WO2018058678A1

WO2018058678A1 - Signal processing method and device

Info

Publication number: WO2018058678A1
Application number: PCT/CN2016/101382
Authority: WO
Inventors: 铁晓磊; 花梦
Original assignee: 华为技术有限公司
Priority date: 2016-09-30
Filing date: 2016-09-30
Publication date: 2018-04-05

Abstract

Disclosed are a signal processing method and device. A receiver device comprises a radio frequency (RF) system and a baseband processor, wherein the RF system is used for receiving an orthogonal frequency division multiplexing (OFDM) signal from an air interface, and the baseband processor is used for receiving the OFDM signal from the RF system. Window interception is performed on time domain sample points of the OFDM signal according to M fast Fourier transform (FFT) windows corresponding to a second subcarrier interval to obtain N2 time domain sample points in each FFT window; an N2-point FFT calculation operation is performed on the N2 time domain sample points in each FFT window to obtain N2 frequency domain sample points corresponding to the FFT window; a frequency domain symbol of a second OFDM symbol is obtained from the N2 frequency domain sample points according to a frequency domain resource location allocated to the second OFDM symbol; a frequency domain symbol of a first OFDM symbol is obtained from N1 frequency domain sample points in the M FFT windows according to a frequency domain resource location allocated to the first OFDM symbol. Embodiments of the present invention can reduce the complexity of processing signals by the receiver device.

Description

Signal processing method and device

Technical field

The present invention relates to the field of communications technologies, and in particular, to a signal processing method and device.

Background technique

At present, subcarriers with multiple subcarrier spacings can be simultaneously supported in the same system bandwidth. For example, the uplink of the narrowband Internet of Things (NB-IoT) system supports both subcarrier spacings of 3.75 kHz and 15 kHz. In this way, the base station can simultaneously receive signals of two subcarrier spacings of 3.75 kHz and 15 kHz.

For a base station, it is necessary to simultaneously process signals of a plurality of different subcarrier intervals. For example, with a Long Term Evolution (LTE) signal with a subcarrier spacing of 15 kHz and an NB-IoT signal with a 3.75 kHz as an example, the base station needs to follow the NB-IoT signal at the same sampling rate of 1.92 MHz. The FT-IoT signal is filtered by the Fast Fourier Transformation (FFT) window, and the NB-IoT signal is subjected to 512-point FFT operation. For the LTE signal, the base station needs to filter the LTE signal according to the FFT window of the LTE signal. And perform a 128-point FFT operation on the LTE signal. It can be seen that for different subcarrier spacing signals, the base station needs to separately filter for each signal by using different FFT windows, and perform FFT calculation, which makes the base station process signals have higher complexity.

Summary of the invention

The embodiment of the invention discloses a signal processing method and device, which can reduce the complexity of processing signals by the receiving end device.

A first aspect of the embodiments of the present invention discloses a receiving end device, including: a radio frequency RF system and a baseband processor, where the baseband processor is connected to the RF system, where

The RF system is configured to receive an Orthogonal Frequency Division Multiplexing (OFDM) signal from an air interface, where the OFDM signal includes a first OFDM symbol of a first subcarrier spacing and a second OFDM symbol of an M second subcarrier spacing, a time domain length of the first OFDM symbol and M of the second OFDM The time domain length of the symbol is the same, the first subcarrier spacing is 1/M of the second subcarrier spacing, and M is a positive integer;

The baseband processor is configured to receive the OFDM signal from the RF system, and perform window on a time domain sample of the OFDM signal according to M fast Fourier transform FFT windows corresponding to the second subcarrier spacing Intercepting, obtaining N2 time domain samples in each of the FFT windows; performing an N2 point FFT calculation operation on N2 time domain samples in each of the FFT windows to obtain N2 frequencies corresponding to the FFT window a domain sample; obtaining a frequency domain symbol of the second OFDM symbol from the N2 frequency domain samples according to a frequency domain resource location allocated for the second OFDM symbol; according to the first OFDM symbol allocated The frequency domain resource location acquires frequency domain symbols of the first OFDM symbol from N1 frequency domain samples in the M FFT windows, where the N1 frequency domain samples are for the M×N2 After the frequency domain samples are processed, N1 and N2 are positive integers, and N1=N2×M.

The OFDM symbol of the first subcarrier spacing and the OFDM symbol of the second subcarrier spacing are multiplexed by a Frequency Division Multiplexing (FDM) method. The frequency domain resource location allocated for the second OFDM symbol is different from the frequency domain resource location allocated for the first OFDM symbol. The frequency domain resource location allocated for the second OFDM symbol can be understood as the position of the subcarrier allocated to the second OFDM symbol for carrying the frequency domain symbol in the system bandwidth. The frequency domain resource location allocated for the first OFDM symbol can be understood as the position of the subcarrier allocated to the first OFDM symbol for carrying the frequency domain symbol in the system bandwidth, for example, the system bandwidth is from 10 MHz to 20 MHz. The second OFDM symbol occupies 10 MHz to 15 MHz band resources, and the first OFDM symbol occupies 15 MHz to 20 MHz.

It can be seen that, on the receiving end side, the baseband processor can multiplex the FFT processing result corresponding to the second OFDM symbol, and calculate the FFT processing result corresponding to the first OFDM symbol, that is, adopt a set of FFT window for the OFDM symbols with multiple subcarrier spacings. The processing is performed instead of performing FFT calculations according to the respective FFT windows, thereby reducing the complexity of processing signals by the receiving device.

In a possible implementation manner, when performing window interception on a time domain sample of the OFDM signal, the baseband processor is further configured to:

Time domain samples of length N _cp are removed from the OFDM signal prior to each of the FFT windows.

In a possible implementation manner, the first OFDM symbol of the first subcarrier spacing and the second OFDM symbol of the M second subcarrier spacing coexist in a preset frequency band, where the first OFDM symbol and The second OFDM symbol is from a different source device. The preset frequency band is a frequency band that is transmitted by the system to the first OFDM symbol of the first subcarrier interval and the second OFDM symbol of the M second subcarrier spacing.

In a possible implementation manner, the time at which the receiving end device starts receiving the first OFDM symbol is T1, and the receiving end device starts receiving the time points of the consecutive M second OFDM symbols. For T2, the absolute value of the difference between the T1 and the T2 is less than a preset time threshold. The preset time threshold may be a length of time of the cyclic prefix. In other words, the second OFDM symbol of consecutive M second subcarrier spacings and the first OFDM symbol of one first subcarrier spacing are aligned in time.

