Techniques for using discrete spectra

Abstract

The present application discloses techniques for using discrete spectra, and specifically describes methods, apparatuses, and systems for effectively utilizing dispersed narrow spectra without introducing mutual interference between adjacent frequency bands. In one exemplary aspect, a wireless communication method includes: determining a set of time-domain symbols by applying an inverse Fourier transform to a set of processed data modulated on a plurality of subcarrier groups. Each subcarrier group contains an even number of subcarriers, and adjacent subcarrier groups are separated by one or more unused subcarriers. The set of processed data is determined by applying a first spreading code to data carried in a subcarrier group having 2×m subcarriers when m is a positive odd number, and applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers when n is a positive even number. The method further includes transmitting the set of time-domain symbols.

Description

[0001] This application is a divisional application of a Chinese patent application with the application number "201880099496.9", the application date "December 5, 2018", and the title "Techniques for Using Discrete Spectrums". Technical Field

[0002] This patent document generally relates to wireless communication. Background Art

[0003] Mobile communication technologies are pushing the world towards an increasingly interconnected and networked society. The rapid development of mobile communication and technological progress have led to higher demands 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 techniques, including new methods for providing higher service quality, longer battery life, and improved performance, are under discussion. Summary of the Invention

[0004] Among other things, this patent document describes techniques for effectively utilizing dispersed narrow spectrums without introducing interfering spectrums between adjacent frequency bands, thereby improving the resource utilization rate for wireless communication systems.

[0005] In one exemplary aspect, a wireless communication method is disclosed. The method includes determining a set of time-domain symbols by applying an inverse Fourier transform to a set of processed data modulated on multiple subcarrier groups. Each subcarrier group includes an even number of subcarriers, and adjacent subcarrier groups are separated by one or more unused subcarriers. When m is a positive odd number, the processed data set is determined by applying a first spreading code to the data carried in a subcarrier group having 2×m subcarriers, and when n is a positive even number, the processed data set is determined by applying one or more spreading codes to the data carried in a subcarrier group having 2×n subcarriers. The method further includes transmitting the set of time-domain symbols.

[0006] In another exemplary aspect, a wireless communication method is disclosed. The method includes receiving a set of time-domain symbols that carry a set of processed data modulated on one or more subcarrier groups. Each subcarrier group includes an even number of subcarriers. The set of processed data corresponds to the output of: when m is a positive odd number, applying a first spreading code to the data carried in a subcarrier group having 2×m subcarriers, and when n is a positive even number, applying one or more spreading codes to the data carried in a subcarrier group having 2×n subcarriers. The method further includes demodulating the set of time-domain symbols to obtain the data.

[0007] In another exemplary aspect, a communication device is disclosed. The device includes a processor configured to implement the above method.

[0008] In yet another exemplary aspect, a computer program storage medium is disclosed. The computer program storage medium includes code stored thereon. When the code is executed by a processor, the processor is caused to implement the described method.

[0009] These and other aspects are described in this document. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic diagram showing the generation of sidelobes of overlapping spectra between subcarriers in the frequency domain.

[0011] Figure 2 is a flowchart representation of a wireless communication method according to one or more embodiments of the present technology.

[0012] Figure 3 is a flowchart representation of another wireless communication method according to one or more embodiments of the present technology.

[0013] Figure 4 Shows an example of extending layer one data according to one or more embodiments of the present technology.

[0014] Figure 5A Shows another example of extending layer one data according to one or more embodiments of the present technology.

[0015] Figure 5B Shows another example of extending layer one data according to one or more embodiments of the present technology.

[0016] Figure 5C Shows yet another example of extending layer one data according to one or more embodiments of the present technology.

[0017] Figure 6 Shows an example of extending multi-layer data according to one or more embodiments of the present technology.

[0018] Figure 7 Shows an example of extending multi-layer data according to one or more embodiments of the present technology.

[0019] Figure 8 Shows an example of a wireless communication system in which the techniques according to one or more embodiments of the present technology can be applied.

