N + 1)] which is the convolution of p · [g(0), g(1),..., g(2N)] and [h(0), h(1)], where p is a scalar value. In some embodiments, [h(0), h(1)] = [1, 1]. In some embodiments, g(0) = g(2N), g(1) = g(2N - 1),..., and g(N - 1) = g(N + 1), and g(0), g(1), …, and g(N) correspond to phase values distributed between 0 and π / 2. In some embodiments, g(i) = cos(θ i ), 0 ≤ i ≤ N, and 0 ≤ θ i ≤ π / 2.

[0022] In some embodiments, p includes a normalization parameter. The value of p may be 1. The value of p may also be based on N. For example, when N = 1 or when N = 2 In some embodiments, p is the same for all elements. In some embodiments, p may vary for different elements in the sequence.

[0023] In some embodiments, the frequency domain shaping operation includes a point product of Y(j) and a frequency domain sequence Z(j). Z(j) is determined based on a Fourier transform of a non-zero coefficient or set of coefficients. In some embodiments, Y(j) is obtained by performing a Fourier transform on a time domain sequence y(j). The time domain sequence y(j) is formed by inserting N zero coefficients before or after each coefficient of the sequence x(i). The sequence x(i) is generated by mapping data bits to constellation points according to a modulation scheme. In some embodiments, Y(j) is obtained by repeating the frequency domain sequence X(i) N times so that the length of Y(j) is (N+1) times the length of X(i). X(i) is generated by performing a Fourier transform on the time domain sequence x(i), and the time domain sequence x(i) is generated by mapping data bits to constellation points according to a modulation scheme. The advantage of repeating a frequency domain sequence or inserting zero coefficients between coefficients of a time domain sequence is that data with two-step path differences is not affected by the weighted sum of multiple paths. For example, given three paths D -1 , D 0 and D -1 , path D 0 The data in path D will not affect -1 and D 1 Assume that path D -1 The coefficient of is d(-1), path D 0 The coefficient of is d(0), and path D 1 The coefficient of is d(1). In some embodiments, d(0)=1, so that for path D 0 In some embodiments, Therefore, after the multipath delay operation, by superimposing D -1 and D 1 The obtained phase is between the phases of two adjacent elements, thus reducing the PAPR.

[0024] In some embodiments, the sequence x(i) comprises a data sequence or a reference sequence. In some embodiments, the sequence x(i) comprises one or more zero coefficients. In some embodiments, the modulation scheme comprises π / 2-binary phase shift keying (BPSK). The advantage given by using π / 2-BPSK as a modulation scheme is that the phase between every two adjacent elements in the data sequence is π / 2. In some embodiments, after the multipath delay operation, the phase after the superimposed data path has a difference of 0 or π / 4 (e.g., for N=1), or alternatively 0 or π / 6 (e.g., for N=2) with the adjacent elements, thereby reducing the peak-to-average ratio (PAPR) of the resulting data sequence. The phase difference may also be less than π / 6 (e.g., for N>2).

[0025] When the modulation scheme of π / 2-BPSK is combined with the path coefficient, the path data (e.g., D-1 and D 1 ), the modulus value obtained is equal to path D 0 modulus. Therefore, the modulus values ​​of all element data of the data sequence [s(k)] are equal, and the phase difference between adjacent elements is relatively small, thereby reducing the PAPR of the data sequence [s(k)]. In addition, after receiving the data including the data sequence [s(k)], the receiving end obtains the data including the data sequence [x(i)] by using a correlation detection algorithm such as maximum ratio combining, which reduces the processing complexity on the receiving side. During demodulation, the data sequence [x(i)] does not cause error propagation between data elements. In addition, although the length of [s(k)] is doubled compared to the length of [x(i)], which requires more physical resources, the improvement of the signal-to-noise ratio (SNR) (for example, experiments have shown that the SNR can be improved by more than 3dB) can compensate for the loss of transmission efficiency.

[0026] As further described in this document, the above method provides a flexible solution to manipulate the input data sequence for achieving low PAPR. For example, the path delay operation and coefficients can be variable based on the input data sequence (i.e., the value of N can be variable). The modulus (moduli) of all elements of the resulting sequence is the same. In particular, when they are normalized by parameter p, the modulus is equal to 1, which reduces the PAPR. The disclosed technology also imposes low complexity on the transmission and / or receiving end. Some examples of the disclosed technology are described in the following example embodiments.