A second aspect of the embodiments of the present invention discloses a transmitting end device, including: a radio frequency RF system and a baseband processor, where the baseband processor is connected to the RF system, where

The baseband processor is used to:

Acquiring N1 time domain samples corresponding to the first orthogonal frequency division multiplexing OFDM symbol of the first subcarrier interval, where the N1 time domain samples are inverse fast Fourier transform IFFT calculation on the input frequency domain signal The time domain samples of the cyclic prefix are not inserted, N1 is a positive integer; the N1 time domain samples are equally divided into M segments, each segment is labeled S _i , and each segment S _i Including N2 time domain samples, where i={0, 1, 2, 3, ..., M-1}, M and N2 are positive integers, N1=N2×M; for the S _i , in the N _cp time domain samples are inserted before N 2 time domain samples of S _i , wherein the N _cp time domain samples are N 2 time domain samples of S _{{(i-1) mod M}} The last N _cp time domain samples, N _cp is a positive integer; the sequentially arranged (N _CP ×M+N1) time domain samples are determined as the first OFDM symbol of the first subcarrier interval, and Transmitting the first OFDM symbol to the RF system;

The RF system is configured to send the first OFDM symbol to a receiving end device.

It can be seen that, on the transmitting end side, after the baseband processor performs segmentation and insertion of samples on the acquired time domain samples, the first OFDM symbol of the first subcarrier interval is generated and transmitted, so that the receiving end device receives In the signal, each segment of the first OFDM symbol and the M second OFDM symbols are respectively The upper end is aligned, so that the receiving end device can multiplex the FFT processing result corresponding to the second OFDM symbol, and further calculate the FFT processing result corresponding to the first OFDM symbol, thereby reducing the complexity of processing the signal by the receiving end device.

In a possible implementation manner, the first OFDM symbol of the first subcarrier interval and the second OFDM symbol of the second subcarrier interval coexist in a preset frequency band, and a time domain length of the first first OFDM symbol The length of the time domain of the M second OFDM symbols is the same, and the second subcarrier spacing is M times the interval of the first subcarrier. The first OFDM symbol and the second OFDM symbol may be from the same source device or from different source devices.

In a possible implementation manner, a length of a cyclic prefix of the second OFDM symbol is the N _cp .

In a possible implementation manner, the time when the second M OFDM symbol of the second subcarrier interval reaches the receiving end device and the time when the first OFDM symbol of the first subcarrier interval reaches the receiving end device The absolute value of the difference is less than the preset time threshold;

For each of the S _i , an absolute value of a difference between a time when the S _i arrives at the receiving end device and a time when the acyclic prefix portion of the second OFDM symbol reaches the receiving end device is less than a preset time threshold. The preset time threshold may be a length of time of the cyclic prefix.

The absolute value of the difference between the time when the second OFDM symbol of the second M carrier interval reaches the receiving end device and the time when the first OFDM symbol of the first subcarrier interval reaches the receiving end device is smaller than The preset time threshold, that is, the second OFDM symbol of consecutive M second subcarrier intervals and the first OFDM symbol of one first subcarrier interval are aligned in time.

A third aspect of the embodiments of the present invention discloses a signal processing method, including:

Receiving an Orthogonal Frequency Division Multiplexing (OFDM) signal, the OFDM signal comprising a first OFDM symbol of a first subcarrier spacing and a second OFDM symbol of the M second subcarrier spacing, a time domain of the first OFDM symbol The length is the same as the time domain length of the M second OFDM symbols, the first subcarrier spacing is 1/M of the second subcarrier spacing, and M is a positive integer; corresponding to the second subcarrier spacing M fast Fourier transform FFT windows for window clipping of time domain samples of the OFDM signal to obtain N2 time domain samples in each of the FFT windows; for each of the FFT windows N2 time domain samples perform an N2 point FFT calculation operation, and obtain N2 frequency domain samples corresponding to the FFT window; according to the frequency domain resource locations allocated for the second OFDM symbol, the N2 frequency domain samples Obtaining a frequency domain symbol of the second OFDM symbol; acquiring the first one from the N1 frequency domain samples in the M FFT windows according to a frequency domain resource location allocated for the first OFDM symbol a frequency domain symbol of an OFDM symbol, wherein the N1 frequency domain samples are obtained by processing the M×N2 frequency domain samples, and N1 and N2 are positive integers, and N1=N2×M.

In a possible implementation, when performing window interception on a time domain sample of the OFDM signal, the method further includes:

In a possible implementation manner, the first OFDM symbol of the first subcarrier spacing and the second OFDM symbol of the M second subcarrier spacing coexist in a preset frequency band, the first OFDM symbol and the The second OFDM symbol is from a different source device.

In a possible implementation, the time point at which the first OFDM symbol is received is T1, and the time point at which the consecutive M second OFDM symbols are received is T2, where the T1 and the T2 are The absolute value of the difference is less than the preset time threshold.

A fourth aspect of the embodiments of the present invention discloses a signal processing method, including:

Acquiring N1 time domain samples corresponding to the first orthogonal frequency division multiplexing OFDM symbol of the first subcarrier interval, where the N1 time domain samples are inverse fast Fourier transform IFFT calculation on the input frequency domain signal The time domain samples of the cyclic prefix are not inserted, N1 is a positive integer; the N1 time domain samples are equally divided into M segments, each segment is labeled S _i , and each segment S _i Including N2 time domain samples, where i={0, 1, 2, 3, ..., M-1}, M and N2 are positive integers, N1=N2×M; for the S _i , in the N _cp time domain samples are inserted before N 2 time domain samples of S _i , wherein the N _cp time domain samples are N 2 time domain samples of S _{(i-1) _{mod M}} The last N _cp time domain samples, N _cp is a positive integer; the sequentially arranged (N _CP ×M+N1) time domain samples are determined as the first OFDM symbol of the first subcarrier interval, and sent The first OFDM symbol.

It can be seen that, on the transmitting end side, the baseband processor can perform segmentation, insertion of samples, and the like on the acquired time domain samples, and then generate and transmit the first OFDM symbol of the first subcarrier spacing. In this way, in the signal received by the receiving end device, each segment of the first OFDM symbol is temporally aligned with the M second OFDM symbols, respectively, so that the receiving end device can multiplex the FFT processing corresponding to the second OFDM symbol. As a result, the FFT processing result corresponding to the first OFDM symbol is further calculated, thereby reducing the complexity of processing the signal by the receiving end device.

In a possible implementation manner, the first OFDM symbol of the first subcarrier spacing and the second OFDM symbol of the second subcarrier spacing coexist in a preset frequency band, and a time domain length of the first OFDM symbol is The M second OFDM symbols have the same time domain length, and the second subcarrier spacing is M times the first subcarrier spacing.

In a possible implementation, the length of the cyclic prefix of the second OFDM symbol is the N _cp .

In a possible implementation manner, the time when the second M OFDM symbol of the second M carrier interval reaches the receiving end device and the time when the first OFDM symbol of the first subcarrier interval reaches the receiving end device The absolute value of the difference is less than the preset time threshold;

For each of the S _i , an absolute value of a difference between a time when the S _i arrives at the receiving end device and a time when the acyclic prefix portion of the second OFDM symbol reaches the receiving end device is less than a preset time threshold.