[0020] Figure 9 is a block diagram representation of a part of a radio station to which the wireless communication method according to one or more embodiments of the present technology can be applied. DETAILED DESCRIPTION

[0021] The chapter titles used in this document are for readability only and do not limit the scope of the embodiments and techniques disclosed in each chapter to that chapter alone. Examples using 5G wireless protocols are used to describe certain features. However, the disclosed techniques are not limited in their applicability to only 5G wireless systems.

[0022] In the field of telecommunications, Long-Term Evolution (LTE) is the fourth-generation (4G) standard for high-speed wireless communication. LTE systems employ Orthogonal Frequency Division Multiplexing (OFDM) technology, which has been widely used in wireless communication. For example, Cyclic Prefix (CP) OFDM (CP-OFDM) systems can solve the multipath delay problem and divide the frequency-selective channel into a set of parallel flat channels, thus simplifying channel estimation and providing higher channel estimation accuracy. However, because of the fact that OFDM technology introduces a relatively high level of out-of-band (OOB) scattering due to the sidelobes of the subcarriers, the performance of CP-OFDM systems is sensitive to frequency offset and time offset between adjacent sub-bands. OOB scattering may cause strong interference to adjacent frequency bands. Figure 1 A schematic diagram showing the sidelobes 101 that generate overlapping spectra between subcarriers in the frequency domain is shown. To reduce the impact of OOB scattering, the edges of the transmission band can dedicate specific frequencies to a guard interval to reduce the impact of out-of-band leakage on adjacent bands. However, the guard interval introduces losses in the band and reduces the spectral efficiency.

[0023] The Third Generation Partnership Project (3GPP) standard for the Fifth Generation (5G) New Radio (NR) still provides a CP-OFDM-based waveform for communication. When the subcarrier spacing between adjacent sub-bands is different, interference may exist between adjacent sub-bands. Although spectral leakage and interference between sub-bands can be slightly reduced by techniques such as soft CP or filtering methods, a guard interval that reduces spectral efficiency is still required between sub-bands with different subcarrier spacings.

[0024] Currently, there are many scattered idle spectra with very narrow bandwidths in the wireless spectrum resources. These spectra are usually used as guard bands to prevent interference between frequency bands. Transmission using these scattered idle spectra can improve resource utilization, but there is currently no practical method to achieve this without interfering with existing communication systems in adjacent frequency bands. For example, applying filters to each scattered idle spectrum for interference suppression can suppress interference between sub-bands, but it brings great complexity in communication system design. The filter may also cause inter-symbol interference because each scattered idle spectrum is very narrow.

[0025] This patent document discloses techniques that can be implemented in various embodiments to improve spectrum utilization by using scattered idle spectrum without causing sub-band interference to existing communication systems. The disclosed techniques also allow the same processing procedure to be used to process multiple discrete spectrums, thereby reducing the design complexity of the communication system.

[0026] Figure 2 is a flowchart representation of a wireless communication method 200 according to one or more embodiments of the present technology. Method 200 includes, at step 201, determining a set of time-domain symbols by applying an inverse Fourier transform to a set of processed data modulated on multiple subcarrier groups. Each subcarrier group contains an even number of subcarriers, and adjacent subcarrier groups are separated by one or more unused subcarriers. The set of processed data is determined by applying a first spreading code to the data carried in a subcarrier group having 2×m subcarriers when m is a positive odd number, and applying one or more spreading codes to the data carried in a subcarrier group having 2×n subcarriers when n is a positive even number. Method 200 further includes, at step 202, transmitting the set of time-domain symbols.

[0027] For example, data is modulated on M subcarrier groups in a discrete spectrum, where M≥2. Each subcarrier group includes 2×n subcarriers. The subcarrier groups are separated by K(m)≥1 unused subcarriers (e.g., subcarriers carrying 0). The unused subcarriers correspond to the spectrum of an existing communication system used for data transmission. In some cases, a subcarrier group may include an odd number of subcarriers. Padding subcarriers in adjacent unused subcarriers can be added to the group to ensure that each group has an even number of subcarriers. Alternatively, subcarriers in a subcarrier group can be added to adjacent unused subcarriers to ensure that each group has an even number of subcarriers.