[0027] Example 1

[0028] The frequency domain data sequence [Y(j)] includes elements [Y(0), Y(1), ..., Y(J-1)]. The frequency domain sequence Y(j) can be determined by repeating the frequency domain sequence X(i) multiple times. For example, X(i) can be repeated to obtain Y(j), where i=0, ..., I-1, j=0, ..., J-1, and J=2I (i.e., each element of X(i) appears twice). In some embodiments, Y(j) is obtained by repeating the frequency domain sequence X(i) N times so that the length of Y(j) is (N+1) times the length of X(i).

[0029] The predefined frequency domain data sequence [Z(j)] includes elements [Z(0), Z(1), ..., Z(J-1)]. Z(j) can be generated based on the time domain data sequence f(n) through an operation such as Fourier transform. The number of non-zero values ​​in the time domain data sequence f(n) is based on the parameter N. For example, f(n) may include 2N+1 non-zero values, which are represented as [f(0), f(1), ..., f(2N)] = p·[g(0), g(1), ..., g(2N)], where p is a scalar value. As another example, f(n) may include 2N+2 non-zero values. In some embodiments, f(n) is represented as where p is a scalar value and is a convolution operation. In some embodiments, [h(0), h(1)] = [1, 1].

[0030] In some embodiments, the elements in g(N) are symmetric. That is, g(0) = g(2N), g(1) = g(2N-1), ..., g(N-1) = g(N+1). In addition, g(0), g(1), ..., and g(N) correspond to phase values ​​distributed between 0 and π / 2. In some embodiments, g(i) = cos(θ i ), 0≤i≤N, and 0≤θ i ≤π / 2.

[0031] In some embodiments, p comprises a normalization parameter. The value of p may be 1. The value of p may also be based on N. For example, when N=1 Or when N = 2 In some embodiments, p is the same for all elements. In some embodiments, p may vary for different elements in the sequence.

[0032] After the dot product of [Y(j)] and [Z(j)], the data sequence [S(j)] is formed as follows:

[0033] [S(j)] = [Y(0)·Z(0), Y(1)·Z(1), ..., Y(J-1)·Z(J-1)], where "·" represents the dot product.

[0034] In some embodiments, the dot product operation is also referred to as a filtering operation of the filter module. The parameters of the filtering operation correspond to the non-zero coefficients f(n).

[0035] In some embodiments, when oversampling is not required, the data sequence [S(j)] is directly subjected to an inverse Fourier transform (IFFT) to form a data sequence [s(k)]. In this case, J=K.

[0036] In some embodiments, when oversampling is required, a plurality of zero coefficients are inserted into the data sequence [S(j)] to form the data sequence [S(k)], and then IFFT is performed to form the data sequence [s(k)]. In this case, J <K。

[0037] In both cases, the data sequence [s(k)] is carried on the physical time-frequency resources for transmission.

[0038] Example 2

[0039] The frequency domain data sequence [Y(j)] includes elements [Y(0), Y(1), ..., Y(J-1)]. The frequency domain sequence Y(j) can be determined by performing a Fourier transform on the time domain data sequence y(j). The time domain data sequence y(j) is determined based on inserting a zero element before or after each element in the time domain data sequence (xi).

[0040] The predefined frequency domain data sequence [Z(j)] includes elements [Z(0), Z(1), ..., Z(J-1)]. Z(j) can be generated based on the time domain data sequence f(n) through an operation such as a Fourier transform. The number of non-zero values ​​in the time domain data sequence f(n) is based on a parameter N. For example, f(n) may include 2N+1 non-zero values, which is represented as [f(0), f(1), ..., f(2N)] = p·[g(0), g(1), ..., g(2N)], where p is a scalar value. As another example, f(n) may include 2N+2 non-zero values. In some embodiments, f(n) is represented as where p is a scalar value and is a convolution operation. In some embodiments, [h(0), h(1)] = [1, 1].

[0041] In some embodiments, the elements in g(N) are symmetric. That is, g(0) = g(2N), g(1) = g(2N-1), ..., g(N-1) = g(N+1). In addition, g(0), g(1), ..., and g(N) correspond to phase values ​​distributed between 0 and π / 2. In some embodiments, g(i) = cos(θ i ), 0≤i≤N, and 0≤θ i ≤π / 2.

[0042] In some embodiments, p comprises a normalization parameter. The value of p may be 1. The value of p may also be based on N. For example, when N=1 Or when N = 2 In some embodiments, p is the same for all elements. In some embodiments, p may vary for different elements in the sequence.