The fifth aspect of the embodiment of the present invention discloses a baseband processor in a receiving end device or a receiving end device, where the baseband processor in the receiving end device or the receiving end device includes any third aspect of the embodiment of the present invention. A functional unit of some or all of the steps of a method. Wherein, the baseband processor in the receiving end device or the receiving end device can reduce the complexity of processing signals when performing some or all of the steps of any of the methods of the third aspect. A sixth aspect of the embodiments of the present invention discloses a baseband processor in a transmitting end device or a transmitting end device, where the baseband processor in the transmitting end device or the transmitting end device includes any of the fourth aspect of the embodiments of the present invention. A functional unit of some or all of the steps of a method. Among them, the When the baseband processor in the sending end device or the transmitting end device performs some or all of the steps of any of the fourth methods, the obtained time domain samples can be segmented, inserted, and the like, and the first subcarrier spacing is generated. The first OFDM symbol is transmitted and transmitted.

A seventh aspect of the embodiments of the present invention discloses a computer storage medium storing a program, the program specifically comprising instructions for performing some or all of the steps of any of the third aspects of the embodiments of the present invention.

The eighth aspect of the embodiments of the present invention discloses a computer storage medium, where the computer storage medium stores a program, and the program specifically includes instructions for performing some or all of the steps of any of the fourth aspects of the embodiments of the present invention.

In some possible implementations, for a receiving end device, the radio frequency RF system includes an antenna, a radio frequency front end RFFE, and a radio frequency chip RFIC, the antenna is connected to the RFFE, and the RFFE is connected to the RFIC; The antenna is configured to receive the OFDM signal from an air interface; the RFFE is configured to couple the OFDM signal received by the antenna to the RFIC; and the RFIC is configured to perform a down conversion process on the OFDM signal. Wherein, the down conversion processing is specifically demodulation.

In some possible implementations, for a transmitting device, the radio frequency RF system includes an antenna, a radio frequency front end RFFE, and a radio frequency chip RFIC, the antenna is connected to the RFFE, and the RFFE is connected to the RFIC; The RFIC is configured to perform an up-conversion process on the first OFDM symbol; the RFFE is configured to couple the first OFDM symbol generated by up-converting the RFIC to the antenna; the antenna is used to send The first OFDM symbol. Wherein, the up-conversion processing is specifically modulation.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings to be used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without paying for creative labor.

1 is a schematic diagram of a network architecture of a wireless communication system according to an embodiment of the present invention;

1A is a schematic diagram of a transmission and reception structure of an OFDM system according to an embodiment of the present invention;

1B is a schematic structural diagram of a device at a transmitting end according to an embodiment of the present invention;

2 is a schematic flow chart of a signal processing method according to an embodiment of the present invention;

2A is a schematic diagram showing a symbol structure of a first OFDM symbol of a first subcarrier interval according to an embodiment of the present disclosure;

3 is a schematic flow chart of another signal processing method according to an embodiment of the present invention;

FIG. 3A is a schematic diagram of a symbol structure of coexistence of OFDM symbols with different subcarrier spacings according to an embodiment of the present invention; FIG.

FIG. 3B is a schematic diagram of an iterative process of FFT calculation according to an embodiment of the present invention; FIG.

4 is a schematic structural diagram of a baseband processor in a transmitting end device or a transmitting end device according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a baseband processor in a receiving end device or a receiving end device according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The terms "comprising" and "comprising" and variations of the invention are intended to be in the meaning For example, a process, method, system, product, or device that comprises a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units not listed, or alternatively Other steps or units inherent to these processes, methods, products or equipment.

The embodiment of the invention discloses a signal processing method and device, which can reduce the complexity of processing signals by the receiving end device. The details are described below separately.

In order to better understand the embodiments of the present invention, a wireless communication disclosed in the embodiment of the present invention is first described below. A schematic diagram of the network architecture of the letter system is described.

Please refer to FIG. 1. FIG. 1 is a schematic diagram of a network architecture of a wireless communication system according to an embodiment of the present invention. As shown in FIG. 1, the wireless communication system includes a receiving end device 010 and a plurality of transmitting end devices (such as a transmitting end device 021, a transmitting end device 022, a transmitting end device 023, ... a transmitting end device 028), and those skilled in the art. It can be understood that although only eight transmitting devices are shown in FIG. 1, they do not constitute a limitation of the embodiment of the present invention, and may include more transmitting devices than those illustrated.

The receiving end device 010 may be one or more of a base station or an access point or a base station controller, and the receiving end device 010 is configured to provide communication services for the at least one wireless terminal, where the sending end device may be a wireless terminal, where The wireless terminal may include, but is not limited to, a smart phone, a notebook computer, a personal computer (PC), a personal digital assistant (PDA), a mobile internet device (MID), a smart wearable device (eg, Smart watches, smart bracelets and other electronic devices.

The wireless communication system may include, but is not limited to, a narrowband Internet of Things (NB-IoT) system and a future fifth generation mobile communication technology (5th-Generation, 5G) system, in which the wireless communication system can simultaneously Supporting subcarriers with multiple subcarrier spacings, where subcarrier spacing is the interval between center frequency points between two adjacent subcarriers, and for Long Term Evolution (LTE) signals, subcarrier spacing At 15 kHz, for NB-IOT, the subcarrier spacing is 3.75 kHz. Among them: the uplink of the NB-IoT system supports both subcarriers with 3.75 kHz and 15 kHz subcarrier spacing; in the 5G system, different subcarrier spacing signals need to be deployed in the same frequency band to support a wider range of scenarios and richer. Applications. Generally, the uplink and downlink system bandwidths of the NB-IoT system are both 200 kHz. In the downlink, the NB-IoT system uses OFDM (Orthogonal Frequency Division Multiplexing) technology, and the NB-IoT system uses SC. -FDMA (Single-Carrier Frequency Division Multiplexing Access) technology. In addition, 5G systems still use OFDM technology.

It should be noted that, since the SC-FDMA signal transmission is actually a Discrete Fourier Transform (DFT) process on the time domain signal, and then mapped to a subcarrier corresponding to the frequency resource, the modulation mode of the OFDM is adopted. Signal modulation is sent out. Therefore, in the present invention The terms in the embodiment are collectively described using terms such as "OFDM symbol". However, the present invention is equally applicable to the case of SC-FDMA signal transmission.