[0028] In some embodiments, the respective subcarrier groups include different numbers of subcarriers - that is, for each subcarrier group, the value of n changes. For example, one subcarrier group includes two subcarriers, while another subcarrier group includes four subcarriers. In some embodiments, n is a fixed value, and each subcarrier group includes the same number of subcarriers. Since the scattered spectrum can be very narrow, in some embodiments, K(m)≥2×n, which indicates that the unused subcarriers (e.g., subcarriers carrying 0) are wider than the scattered spectrum.

[0029] In some embodiments, when n is odd, the data modulated on 2×n subcarriers is spread using the spreading code [1, -1]. When n is even, the data modulated on 2×n subcarriers can be spread using at least one of the following spreading codes: [1, -1], [1, -1, -1, 1], [1, -1, 1, -1], or [1, 1, -1, -1]. For example, the data can be spread using [1, -1]. The data can also be spread using [1, -1, -1, 1]. In some embodiments, multi-layer data in a multi-carrier system can be spread using multiple spreading codes (e.g., [1, -1, -1, 1] and [1, -1, 1, -1]). In some embodiments, the data in different sub-carrier groups is spread using different codes (e.g., [1, -1, -1, 1] and [1, -1, 1, -1]). Similarly, in some embodiments, multi-layer data in a multi-carrier system can be spread using [1, -1, -1, 1], [1, -1, 1, -1], and [1, 1, -1, -1]. The data carried in different sub-carrier groups can be spread using different codes, such as [1, -1, -1, 1], [1, -1, 1, -1], and [1, 1, -1, -1].

[0030] In some embodiments, due to the low peak-to-average ratio of the uplink traffic, the uplink data modulated onto 2×n subcarriers is spread using the code [1, -1]. The downlink data modulated onto 2×n subcarriers can be spread using one or more of the following codes: [1, -1, -1, 1], [1, -1, 1, -1], or [1, 1, -1, -1]. For example, when there is only one layer of data, the data is spread using the code [1, -1, -1, 1]. When two layers of data are transmitted, the two spreading codes [1, -1, -1, 1] and [1, -1, 1, -1] can be used to spread the data. The spread data occupies the same sub-carrier resources through code-division multiplexing. Similarly, when three layers of data are transmitted, the three spreading codes [1, -1, -1, 1], [1, -1, 1, -1], and [1, 1, -1, -1] are used to spread the data. The spread data occupies the same sub-carrier resources through code-division multiplexing.

[0031] Figure 3is a flowchart representation of a wireless communication method 300 according to one or more embodiments of the present technology. The method 300 includes, at step 301, receiving a set of time-domain symbols that carry a set of processed data modulated on one or more subcarrier groups. Each subcarrier group includes an even number of subcarriers. The set of processed data corresponds to the output of applying a first spreading code to data carried in a subcarrier group having 2×m subcarriers, where m is a positive odd number, and applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers, where n is a positive even number. The method 300 further includes, at step 302, demodulating the set of time-domain symbols to obtain the data.

[0032] Using the above method, a discrete spectrum in the form of discrete subcarrier groups can be processed by a single set of baseband processing procedures, thereby reducing the complexity of the communication system design. Since the subcarrier groups are separated by unused subcarriers (e.g., subcarriers carrying 0), data transmitted through the discrete and dispersed spectrum can overlap with data in existing communication systems in the time domain.

[0033] Some examples of the disclosed technology are described in the following exemplary embodiments.

[0034] Embodiment 1

[0035] Figure 4 Shows an example of spreading layer 1 data according to one or more embodiments of the present technology. The data is modulated onto three subcarrier groups in the frequency domain. Here, each subcarrier group includes the same number of 2×n subcarriers: n = 1. The subcarrier groups are separated by one or more unused subcarriers (i.e., subcarriers that do not carry data). For example, the first subcarrier group 401 and the second subcarrier group 402 are separated by three unused subcarriers (e.g., three subcarriers carrying 0). The second subcarrier group 402 and the third subcarrier group 403 are separated by four unused subcarriers (e.g., four subcarriers carrying 0).