[0043] The data sequence [S(j)] is formed by dot-multiplying the frequency domain data sequence [Y(j)]=[Y(0), Y(1), ..., Y(J-1)] and the frequency domain data sequence [Z(j)]=[Z(0), Z(1), ..., Z(J-1)] as follows:

[0044] [S(j)] = [Y(0)·Z(0), Y(1)·Z(1), ..., Y(J-1)·Z(J-1)], where "·" represents the dot product.

[0045] In some embodiments, when oversampling is not required, the data sequence [S(j)] is directly subjected to an inverse Fourier transform (IFFT) to form a data sequence [s(k)]. In this case, J=K.

[0046] In some embodiments, when oversampling is required, a plurality of zero coefficients are inserted into the data sequence [S(j)] to form the data sequence [S(k)], and then IFFT is performed to form the data sequence [s(k)]. In this case, J <K。

[0047] In both cases, the data sequence [s(k)] is carried on the physical time-frequency resources for transmission.

[0048] Example 3

[0049] The multipath delay operation is defined as Here, D -1 Corresponds to the path with a delay value of -1. 0 Corresponds to the path with a delay value of 0 (i.e. no delay). 1 Corresponds to the path with a delay value of 1. D 2 Corresponds to the path with a delay value of 2.

[0050] The non-zero coefficients for the four paths are

[0051] In some embodiments, p comprises a normalization parameter. The value of p may be 1. The value of p may also be based on N. For example, when N=1 In some embodiments, p is the same for all elements. In some embodiments, p may vary for different elements in the sequence. The frequency domain data sequence [Z(j)] is formed from the Fourier transforms from these delay paths.

[0052] The data sequence [S(j)] is formed by dot-multiplying the frequency domain data sequence [Y(j)]=[Y(0), Y(1), ..., Y(J-1)] and the frequency domain data sequence [Z(j)]=[Z(0), Z(1), ..., Z(J-1)] as follows:

[0053] [S(j)] = [Y(0)·Z(0), Y(1)·Z(1), ..., Y(J-1)·Z(J-1)], where "·" represents the dot product.

[0054] In some embodiments, when oversampling is not required, the data sequence [S(j)] is directly subjected to an inverse Fourier transform (IFFT) to form a data sequence [s(k)]. In this case, J=K.

[0055] In some embodiments, when oversampling is required, a plurality of zero coefficients are inserted into the data sequence [S(j)] to form the data sequence [S(k)], and then IFFT is performed to form the data sequence [s(k)]. In this case, J <K。

[0056] In both cases, the data sequence [s(k)] is carried on the physical time-frequency resources for transmission.

[0057] Example 4

[0058] The multipath delay operation is defined as That is, N = 2. Here, D -2 Corresponds to the path with a delay value of -2. -1 Corresponds to the path with a delay value of -1. 0 Corresponds to the path with a delay value of 0 (i.e. no delay). 1 Corresponds to the path with a delay value of 1. D 2 Corresponding to the path with a delay value of 2. The coefficients of the four paths are and In some embodiments, p includes a normalization parameter. The value of p may be 1. The value of p may also be based on N. For example, when N=2 In some embodiments, p is the same for all elements. In some embodiments, p may vary for different elements in the sequence. The frequency domain data sequence [Z(j)] is formed from the Fourier transforms from these delay paths.

[0059] The data sequence [S(j)] is formed by dot-multiplying the frequency domain data sequence [Y(j)]=[Y(0), Y(1), ..., Y(J-1)] and the frequency domain data sequence [Z(j)]=[Z(0), Z(1), ..., Z(J-1)] as follows:

[0060] [S(j)] = [Y(0)·Z(0), Y(1)·Z(1), ..., Y(J-1)·Z(J-1)], where "·" represents the dot product.

[0061] In some embodiments, when oversampling is not required, the data sequence [S(j)] is directly subjected to an inverse Fourier transform (IFFT) to form a data sequence [s(k)]. In this case, J=K.

[0062] In some embodiments, when oversampling is required, a plurality of zero coefficients are inserted into the data sequence [S(j)] to form the data sequence [S(k)], and then IFFT is performed to form the data sequence [s(k)]. In this case, J <K。

[0063] In both cases, the data sequence [s(k)] is carried on the physical time-frequency resources for transmission.