Referring to FIG. 1A, FIG. 1A is a schematic diagram of a transmitting and receiving structure of an OFDM system according to an embodiment of the present invention. As shown in FIG. 1A, on the transmitting end side, the transmitting end device performs subcarrier mapping on the input symbol sequence {x _n } and performs serial-to-parallel conversion, and then performs inverse discrete Fourier transform through N points (Inverse Discrete Fourier Transform). , IDFT)/Inverse Fast Fourier Transformation (IFFT) calculation, after inserting the Cyclic Prefix (CP) and doing D/A conversion (DAC), the OFDM time domain signal is obtained, and then the RF is obtained. The (Radio Frequency, RF) section transmits the OFDM time domain signal over the multipath channel. On the receiving end side: after receiving the OFDM time domain signal through the RF part, the receiving end device performs A/D conversion (ADC), and removes the cyclic prefix CP according to the DFT/Fast Fourier Transformation (FFT) window. And performing DFT/FFT calculation operation, after extracting each modulation symbol on the corresponding subcarrier, that is, subcarrier demapping, and then performing demodulation and decoding operation, the original bit sequence {x _n } can be recovered.

At present, the transmission and reception structures of an OFDM system are usually implemented by using an IFFT processing module and an FFT processing module. Assuming that the subcarrier spacing of the OFDM system is Δf Hz and the sampling rate used is SHz, the FFT points of the IFFT processing module used for the OFDM system are used. For S/Δf, define S/Δf=X. For a transmitting end device using OFDM modulation, the symbol sequence to be transmitted is serial-to-parallel converted (optionally, a zero-padding operation can also be performed), and the symbol after serial-to-output is added after several zero points, each X The symbols are a group, and the IFFT processing is performed to obtain X points, and the output is subjected to parallel-to-serial conversion, that is, corresponding to X symbol samples in the time domain. In order to resist the interference caused by multipath, after the IFFT processing, the transmitting device inserts a cyclic prefix of several samples (assumed to be Y) before the X symbol samples, and the cyclic prefix is actually X. The last Y samples of the symbol sample are repeated one before the X symbol samples. Therefore, the final OFDM symbol corresponds to (X+Y) sample points in the time domain, and the time corresponding to the OFDM symbol is ((X+Y)×Ts) second time length, where Ts is the reciprocal of the sampling rate SHz . It should be noted that the time corresponding to the cyclic prefix (X×Ts) should be greater than a certain threshold ThresholdCP, which is the length of the multipath delay spread of the channel between the transmitting and receiving parties (the transmitting device and the receiving device). The communication environment is determined by the location.

Referring to FIG. 1B, FIG. 1B is a schematic structural diagram of a transmitting end device according to an embodiment of the present invention. The transmitting end device 020 shown in FIG. 1B may be any one of the transmitting end devices shown in FIG. . As shown in FIG. 1B, the transmitting device 020 includes a radio frequency (RF) system 21 and a baseband processor 22, and the baseband processor 22 is connected to the RF system 21, wherein the RF system 21 can include At least one of an antenna, a radio frequency front end (RFFE), or a radio frequency integrated circuit (RFIC) (not shown). The antenna is coupled to the RFFE, the RFFE is coupled to the RFIC, the RFIC is for modulating or demodulating an RF signal, and the RFFE is for receiving or transmitting the RF signal through the antenna. The signal transmitted from the baseband processor 22 is modulated by the RFIC and coupled to the antenna for transmission (transmitting channel) via the RFFE, or the RFFE couples the air interface signal received by the antenna to the RFIC, and the air interface signal is demodulated by the RFIC and sent to the baseband for processing at the back end. The device 22 is processed by a communication protocol (receiving channel). The baseband processor 22 mainly processes the baseband signal and can process various communication protocols such as 2/3/4/5G (Generation). The baseband processor 22 can include a plurality of logic gate cells or transistors and can be integrated on a substrate to form a chip by an integrated circuit fabrication process. The structure of the receiving device is also similar to the structure of FIG. 1B and will not be described again.

In the embodiment of the present invention, for the receiving end device, it is sometimes necessary to receive and process signals of two different subcarrier intervals at the same time. Especially in the uplink, the receiving device may need to process signals of multiple subcarrier spacings simultaneously, for example, in a 5G system. In view of this, in the embodiment of the present invention, the baseband processor included in the sending end device can perform corresponding processing on the signal to be sent (refer to the description in the following embodiments), and the receiving end device receives the processed by the sending end device. After the signal, the complexity of the processed signal can be reduced when processing the processed signal.

It should be noted that the structure of the transmitting end device or the receiving end device in FIG. 1B is only a preferred implementation manner in the embodiment of the present invention, and the structure of the receiving end device and the structure of the transmitting end device in the embodiment of the present invention. Including but not limited to the above structure, as long as the structure of the receiving end device and the structure of the transmitting end device capable of realizing the signal processing method in the present invention are within the scope of protection and coverage of the present invention.

Please refer to FIG. 2. FIG. 2 is a schematic flowchart diagram of a signal processing method according to an embodiment of the present invention. The signal processing method is applied to the transmitting device shown in FIG. 1B, and the signal processing method is described below from the baseband processor side in the transmitting device. As shown in FIG. 2, the signal processing method may include the following steps:

201. The baseband processor acquires N1 time domain samples corresponding to the first orthogonal frequency division multiplexing OFDM symbol of the first subcarrier spacing.

The N1 time domain samples are time domain samples in which the cyclic prefix is not inserted after the inverse fast Fourier transform IFFT calculation on the input frequency domain signal, and N1 is a positive integer.

Orthogonal Frequency Division Multiplexing (OFDM), which is one of multi-carrier modulation schemes, distributes high-speed data streams into a number of parallel low-speed subchannels for transmission by serial-to-parallel conversion.

In the embodiment of the present invention, when the transmitting end device needs to send the first orthogonal frequency division multiplexing OFDM symbol of the first subcarrier spacing, the baseband processor in the transmitting end device may first obtain an inverse fast fasting on the input frequency domain signal. The time domain samples of the cyclic prefix are not inserted after the ENERGY transform IFFT calculation, and further processing is performed to generate the first OFDM symbol.

202. The baseband processor divides the N1 time domain samples into M segments.

In the embodiment of the present invention, each segment is labeled as S _i , and each segment S _i includes N2 time domain samples, i={0, 1, 2, 3, ..., M-1}, M and N2. All are positive integers, N1=N2×M; optionally, the value of i can be i={1, 2, 3..., M}. In order to better describe the method of the present invention, the value i of i={0, 1, 2, 3, ..., M-1} is taken as an example for description.

The baseband processor may divide the N1 time domain samples into M segments according to a preset rule, and the preset rule is designed according to a specific M value, that is, according to the first subcarrier spacing and the second subcarrier. The relationship of the intervals is determined.