[0036] In some embodiments, unused subcarriers are also included on both sides of the frequency-domain data. For example, as Figure 4 shown, two unused subcarriers are on one side of the first subcarrier group 401, while two unused subcarriers are on the other side of the third subcarrier group 403.

[0037] Since n is odd, when transmitting one layer of data, the data carried by the two subcarriers included in each subcarrier group can be spread by the spreading code [1, -1]. For example, when the data carried in the subcarrier group is D, the data modulated onto the two subcarriers in the subcarrier group is D and -D. The frequency-domain data of each symbol is processed by the inverse Fourier transform 404 to obtain the time-domain data.

[0038] Embodiment 2

[0039] Figure 5A Shows another example of spreading one layer of data according to one or more embodiments of the present technology. The data is modulated onto two subcarrier groups in the frequency domain. Here, each subcarrier group includes the same number of 2×n subcarriers: n = 2. The subcarrier groups are separated by one or more unused subcarriers (i.e., subcarriers that do not carry data). For example, the first subcarrier group 501 and the second subcarrier group 502 are separated by five unused subcarriers (e.g., five subcarriers carrying 0).

[0040] In some embodiments, unused subcarriers are also included on both sides of the frequency-domain data. For example, as Figure 5A shown, two unused subcarriers are on one side of the first subcarrier group 501, while two unused subcarriers are on the other side of the third subcarrier group 502.

[0041] Since n is even, when transmitting one layer of data, the data carried by the four subcarriers included in each subcarrier group can be spread by one or more spreading codes (e.g., [1, -1, -1, 1]). For example, when the data carried in the subcarrier group is D, the data modulated onto the four subcarriers in the subcarrier group is D, -D, -D, and D. The frequency-domain data of each symbol is processed by the inverse Fourier transform 504 to obtain the time-domain data.

[0042] Embodiment 3

[0043] Figure 5B Shows another example of spreading one layer of data according to one or more embodiments of the present technology. The data is modulated onto two subcarrier groups in the frequency domain. Here, each subcarrier group includes the same number of 2×n subcarriers: n = 2. The subcarrier groups are separated by one or more unused subcarriers (i.e., subcarriers that do not carry data). For example, the first subcarrier group 511 and the second subcarrier group 512 are separated by five unused subcarriers (e.g., five subcarriers carrying 0).

[0044] In some embodiments, unused subcarriers are also included on both sides of the frequency-domain data. For example, as Figure 5BAs shown, two unused subcarriers are on one side of the first subcarrier group 511, while two unused subcarriers are on the other side of the third subcarrier group 512.

[0045] In this embodiment, the data modulated onto different subcarrier groups can be spread using different codes. For example, since n is even, the data carried by the four subcarriers included in each subcarrier group can be spread by one or more spreading codes (such as [1, -1, -1, 1] and [1, -1, 1, -1]). For example, if the data carried by the subcarrier group 511 is D1, then the data modulated onto the four subcarriers in the subcarrier group 511' becomes D1, -D1, -D1, and D1. If the data carried by the subcarrier group 512 is D2, then the data modulated onto the four subcarriers in the subcarrier group 512' becomes D2, -D2, D2, and -D2. The frequency-domain data of each symbol is processed by the inverse Fourier transform 504 to obtain the time-domain data.

[0046] Embodiment 4

[0047] Figure 5C Shows another example of spreading one layer of data according to one or more embodiments of the present technology. The data is modulated onto two subcarrier groups in the frequency domain. Here, the subcarrier groups include different numbers of subcarriers. The first subcarrier group 521 includes four subcarriers (n = 2, even), while the second subcarrier group 522 includes two subcarriers (n = 1, odd). The subcarrier groups are separated by one or more unused subcarriers (i.e., subcarriers that do not carry data). For example, the first subcarrier group 521 and the second subcarrier group 522 are separated by five unused subcarriers (such as five subcarriers carrying 0).