[0064] Example 5

[0065] Figure 3A An example operation sequence according to the present technology is illustrated. The time domain sequence x(i) can be a data sequence or a reference sequence. The sequence x(i) can also include one or more zeros and constellation modulation data. For example, a user data sequence [b(m)] including 0 and 1 is first modulated by a constellation point to generate a data sequence [x(i)]. Constellation modulation includes π / 2-BPSK, π / 4-quadrature phase shift keying (QPSK), QPSK, 16-quadrature amplitude modulation (QAM) and / or amplitude and phase shift keying (APSK). In some embodiments, the sequence x(i) is part of a data sequence transmitted by a wireless device. The sequence [y(j)] can be generated by inserting zero coefficients into x(i). A zero coefficient can be inserted before each coefficient of x(i). A zero coefficient can also be inserted after each coefficient of x(i).

[0066] After performing the FFT operation on the time domain sequence [y(j)], a frequency domain sequence [Y(j)] is generated. Then, a dot multiplication is performed on [Y(j)] and [Z(j)] to generate [S(j)]. [Z(j)] may be predefined (e.g., as described in the above embodiment). For example, the elements of [Z(j)] are determined based on the time domain coefficients, such as or Then, an IFFT operation is performed on [S(j)] to generate a data sequence [s(k)], where J<=K. Before the IFFT operation, the following steps may be performed: (1) generating a second sequence W(u) by repeating the sequence S(j) multiple times, where u=0, 1, 2, ..., U-1 and U<=K; (2) generating a sequence V(u) by dot-multiplying the second sequence W(u) with a predefined sequence F(u), and (3) performing an inverse Fourier transform using the sequence V(u). Here, J<=U<=K.

[0067] Example 6

[0068] Figure 3BAnother example operation sequence according to the present technology is illustrated. The time domain sequence x(i) can be a data sequence or a reference sequence. The sequence x(i) can also include one or more zero and constellation modulation data. For example, a user data sequence [b(m)] including 0 and 1 is first modulated by a constellation point to generate a data sequence [x(i)]. Constellation modulation includes π / 2-BPSK, π / 4-QPSK, QPSK, 16QAM and / or APSK. In some embodiments, the sequence x(i) is part of a data sequence transmitted by a wireless device. The frequency domain sequence [X(i)] is formed by performing an FFT operation on the sequence x(i).

[0069] The sequence [X(j)] is then repeated multiple times, such as N times, where N>=2, to form a frequency domain sequence [Y(j)]. For example, when N=2, [X(i)]=[X(0), X(1), ..., X(I-1)] and [Y(j)]=[X(0), X(1), ..., X(I-1), X(0), X(1), ..., X(I-1)].

[0070] Then, a dot multiplication is performed on [Y(j)] and [Z(j)] to generate [S(j)]. [Z(j)] may be predefined (e.g., as described in the above embodiments). For example, the elements of [Z(j)] are determined based on the time domain coefficients, such as or Then, an IFFT operation is performed on [S(j)] to generate a data sequence [s(k)], where J <= K. Before the IFFT operation, the following steps may be performed: (1) the sequence S(j) is repeated multiple times to generate a second sequence W(u), where u = 0, 1, 2, ..., U-1 and (2) Generate a sequence V(u) by dot-multiplying the second sequence W(u) with a predefined sequence F(u), and (3) Perform an inverse Fourier transform using the sequence V(u). Here, J<=U<=K.

[0071] In some embodiments, other operations may be performed before the data sequence [s(k)] is carried on the physical time-frequency resources for transmission, such as performing another frequency shaping, adding a reference sequence to the data sequence [s(k)], adding a reference sequence before or after the data sequence [s(k)], and / or filtering the data sequence [s(k)].

[0072] Figure 4An example of a wireless communication system 400 in which various techniques according to one or more embodiments of the present technology can be applied is shown. The wireless communication system 400 may include one or more base stations (BSs) 405a, 405b, one or more wireless devices 410a, 410b, 410c, 410d, and a core network 425. The base stations 405a, 405b may provide wireless services to the wireless devices 410a, 410b, 410c, and 410d in one or more wireless sectors. In some implementations, the base stations 405a, 405b include directional antennas to generate two or more directional beams to provide wireless coverage in different sectors.

[0073] The core network 425 can communicate with one or more base stations 405a, 405b. The core network 425 provides connectivity with other wireless communication systems and wired communication systems. The core network may include one or more service subscription databases to store information related to subscribed wireless devices 410a, 410b, 410c, and 410d. The first base station 405a can provide wireless services based on a first radio access technology, and the second base station 405b can provide wireless services based on a second radio access technology. Depending on the deployment scenario, base stations 405a and 405b can co-exist on site or can be installed separately. Wireless devices 410a, 410b, 410c, and 410d can support a variety of different radio access technologies. The techniques and embodiments described in this document can be implemented by the base stations of the wireless devices described in this document.