Without loss of generality, here the first subcarrier spacing is 3.75 kHz and the second subcarrier spacing is 15 kHz. The second subcarrier spacing is four times the first subcarrier spacing, assuming a 3.75 kHz OFDM symbol. Before inserting the CP, at a certain sampling rate, corresponding to 8192 time domain samples (ie, N1=8192), and an OFDM symbol with a 15 kHz subcarrier spacing, corresponding to 2048 time domain samples before the insertion of the CP (ie, N2= 2048). When the transmitting end device transmits the OFDM symbol of the first subcarrier spacing (subcarrier spacing of 3.75 kHz), the 8192 time domain samples are equally divided into four segments, which are respectively denoted as S ₀ , S ₁ , S ₂ and S. ₃ : As an example, before segmentation, the time domain samples of a 3.75 kHz OFDM symbol are denoted as x(0), x(1), ..., x(8191), then the four segments after segmentation The number of time domain samples contained in the segment are: S ₀ : {x(0), x(1), ..., x(2047)}, S ₁ : {x(2048), x(2049), ..., x(4095)}, S ₂ :{x(4096), x(4097),...,x(6143)} and S ₃ :{x(6144),x(6145),...,x(8191) }.

It should be noted that it is not excluded to use other preset rules. As long as the sending and receiving dual-issues perform the corresponding FFT or IFFT operations according to the preset rules, the correct reception of data can be ensured.

203, a baseband processor for each S _i, N _cp inserted time-domain samples prior to the N2 in the time domain samples of S _i.

The N _cp time domain samples are the last N _cp time domain samples of the N 2 time domain samples of S _{{(i-1) mod M}} , and N _cp is a positive integer. Specifically, N _cp is greater than A positive integer that presets the threshold. The size of N _cp depends on the communication environment. The longer the multipath delay spread in the communication environment, the larger the N _cp is, so as to reduce the intersymbol interference caused by the multipath delay extension, and then the length of N _cp cannot be too long. Otherwise, Air interface overhead will increase. Therefore, the length of the CP should be determined by the communication environment to which the system belongs, and both the transceiver and the dual-issue perform OFDM modulation and demodulation according to a preset value or a pre-agreed N _cp length.

For example, suppose M=4, i=0, then S _{(0-1)mod M} =S ₃ , which can be understood as S ₀ , insert N ₂ of S ₃ before N 2 time domain samples of S ₀ The last N _cp time domain samples of time domain samples; assuming M=4, i=1, then S _{(1-1) mod M} =S ₀ , which can be understood as S ₁ , at S ₁ The last N _cp time domain samples of N2 time domain samples of S ₀ are inserted before N2 time domain samples; and if M=4, i=2, then S _(2-1) _{mod M} =S ₁ , That is, it can be understood that for S ₂ , the last N _cp time domain samples of the N 2 time domain samples of S ₁ are inserted before the N 2 time domain samples of S ₂ ; assuming M=4, i=3, then S _{(3-1) mod M} = S ₂ , that is, it can be understood that for S ₃ , the last N _cp time domain samples of the N ₂ time domain samples of S ₂ are inserted before the N 2 time domain samples of S ₃ .

204. The baseband processor determines the sequentially aligned (N _CP ×M+N1) time domain samples as the first OFDM symbol of the first subcarrier spacing, and transmits the first OFDM symbol to the radio frequency RF system.

Among them, the sequential arrangement means that (N _CP ×M+N1) time domain samples have a certain time domain order.

Referring to FIG. 2A, FIG. 2A is a schematic diagram showing the symbol structure of a first OFDM symbol of a first subcarrier interval according to an embodiment of the present invention. Where N1=8192, N2=2048, M=4, N _CP =256. Each small square shown in FIG. 2A represents 128 time domain samples, called a set of time domain samples, each of which carries information. The sender device obtains 8192 time domain samples as follows:

abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZA'B'C'D'E'F'G'H'I'J'K'L'.

The sending end device divides the above 8192 time domain samples into four segments according to a preset rule, namely S ₀ , S ₁ , S _{2 ,} and S ₃ , where S ₀ , S ₁ , S _{2 ,} and S ₃ are respectively Includes 16 sets of time domain samples, respectively: S ₀ ={abcdefghijklmnop}, S ₁ ={qrstuvwxyzABCDEF}, S ₂ ={GHIJKLMNOPQRSTUV},S ₃ ={WXYZA'B'C'D'E'F'G'H'I'J'K'L'}, each letter represents a time domain sample group. Further, for each segment S _i , the transmitting device inserts 256 time domain samples before 2048 time domain samples of S _i , specifically, for S ₀ , the transmitting device is at 2048 times of S ₀ . The last 256 time domain samples of the 2048 time domain samples of S ₃ are inserted before the domain sample, that is, the time domain samples corresponding to K'L' are inserted. Similarly, for S ₁ , the transmitting device inserts the last 256 time domain samples of the 2048 time domain samples of S ₀ before the 2048 time domain samples of S ₁ , that is, inserts the time domain samples corresponding to the op; for S _2, the transmission side apparatus is inserted into the last 256 time domain samples S 2048 time-domain samples of _a prior S 2048 time-domain samples _2, i.e., the insertion time domain samples EF corresponding to; for S ₃ The transmitting device inserts the last 256 time domain samples of the 2048 time domain samples of S ₂ before the 2048 time domain samples of S ₃ , that is, inserts the time domain samples corresponding to the UV.

After the above processing, the first OFDM symbols of the first subcarrier interval composed of (N _CP ×M+N1)=4×256+8192=9216 time domain samples are:

K'L'abcdefghijklmnopopqrstuvwxyzABCDEFEFGHIJKLMNOPQRSTUVU VWXYZA'B'C'D'E'F'G'H'I'J'K'L'.

In an optional implementation manner, the first OFDM symbol of the first subcarrier interval and the second OFDM symbol of the second subcarrier interval coexist in a preset frequency band, and a time domain length of the first OFDM symbol The length of the time domain of the M second OFDM symbols is the same, and the second subcarrier spacing is M times the interval of the first subcarrier. The first OFDM symbol and the second OFDM symbol may be from different source devices, or the first OFDM symbol and the second OFDM symbol may be from the same source device. The cyclic prefix of the second OFDM symbol has a length of N _cp .

As another optional implementation manner, a difference between a time when the second OFDM symbol of the second M subcarrier interval reaches the receiving end device and a time when the first OFDM symbol of the first subcarrier interval reaches the receiving end device The absolute value is less than the preset time threshold;

The absolute value of the difference between the time when the S _i arrives at the receiving device and the time when the acyclic prefix portion of the second OFDM symbol arrives at the receiving device for each S _i is less than a preset time threshold.

The preset time threshold may be a length of time of the cyclic prefix.

The absolute value of the difference between the time when the second OFDM symbol of the second M subcarrier interval reaches the receiving end device and the time when the first OFDM symbol of the first subcarrier interval reaches the receiving end device is less than a preset time threshold. In other words, the second OFDM symbol of consecutive M second subcarrier spacings and the first OFDM symbol of one first subcarrier spacing are aligned in time.