[0048] In some embodiments, unused subcarriers are also included on both sides of the frequency-domain data. For example, as Figure 5C shown, two unused subcarriers are on one side of the first subcarrier group 521, while two unused subcarriers are on the other side of the third subcarrier group 522.

[0049] In this embodiment, data modulated onto different sub - carrier groups can be spread using different codes. For example, for the first sub - carrier group 521, since n is even, the data carried by this group can be spread by one or more spreading codes (such as [1, - 1, - 1, 1]). For example, if the data carried in sub - carrier group 521 is D1, then the data modulated onto the four sub - carriers in sub - carrier group 521' becomes D1, - D1, - D1, and D1. For the second sub - carrier group 522, n is odd. So the data carried by this group can be spread by the spreading code [1, - 1]. For example, if the data carried in sub - carrier group 522 is D2, then the data modulated onto the two sub - carriers in sub - carrier group 522' becomes D2, - D2. The frequency - domain data of each symbol is processed by an inverse Fourier transform 504 to obtain time - domain data.

[0050] Embodiment 5

[0051] Figure 6 Shows an example of spreading multi - layer data according to one or more embodiments of the present technology. The data is modulated onto two sub - carrier groups in the frequency domain. Here, each sub - carrier group includes the same number of 2×n sub - carriers: n = 2. The sub - carrier groups are separated by one or more unused sub - carriers (i.e., sub - carriers that do not carry data). For example, the first sub - carrier group 601 and the second sub - carrier group 602 are separated by five unused sub - carriers (e.g., five sub - carriers carrying 0).

[0052] In some embodiments, unused sub - carriers are also included on both sides of the frequency - domain data. For example, as Figure 6 shown, two unused sub - carriers are on one side of the first sub - carrier group 601, while two unused sub - carriers are on the other side of the third sub - carrier group 602.

[0053] Since n is an even number, when transmitting multi-layer data, the data carried by the four subcarriers included in each subcarrier group can be spread by one or more spreading codes, such as [1, -1, -1, 1], [1, -1, 1, -1], and [1, 1, -1, -1]. For example, the first-layer data is spread using the code [1, -1, -1, 1], the second-layer data is spread using the code [1, -1, 1, -1], and the third-layer data is spread using the code [1, 1, -1, -1], thereby achieving orthogonality via code-division multiple access. For example, when the data carried in the subcarrier group is D1 for the first layer, D2 for the second layer, and D3 for the third layer, the data modulated onto the four subcarriers in the subcarrier group is [D1, -D1, -D1, D1], [D2, -D2, D2, -D2], and [D3, D3, -D3, -D3]. The data transmitted on the four subcarriers after multiplexing the three layers of data is [(D1 + D2 + D3), (-D1 - D2 + D3), (-D1 + D2 - D3), (D1 - D2 - D3)]. The frequency-domain data of each symbol is processed by an inverse Fourier transform 604 to obtain time-domain data.

[0054] Example 6

[0055] Figure 7 An example of spreading multi-layer data according to one or more embodiments of the present technology. In this embodiment, the data to be transmitted is downlink data including three layers / groups in a multi-carrier system. The data is modulated onto two subcarrier groups in the frequency domain. Here, each subcarrier group includes the same number of 2×n subcarriers: n = 2. The subcarrier groups are separated by one or more unused subcarriers (i.e., subcarriers that do not carry data).

[0056] The data to be transmitted in the first layer is [a1, a2], the data to be transmitted in the second layer is [b1, b2], and the data to be transmitted in the third layer is [c1, c2]. The first-layer data is spread using the code [1, -1, -1, 1] to obtain spread data [a1, -a1, -a1, a1; a2, -a2, -a2, a2]. The second-layer data is spread using the code [1, -1, 1, -1] to obtain spread data [b1, -b1, b1, -b1; b2, -b2, b2, -b2]. The third-layer data is spread using the code [1, 1, -1, -1] to obtain spread data [c1, c1, -c1, -c1; c2, c2, -c2, -c2].

[0057] Then, code-division multiplexing is performed on the spread data of the third layer to determine the data modulated onto the subcarriers in the two subcarrier groups 701, 702. The frequency-domain data of each symbol is processed by an inverse Fourier transform to obtain time-domain data.