[0074] Figure 5 5 is a block diagram representation of a portion of a radio station to which one or more embodiments of the present technology may be applied. A radio station 505, such as a base station or a wireless device (or UE), may include a processor electronic device 510, such as a microprocessor, that implements one or more wireless technologies proposed in this document. The radio station 505 may include a transceiver electronic device 515 to send and / or receive wireless signals through one or more communication interfaces such as an antenna 520. The radio station 505 may include other communication interfaces for transmitting and receiving data. The radio station 505 may include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some implementations, the processor electronic device 510 may include at least a portion of the transceiver electronic device 515. In some embodiments, the radio station 505 is used to implement at least some of the disclosed techniques, modules, or functions.

[0075] It should be understood that this document discloses technologies that can be embodied in various embodiments to effectively reduce the PAPR in signal transmission to meet the low PAPR requirements of various application scenarios. The disclosed and other embodiments, modules and functional operations described in this document can be implemented in digital electronic circuits or computer software, firmware or hardware, including the structures disclosed in this document and their structural equivalents or a combination of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, that is, one or more computer program instruction modules encoded on a computer-readable medium, for execution by a data processing device or for controlling the operation of a data processing device. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a material composition that affects a machine-readable propagation signal, or a combination of one or more of them. The term "data processing device" covers all devices, equipment and machines for processing data, including, for example, a programmable processor, a computer or multiple processors or computers. In addition to hardware, the device may also include code that creates an execution environment for the computer program in question, such as code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, such as a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus.

[0076] A computer program (also referred to as a program, software, software application, script, or code) may be written in any form of programming language, including compiled or interpreted languages, and it may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language file), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or portions of code). A computer program may be deployed to execute on a single computer or on multiple computers located at a single site or distributed across multiple sites and interconnected by a communications network.

[0077] The processes and logic flows described in this document may be performed by executing one or more computer programs by one or more programmable processors to perform functions by operating on input data and generating output. The processes and logic flows may also be performed by, and apparatus may also be implemented as, special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0078] Processors suitable for executing computer programs include, for example, general-purpose and special-purpose microprocessors, and any one or more processors of any type of digital computer. Typically, the processor will receive instructions and data from a read-only memory or a random access memory or both. The basic elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include or be operably coupled to receive data from or transfer data to or both of one or more mass storage devices (e.g., magnetic, magneto-optical disks, or optical disks) for storing data. However, a computer need not have such a device. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, for example, semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; disks, such as internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and memory may be supplemented by or incorporated into a dedicated logic circuit.

[0079] Although this patent document contains many details, these should not be interpreted as limitations on the scope of any invention or what may be claimed, but rather as descriptions of features that may be specific to a particular embodiment of a particular invention. Certain features described in the context of separate embodiments in this patent document may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. In addition, although features may be described as working in certain combinations and even initially claimed as such, in some cases, one or more features from the claimed combination may be deleted from the combination, and the claimed combination may involve a sub-combination or a variation of a sub-combination.

[0080] Similarly, although the operations are depicted in a particular order in the drawings, this should not be understood as requiring that the operations be performed in the particular order shown or in a sequential order, or that all illustrated operations be performed to achieve the desired results. In addition, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

[0081] Only a few implementations and examples are described, and other implementations, enhancements, and variations can be made based on what is described and illustrated in this patent document.

Claims

1. A method for wireless communication, comprising: Determining an output sequence s(k) for a time-domain sequence x(i), the output sequence s(k) being the inverse Fourier transform of a frequency-domain sequence S(j), where S(j) is the output of a frequency-domain shaping operation that includes a point multiplication of a frequency-domain sequence Y(j) and a frequency-domain sequence Z(j), where Z(j) is determined based on the Fourier transform of a set of coefficients, and where Y(j) corresponds to the time-domain sequence x(i) based on a parameter N; where the non-zero coefficients of the set of coefficients are represented as [f(0), f(1), …, f(2N)] = p ● [g(0), g(1), …, g(2N)] or as [f(0), f(1), …, f(2N+1)] which is the convolution of p ● [g(0), g(1), …, g(2N)] and [h(0), h(1)], p being a scalar value, where g(0), g(1), …, g(N) correspond to phase values between 0 and π / 2; and Generating a waveform using the output sequence s(k), where i ranges from 0 to I-1, j ranges from 0 to J-1, k ranges from 0 to K-1, I < J <= K, and where I, J, and K are non-negative integers, and N is a positive integer.