Specifically, the start symbol boundary of the second OFDM symbol of the consecutive M second subcarrier intervals is aligned with the start symbol boundary of the first OFDM symbol of the first subcarrier interval, and consecutive M The end symbol boundary of the second OFDM symbol of the second subcarrier spacing is temporally aligned with the end symbol boundary of the first OFDM symbol of a first subcarrier spacing.

For example, in uplink communication, time alignment is performed by letting different transmitting devices pass Timing Advance in advance, so that signals sent by different transmitting terminals are substantially aligned at the time of arrival of the receiving device or The time difference is within the preset range. The amount of time sent is related to the distance of the propagation path between the transmitting device and the receiving device, and the time difference is within the preset range, that is, the time difference between the signals sent by different transmitting devices and the receiving device reaches the length of the CP. In the range, since the OFDM signal removes the CP portion after reception and performs FFT processing, in this way, different subcarriers remain orthogonal.

In the method flow described in FIG. 2, on the transmitting end side, the baseband processor performs segmentation and time domain sample processing on the acquired time domain samples, and then generates a first OFDM symbol of the first subcarrier spacing. And transmitting, so that each segment of the first OFDM symbol is temporally aligned with the M second OFDM symbols, so that the receiving end device can multiplex the FFT corresponding to the second OFDM symbol. Processing the result, and calculating the FFT processing knot corresponding to the first OFDM symbol Therefore, the complexity of processing signals by the receiving device is reduced.

For a transmitting device, the radio frequency RF system includes an antenna, a radio frequency front end RFFE, and a radio frequency chip RFIC, the antenna is connected to the RFFE, and the RFFE is connected to the RFIC; the RFIC is used to The first OFDM symbol is subjected to up-conversion processing; the RFFE is configured to couple the first OFDM symbol generated by up-converting the RFIC to the antenna; and the antenna is configured to send the first OFDM symbol. Wherein, the up-conversion processing is specifically modulation.

Referring to FIG. 3, FIG. 3 is a schematic flowchart diagram of another signal processing method according to an embodiment of the present invention, where the signal processing method is applied to the receiving device shown in FIG. 1B. The signal processing method will be described below from the baseband processor side in the receiving device. As shown in FIG. 3, the signal processing method may include the following steps:

301. A baseband processor receives an orthogonal frequency division multiplexing OFDM signal.

In the embodiment of the present invention, the receiving end device may receive the orthogonal frequency division multiplexing OFDM signal from the RF system. The OFDM signal includes a first OFDM symbol of a first subcarrier spacing and a second OFDM symbol of the M second subcarrier spacing, a time domain length of one first OFDM symbol and a time domain of the M second OFDM symbols. The length is the same, the first subcarrier spacing is 1/M of the second subcarrier spacing, and M is a positive integer. The first OFDM symbol and the second OFDM symbol may be from the same source device or from different source devices. For better description, in the embodiment of the present invention, the first OFDM symbol and the second OFDM symbol sent by different sending end devices are taken as an example, that is, OFDM symbols with different subcarrier spacings coexist.

Without loss of generality, the OFDM symbol of the first subcarrier spacing and the OFDM symbol of the second subcarrier spacing are multiplexed by Frequency Division Multiplexing (FDM), and the first OFDM symbol of the first subcarrier spacing And the second OFDM symbols of the M second subcarrier spacings coexist in a preset frequency band.

The first OFDM symbol of the first subcarrier interval is processed by the transmitting end device according to the method described in FIG. 2, and then transmitted to the RF system, and sent by the RF system to the receiving end device.

In addition, the time point at which the first OFDM symbol is received is T1, and the time point at which the start of the M consecutive OFDM symbols is started is T2, and the absolute value of the difference between T1 and T2 is less than the preset time threshold. In other words, the second OFDM symbol of the consecutive M second subcarrier spacings and the first OFDM symbol of the first subcarrier spacing are aligned in time. For details, refer to the related description in FIG. Let me repeat.

Referring to FIG. 3A, FIG. 3A is a schematic diagram of a symbol structure of OFDM symbols coexisting with different subcarrier spacings according to an embodiment of the present invention, where the first OFDM symbol and the second OFDM symbol are from different transmitting devices. The first subcarrier spacing is 1/4 of the second subcarrier spacing, and the first OFDM symbol of the first subcarrier spacing is sent by the transmitting end device according to the method described in FIG. As shown in FIG. 3A, the OFDM signal includes a first OFDM symbol of a first subcarrier spacing and a second OFDM symbol of four consecutive second subcarrier spacings. The symbol boundary of the first OFDM symbol of one first subcarrier interval and the symbol boundary of the second OFDM symbol of consecutive four second subcarrier intervals are aligned in time. And, further, for each segment S _{i of the} first OFDM symbol, the segment S _{i is} respectively temporally aligned with the acyclic prefix portion of a certain second OFDM symbol, wherein the acyclic prefix portion refers to A valid time domain sample (that is, a time domain sample that carries useful information). Specifically, S ₀ and the acyclic prefix portion of the first second OFDM symbol are aligned in time, and the acyclic prefix portion of S ₁ and the second second OFDM symbol are aligned in time, and S ₂ and non-cyclic prefix portion of the second three OFDM symbols are aligned in time, S ₃ and the non-cyclic prefix portion of the four second OFDM symbols in time are aligned. It can be seen that each segment of the first OFDM symbol of the first subcarrier spacing includes a number of time domain samples that coincide with the number of time domain samples included in the second OFDM symbol of the second subcarrier spacing.

302. The baseband processor performs window clipping on the time domain samples of the OFDM signal according to the M fast Fourier transform FFT windows corresponding to the second subcarrier spacing, to obtain N2 time domain samples in each FFT window.

In the embodiment of the present invention, since the transmitting end device performs corresponding processing on the first OFDM symbol (that is, the processing method described in FIG. 2), the OFDM symbol for two different subcarrier spacings may be processed by using a set of FFT windows. .

As an optional implementation manner, when the baseband processor performs window clipping on the time domain samples of the OFDM signal according to the M fast Fourier transform FFT windows corresponding to the second subcarrier spacing, the baseband processor may also obtain the OFDM signal from the OFDM signal. The removal length is a time domain sample of N _cp . 303. The baseband processor performs an N2 point FFT calculation operation on the N2 time domain samples in each FFT window to obtain N2 frequency domain samples corresponding to the FFT window.