[0058] Figure 8 FIG. 800 shows an example of a wireless communication system 800 in which techniques according to one or more embodiments of the present technology may be applied. The wireless communication system 800 may include one or more base stations (BSs) 805a, 805b, one or more wireless devices 810a, 810b, 810c, 810d, and a core network 825. The base stations 805a, 805b may provide wireless services to the wireless devices 810a, 810b, 810c, and 810d in one or more wireless sectors. In some embodiments, the base stations 805a, 805b include directional antennas to generate two or more directional beams to provide wireless coverage in different sectors.

[0059] The core network 825 may communicate with one or more base stations 805a, 805b. The core network 825 provides connectivity to other wireless communication systems and wired communication systems. The core network may include one or more service subscription databases to store information related to the subscribed wireless devices 810a, 810b, 810c, and 810d. The first base station 805a may provide wireless services based on a first radio access technology, while the second base station 805b may provide wireless services based on a second radio access technology. Depending on the deployment scenario, the base stations 805a and 805b may be quasi-co-located or may be installed separately on site. The wireless devices 810a, 810b, 810c, and 810d may support multiple different radio access technologies.

[0060] Figure 9 is a block diagram representation of a part of a radio station. A radio station 905 such as a base station or a wireless device (or UE) may include processor electronics 910 such as a microprocessor implementing one or more of the wireless technologies presented in this document. The radio station 905 may include transceiver electronics 915 to transmit and / or receive wireless signals via one or more communication interfaces such as an antenna 920. The radio station 905 may include other communication interfaces for transmitting and receiving data. The radio station 905 may include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some embodiments, the processor electronics 910 may include at least a part of the transceiver electronics 915. In some embodiments, at least some of the disclosed techniques, modules, or functions are implemented using the radio station 905.

[0061] It should be understood that this document discloses techniques that may be embodied in a wireless communication system to increase spectrum utilization by transmitting data using dispersed narrow spectrum without introducing interference between adjacent frequency sub-bands.

[0062] In an example aspect, a wireless communication method includes: determining a set of time-domain symbols by applying an inverse Fourier transform to a set of processed data modulated on a plurality of subcarrier groups. Each subcarrier group includes an even number of subcarriers, and adjacent subcarrier groups are separated by one or more unused subcarriers. The set of processed data is determined by applying a first spreading code to data carried in a subcarrier group having 2×m subcarriers when m is a positive odd number, and applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers when n is a positive even number. The method further includes transmitting the set of time-domain symbols.

[0063] In some embodiments, each subcarrier group includes a different number of subcarriers. In some embodiments, the plurality of subcarrier groups include the same number of subcarriers. In some embodiments, the number of one or more unused subcarriers is greater than or equal to the number of subcarriers in any adjacent subcarrier group.

[0064] In some embodiments, the first spreading code includes [1, -1]. In some embodiments, the one or more spreading codes include at least one of [1, -1], [1, -1, -1, 1], [1, -1, 1, -1], or [1, 1, -1, -1]. In some embodiments, applying the one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers includes applying a spreading code of [1, -1] to uplink data carried in the subcarrier group. In some embodiments, applying the one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers includes applying at least one of the spreading codes [1, -1, -1, 1], [1, -1, 1, -1], or [1, 1, -1, -1] to downlink data carried in the subcarrier group.

[0065] In some embodiments, the data modulated onto the plurality of subcarrier groups includes a plurality of layers, and the set of processed data is determined by applying different spreading codes to different layers of the data to obtain a plurality of spread data sequences, and multiplexing the plurality of spread data sequences to obtain the set of processed data.

[0066] In some embodiments, for different subcarrier groups having 2×n subcarriers, the set of processed data is determined by applying different spreading codes to data carried in each subcarrier group.

[0067] In another exemplary aspect, a wireless communication method includes: receiving a set of time-domain symbols that carry a set of time-domain symbols of processed data modulated on one or more subcarrier groups. Each subcarrier group includes an even number of subcarriers. The set of processed data corresponds to the output of: when m is a positive odd number, applying a first spreading code to data carried in a subcarrier group having 2×m subcarriers, and when n is a positive even number, applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers. The method further includes demodulating the set of time-domain symbols to obtain the data.