2. The method according to claim 1, wherein g(0) = g(2N), g(1) = g(2N-1), …, and g(N-1) = g(N+1).

3. The method according to claim 1, wherein g(i)=cos(θ i ), 0≤i≤N, and 0≤θ i ≤π / 2.

4. The method according to any one or more of claims 1 to 3, wherein p includes a normalization parameter.

5. The method according to claim 4, wherein p is 1, or 6. The method according to any one or more of claims 1 to 3, wherein Y(j) is obtained by performing a Fourier transform on the time-domain sequence y(j), the time-domain sequence y(j) being formed by inserting N zero coefficients before or after each coefficient of the sequence x(i), and wherein the sequence x(i) is generated by mapping data bits to constellation points according to a modulation scheme.

7. The method according to any one or more of claims 1 to 3, wherein Y(j) is obtained by repeating the frequency-domain sequence X(i) N times such that the length of Y(j) is (N+1) times the length of X(i), where X(i) is generated by performing a Fourier transform on the time-domain sequence x(i), and wherein the time-domain sequence x(i) is generated by mapping data bits to constellation points according to a modulation scheme.

8. The method according to claim 6, wherein the modulation scheme includes π / 2-binary phase shift keying (BPSK).

9. The method according to any one or more of claims 1 to 3, wherein the sequence x(i) includes a data sequence or a reference sequence.

10. The method according to claim 9, wherein the sequence x(i) includes one or more zero coefficients.

11. A wireless communication method, comprising: Receive a sequence s(k) generated based on a time-domain sequence x(i), where the sequence s(k) is the inverse Fourier transform of a frequency-domain sequence S(j), and where S(j) is the output of a frequency-domain shaping operation that includes a pointwise multiplication of a frequency-domain sequence Y(j) and a frequency-domain sequence Z(j), where Z(j) is determined based on the Fourier transform of a set of coefficients, and where Y(j) corresponds to the time-domain sequence x(i) based on a parameter N. where the non-zero coefficients of the set of coefficients are represented as [f(0), f(1), …, f(2N)] = p ● [g(0), g(1), …, g(2N)] or as [f(0), f(1), …, f(2N + 1)] which is the convolution of p ● [g(0), g(1), …, g(2N)] and [h(0), h(1)], p being a scalar value, where [g(0), g(1), …, g(N)] corresponds to phase values between 0 and π / 2; and Demodulate the sequence s(k) to determine the time-domain sequence x(i), where i ranges from 0 to I - 1, j ranges from 0 to J - 1, k ranges from 0 to K - 1, and I < J <= K, and where I, J, K are non-negative integers, and N is a positive integer.

12. The method according to claim 11, wherein g(0) = g(2N), g(1) = g(2N - 1), …, and g(N - 1) = g(N + 1).

13. The method according to claim 12, wherein g(i)=cos(θ i ), 0≤i≤N, and 0≤θ i ≤π / 2.

14. The method according to any one or more of claims 11 to 13, wherein p includes a normalization parameter.

15. The method of claim 14, wherein p is 1, or 16. The method according to any one or more of claims 11 to 13, wherein Y(j) is obtained by performing a Fourier transform on the time-domain sequence y(j), which is formed by inserting N zero coefficients before or after each coefficient of the sequence x(i), and wherein the sequence x(i) is generated by mapping data bits to constellation points according to a modulation scheme.

17. The method according to any one or more of claims 11 to 13, wherein Y(j) is obtained by repeating the frequency-domain sequence X(i) N times such that the length of Y(j) is (N + 1) times the length of X(i), where X(i) is generated by performing a Fourier transform on the time-domain sequence x(i), and wherein the time-domain sequence x(i) is generated by mapping data bits to constellation points according to a modulation scheme.

18. The method according to claim 16, wherein the modulation scheme includes π / 2 - Binary Phase Shift Keying (BPSK).

19. The method according to any one or more of claims 11 to 13, wherein the sequence x(i) includes a data sequence or a reference sequence.

20. The method according to claim 19, wherein the sequence x(i) includes one or more zero coefficients.

21. A communication device comprising a processor configured to implement the method according to any one or more of claims 1 to 20.

22. A computer program product having stored thereon codes which, when executed by a processor, cause the processor to implement the method according to any one or more of claims 1 to 20.

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