Generally, if the first subcarrier spacing is 1/M of the second subcarrier spacing, the number of FFT points that the first OFDM symbol needs to be calculated is M times the number of FFT points that the second OFDM symbol needs to calculate. However, in the embodiment of the present invention, in view of the corresponding processing of the first OFDM symbol by the transmitting device, so that a set of FFT windows can be used for processing, the baseband processor only needs N2 time domain samples in each FFT window. The point performs an N2 point FFT calculation operation, and N2 frequency domain samples can be obtained for each FFT window. The N2 frequency domain samples correspond to N2 subcarriers, wherein the N2 subcarriers are determined by dividing a system bandwidth according to a second subcarrier spacing, where the system bandwidth is a first OFDM provided by the system to the first subcarrier spacing. The symbol and the frequency band of the second OFDM symbol transmission of the M second subcarrier spacing.

304. The baseband processor acquires frequency domain symbols of the second OFDM symbol from the N2 frequency domain samples according to the frequency domain resource location allocated for the second OFDM symbol.

The frequency domain resource location allocated for the second OFDM symbol can be understood as the position of the subcarrier allocated to the second OFDM symbol for carrying the frequency domain symbol in the system bandwidth, for example, the system bandwidth is from 10 MHz to 20 MHz. Location, where the second OFDM symbol occupies 10 MHz to 15 MHz band resources.

Specifically, the baseband processor may determine, according to a frequency domain resource location allocated for the second OFDM symbol, a subcarrier used by the second OFDM symbol, and further, may determine, by using the N2 frequency domain samples, the second OFDM symbol. The frequency domain samples carried on the subcarriers are frequency domain symbols of the second OFDM symbol. Further, the baseband processor may demodulate and decode the frequency domain symbols of the second OFDM symbol to obtain information transmitted by the transmitting end device through the second OFDM symbol.

305. The baseband processor acquires frequency domain symbols of the first OFDM symbol from N1 frequency domain samples in the M FFT windows according to the frequency domain resource location allocated for the first OFDM symbol.

The frequency domain resource location allocated for the first OFDM symbol can be understood as the location of the subcarrier allocated for the frequency domain symbol in the system bandwidth allocated to the first OFDM symbol. For example, the system bandwidth is from 10 MHz to 20 MHz, and the first OFDM symbol occupies 15 MHz to 20 MHz.

The frequency domain resource location allocated for the first OFDM symbol is different from the frequency domain resource location allocated for the second OFDM symbol. Both N1 and N2 are positive integers. For example, the system bandwidth is from 10MHz To a position of 20 MHz, wherein the second OFDM symbol occupies 10 MHz to 15 MHz band resources, and the first OFDM symbol occupies 15 MHz to 20 MHz.

Specifically, after obtaining the N2 frequency domain samples corresponding to the M FFT windows, the baseband processor may iteratively combine the N2 frequency domain samples corresponding to the M FFT windows to obtain N1 frequency domain samples, N1. The frequency domain samples correspond to N1 subcarriers, wherein the N1 subcarriers are determined by dividing the system bandwidth according to the first subcarrier spacing. The baseband processor may determine the subcarrier used by the first OFDM symbol according to the frequency domain resource location allocated for the first OFDM symbol, and further, may determine the subcarrier used by the first OFDM symbol from the N1 frequency domain samples. The frequency domain sample carried on is the frequency domain symbol of the first OFDM symbol. Further, the baseband processor may demodulate and decode the frequency domain symbols of the first OFDM symbol to obtain information transmitted by the transmitting end device through the first OFDM symbol.

The frequency domain symbol may be all or part of the corresponding OFDM symbol in the frequency domain. For example, for the first OFDM symbol, its frequency domain symbol may be part of the first OFDM symbol in the frequency domain. For the second OFDM symbol, its frequency domain symbol may be all of the second OFDM symbol in the frequency domain.

Among them, N1 frequency domain samples are obtained by processing M×N2 frequency domain samples. In order to better describe the processing, the following two formulas are introduced:

Among them, the definition of DFT is as follows (1):

Where n=0,1,2,...N-1; k=0,1,2,...,N-1,x _(n) is a sequence, and X _k is a DFT result of x(n), The algorithm complexity of O(N ² ) is required, which obviously increases exponentially with the number of points calculated by DFT.

In order to simplify the computational complexity of DFT, an FFT algorithm is introduced, the principle of which is shown in the following formula (2):

Where S ₁ [k]=DFT{s ₁ [n]}, S ₂ [k]=DFT{s ₂ [n]}, s ₁ [n]=x(n) is an even-numbered sequence, s ₂ [n]=x(n) is an odd-numbered sequence,

Among them, FFT is a fast algorithm of DFT, and FFT is obtained by improving the algorithm of DFT according to the characteristics of odd, even, virtual and real of DFT.

According to the above formula (2), it can be seen that the DFT result X _{k of the} N point can be decomposed into further processing of the DFT results of the two N/2 points, that is, the even points of the x(n) respectively. The sequence of the sequence and the odd point is subjected to an N/2 point DFT operation, and the DFT result of the N point x(n) is calculated according to the above formula (1). Among them, in the FFT calculation, N is generally a power of 2, that is, N=2 ^γ .

By the above formula, the calculation of the N-point DFT for the sequence x(n), n=0, 1, 2, ..., N-1 can be calculated from two N/2-point DFTs of length N/2 sequences. It is obtained that each N/2 point DFT result of each N/2 sequence can be calculated by N/4 point DFT results of two N/4 sequences, thereby stepping through the sequence x (step by step) n), n = 0, 1, 2, ..., the value of N-1 is calculated to obtain the DFT result _{Xk of the} final N point.

It can be seen that with this iterative algorithm of FFT, the complexity of the algorithm is O(NlogN)=O(N×γ). If the DFT result is calculated according to formula (1), the algorithm of O(N ² ) is complicated. Degree, obviously this algorithm using FFT can reduce the complexity of DFT calculation.

In the embodiment of the present invention, specifically, the baseband processor may perform iterative processing on the N2 frequency domain samples corresponding to the M FFT windows according to the formula (2), and obtain N1 frequency domain samples.

In the embodiment of the present invention, since each segment S _i of the M segments of the OFDM symbol of the first subcarrier interval is aligned with the FFT window of a second subcarrier interval, a second set may be adopted. The FFT window of the subcarrier spacing processes the OFDM signal, and performs an N2 point FFT calculation operation only for N2 time domain samples in each FFT window, and obtains N2 frequency domain samples corresponding to the FFT window, and then from N2 frequencies. The frequency domain symbols of the second OFDM symbol are obtained in the domain sample, and the N2 frequency domain samples corresponding to the M FFT windows are iterated to obtain N1 frequency domain samples, and the N1 frequency domain samples are obtained. a frequency domain symbol of an OFDM symbol, and finally demodulating and decoding the frequency domain symbol of the second OFDM symbol and the frequency domain symbol of the first OFDM symbol, respectively, to obtain information transmitted on the second OFDM symbol and the first OFDM The information passed on the symbol. It can be seen that the entire process only performs one FFT calculation operation and two demodulation operations, without performing two FFT calculation operations and two demodulation operations, thereby reducing the complexity of processing signals.