[0068] In some embodiments, each subcarrier group includes a different number of subcarriers. In some embodiments, multiple subcarrier groups include the same number of subcarriers. In some embodiments, the number of one or more unused subcarriers is greater than or equal to the number of subcarriers in any adjacent subcarrier group.

[0069] In some embodiments, the first spreading code includes [1, -1]. In some embodiments, one or more spreading codes include at least one of [1, -1], [1, -1, -1, 1], [1, -1, 1, -1], or [1, 1, -1, -1]. In some embodiments, applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers includes applying the spreading code [1, -1] to uplink data carried in the subcarrier group. In some embodiments, applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers includes applying at least one of the spreading codes [1, -1, -1, 1], [1, -1, 1, -1], or [1, 1, -1, -1] to downlink data carried in the subcarrier group.

[0070] In some embodiments, the data modulated onto multiple subcarrier groups includes multiple layers. The set of processed data corresponds to the output of applying different spreading codes to different layers of data to obtain multiple spread data sequences and multiplexing the multiple spread data sequences to obtain the set of processed data.

[0071] In some embodiments, for different subcarrier groups having 2×n subcarriers, the set of processed data corresponds to the output of applying different spreading codes to data carried in each subcarrier group.

[0072] In another exemplary aspect, a communication device is disclosed. The device includes a processor configured to implement the method disclosed above.

[0073] In yet another exemplary aspect, a computer program product having code stored thereon is disclosed. When executed by a processor, the code causes the processor to implement the methods disclosed above.

[0074] The disclosed and other embodiments, modules, and functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or in a combination of one or more of them. The disclosed embodiments and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer-readable medium for execution by, or to control the operation of, a data processing apparatus. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter affecting a machine-readable propagated signal, or a combination of one or more of them. The term "data processing apparatus" encompasses all apparatus, devices, and machines for processing data, including, for example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, the apparatus can include code that creates an execution environment for the computer program under discussion, e.g., code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. The propagated signal is an artificially generated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, generated to encode information for transmission to an appropriate receiver apparatus.

[0075] A computer program (also referred to as a program, software, software application, script, or code) can be written in any form of programming language, including a compiled or interpreted language, and can be deployed in any form, including deployment 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. The program can be stored in a part of a file that holds other programs or data, such as one or more scripts stored in a markup language document, in a single file dedicated to the program under discussion, or in multiple cooperating files, such as files that store one or more modules, subroutines, or portions of code. A computer program can be deployed to execute on one computer or on multiple computers located at one site or distributed across multiple sites and interconnected by a communication network.

[0076] The processes and logical flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logical flows can also be performed by, and the apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0077] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any type of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to, one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data, to receive data from or transfer data to the mass storage devices, or both. However, a computer need not have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0078] Although this document contains many details, these details should not be construed as limitations on the scope of the claimed invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented separately in multiple embodiments or in any suitable sub-combination. Moreover, although the features may be described above as acting in certain combinations and even initially claimed as such, in some cases, one or more features from a claimed combination can be deleted from the combination, and the claimed combination can be directed to a sub-combination or a variant of a sub-combination.

[0079] Similarly, although operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in a sequential order, or that all illustrated operations be performed, to achieve desirable 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.

[0080] Only a few embodiments and examples are described, and other embodiments, improvements, and variations can be made based on what is described and shown in this disclosure.

Claims

1. A wireless communication method, comprising: Determining a set of time-domain symbols by applying an inverse Fourier transform to a set of processed data modulated on a plurality of subcarrier groups, wherein each subcarrier group contains an even number of subcarriers, and adjacent subcarrier groups are separated by a plurality of unused subcarriers, the number of the plurality of unused subcarriers being greater than or equal to the number of subcarriers in any one of the adjacent subcarrier groups, and wherein the set of processed data is determined by: Applying a first spreading code to data carried in a subcarrier group having 2×m subcarriers, where m is a positive odd number, and Applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers, where n is a positive even number; and Transmitting the set of time-domain symbols.

2. The method according to claim 1, wherein, Each subcarrier group contains a different number of subcarriers.

3. The method according to claim 1, wherein The plurality of subcarrier groups contain the same number of subcarriers.

4. The method according to any one of claims 1 to 3, wherein The first spreading code includes [1, -1].

5. The method according to any one of claims 1 to 3, wherein, The one or more spreading codes include at least one of [1, -1], [1, -1, -1, 1], [1, -1, 1, -1] or [1, 1, -1, -1].

6. The method according to any one of claims 1 to 3, wherein applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers includes applying a spreading code of [1, -1] to uplink data carried in the subcarrier group.

7. The method according to any one of claims 1 to 3, wherein Applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers includes applying at least one of the spreading codes [1, -1, -1, 1], [1, -1, 1, -1] or [1, 1, -1, -1] to downlink data carried in the subcarrier group.

8. The method according to any one of claims 1 to 3, wherein, The data modulated onto the plurality of subcarrier groups includes a plurality of layers, and wherein the set of processed data is determined by: Applying different spreading codes to different layers of the data to obtain a plurality of spread data sequences; and Multiplexing the plurality of spread data sequences to obtain the set of processed data.

9. The method according to any one of claims 1 to 3, wherein, The set of processed data is determined by: For different subcarrier groups having 2×n subcarriers, applying different spreading codes to data carried in each subcarrier group.

10. A wireless communication method, the method comprising: Receiving a set of time-domain symbols, the set of time-domain symbols carrying a set of processed data modulated on one or more subcarrier groups, wherein each subcarrier group contains an even number of subcarriers, and adjacent subcarrier groups are separated by a plurality of unused subcarriers, the number of the plurality of unused subcarriers being greater than or equal to the number of subcarriers in any one of the adjacent subcarrier groups, and wherein the set of processed data corresponds to the output of: Applying a first spreading code to data carried in a subcarrier group having 2×m subcarriers, where m is a positive odd number, and Applying one or more spreading codes to data carried in a subcarrier group having 2×n subcarriers, where n is a positive even number; and Demodulate the set of time-domain symbols to obtain the data.

11. The method according to claim 10, wherein, Each subcarrier group contains a different number of subcarriers.

12. The method according to claim 10, wherein The plurality of subcarrier groups contain the same number of subcarriers.

13. The method according to any one of claims 10 to 12, wherein The first spreading code includes [1, -1].

14. The method according to any one of claims 10 to 12, wherein, The one or more spreading codes include at least one of [1, -1], [1, -1, -1, 1], [1, -1, 1, -1], or [1, 1, -1, -1].

15. The method according to any one of claims 10 to 12, wherein, Applying the one or more spreading codes to the data carried in a subcarrier group having 2×n subcarriers includes applying the spreading code [1, -1] to the uplink data carried in the subcarrier group.

16. The method according to any one of claims 10 to 12, wherein, Applying the one or more spreading codes to the data carried in a subcarrier group having 2×n subcarriers includes applying at least one of the spreading codes [1, -1, -1, 1], [1, -1, 1, -1], or [1, 1, -1, -1] to the downlink data carried in the subcarrier group.

17. The method according to any one of claims 10 to 12, wherein, The data modulated onto the plurality of subcarrier groups includes a plurality of layers, and wherein the set of processed data corresponds to the output of: Applying different spreading codes to different layers of the data to obtain a plurality of spread data sequences; and Multiplexing the plurality of spread data sequences to obtain the set of processed data.

18. The method according to any one of claims 10 to 12, wherein The set of processed data is determined by: For different subcarrier groups having 2×n subcarriers, applying different spreading codes to the data carried in each subcarrier group.

19. A communication device, comprising a processor configured to implement the method according to any one of claims 1 to 18.

20. A computer-readable storage medium having code stored thereon, which when executed by a processor causes the processor to implement the method according to any one of claims 1 to 18.

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