In some possible implementations, for a receiving end device, the radio frequency RF system includes an antenna, a radio frequency front end RFFE, and a radio frequency chip RFIC, the antenna is connected to the RFFE, and the RFFE is connected to the RFIC; The antenna is configured to receive the OFDM signal from an air interface; the RFFE is configured to couple the OFDM signal received by the antenna to the RFIC; and the RFIC is configured to perform a down conversion process on the OFDM signal. Wherein, the down conversion processing is specifically demodulation. Further, the baseband processor receives the OFDM signal from the RF system

Please refer to FIG. 3B together. FIG. 3B is a schematic diagram of an iterative process of FFT calculation according to an embodiment of the present invention. Among them, the FFT calculation of 8 points is shown in FIG. 3B. If the DFT result is calculated according to formula (1), the algorithm complexity of O(8 ² )=O(64) is required. If the DFT result is calculated according to the iterative algorithm of formula (2) FFT, O(8×3) is required. ) = O(24) algorithm complexity, it can be seen that this algorithm using FFT can reduce the complexity of DFT calculation.

In the method flow described in FIG. 3, on the receiving end side, the baseband processor may multiplex the FFT processing result corresponding to the second OFDM symbol, and calculate the FFT processing result corresponding to the first OFDM symbol, that is, the interval of multiple subcarriers. The OFDM symbols are processed by a set of FFT windows instead of performing FFT calculations according to the respective FFT windows, thereby reducing the complexity of processing signals by the receiving device.

Referring to FIG. 4, FIG. 4 is a schematic structural diagram of a baseband processor in a transmitting end device or a transmitting end device according to an embodiment of the present invention, where the baseband processor 400 in the transmitting end device 400 or the transmitting end device is used. For details, refer to the description in FIG. 2, and details are not described herein again. As shown in FIG. 4, the baseband processor 400 in the source device 400 or the source device may include:

The obtaining unit 401 is configured to acquire N1 time domain samples corresponding to the first orthogonal frequency division multiplexing OFDM symbol of the first subcarrier interval, where the N1 time domain samples are inversely fast for the input frequency domain signal. The time domain sample of the cyclic prefix is not inserted after the Fourier transform IFFT calculation, and N1 is a positive integer;

The dividing unit 402 is configured to divide the N1 time domain samples into M segments, each segment is labeled as S _i , and each of the segments S _i includes N2 time domain samples, where i={0,1,2,3..., M-1}, M and N2 are positive integers, N1=N2×M;

Insertion unit 403 is configured for the S _i, N _cp inserted time-domain samples prior to the N2 of the time domain samples S _i, wherein the time domain samples N _cp point S _{{(i -1)} The last N _cp time domain samples of N2 time domain samples of _{mod M}} , N _cp is a positive integer;

The determining sending unit 404 is configured to determine the (N _CP ×M+N1) time domain samples arranged in order as the first OFDM symbol of the first subcarrier interval, and send the first OFDM symbol.

The first OFDM symbol of the first subcarrier interval and the second OFDM symbol of the second subcarrier interval coexist in a preset frequency band, and the time domain length of the first OFDM symbol and the M second OFDM symbols The length of the time domain is the same, and the second subcarrier spacing is M times the interval of the first subcarrier.

The length of the cyclic prefix of the second OFDM symbol is the N _cp .

The absolute value of the difference between the time when the second OFDM symbol of the second M carrier interval reaches the receiving end device and the time when the first OFDM symbol of the first subcarrier interval reaches the receiving end device is smaller than Preset time threshold;

In the baseband processor 400 in the transmitting device 400 or the transmitting device described in FIG. 4, on the transmitting end side, the acquired time domain samples may be segmented, inserted, and the like, and then generated. The first OFDM symbol of the subcarrier spacing is transmitted and transmitted, so that each segment of the first OFDM symbol is temporally aligned with the M second OFDM symbols, so that the receiving end device can be recovered. Using the FFT processing result corresponding to the second OFDM symbol, the FFT processing result corresponding to the first OFDM symbol is calculated, thereby reducing the complexity of processing the signal by the receiving end device.

Referring to FIG. 5, FIG. 5 is a schematic structural diagram of a baseband processor in a receiving end device or a receiving end device according to an embodiment of the present invention, where the baseband processor 500 in the receiving end device 500 or the receiving end device is used. For details, refer to the description in FIG. 3, and details are not described herein again. As shown in FIG. 5, the baseband processor 500 in the receiving end device 500 or the receiving end device may include:

The receiving unit 501 is configured to receive an Orthogonal Frequency Division Multiplexing (OFDM) signal, where the OFDM signal includes a first OFDM symbol of a first subcarrier spacing and a second OFDM symbol of the M second subcarrier spacing, one of the foregoing The time domain length of an OFDM symbol is the same as the time domain length of the M second OFDM symbols, and the first subcarrier spacing is 1/M of the second subcarrier spacing, and M is a positive integer;

The intercepting unit 502 is configured to perform window clipping on the time domain samples of the OFDM signal according to the M fast Fourier transform FFT windows corresponding to the second subcarrier spacing, to obtain N2 in each of the FFT windows. Time domain sample

The calculating unit 503 is configured to perform an N2 point FFT calculation operation on the N2 time domain samples in each of the FFT windows to obtain N2 frequency domain samples corresponding to the FFT window;

An obtaining unit 504, configured to acquire frequency domain symbols of the second OFDM symbol from the N2 frequency domain samples according to a frequency domain resource location allocated for the second OFDM symbol;

The acquiring unit 504 is further configured to acquire frequency domain symbols of the first OFDM symbol from N1 frequency domain samples in the M FFT windows according to the frequency domain resource location allocated for the first OFDM symbol. The N1 frequency domain samples are obtained by processing the M×N2 frequency domain samples, and N1 and N2 are positive integers, and N1=N2×M.

Optionally, the baseband processor 500 shown in FIG. 5 may further include:

The intercepting unit 502 is further configured to remove a time domain sample of length N _cp from the OFDM signal before performing window clipping on the time domain sample of the OFDM signal.

The first OFDM symbol of the first subcarrier spacing and the second OFDM symbol of the M second subcarrier spacing coexist in a preset frequency band, where the first OFDM symbol and the second OFDM symbol are from On different sender devices.

The time at which the receiving unit 501 starts receiving one of the first OFDM symbols is T1, and the time at which the receiving unit 501 starts receiving the consecutive M second OFDM symbols is T2, where the T1 and The absolute value of the difference of T2 is less than a preset time threshold. The preset time threshold may be the length of time of the cyclic prefix.

In the baseband processor 500 in the receiving end device 500 or the receiving end device described in FIG. 5, on the receiving end side, the FFT processing result corresponding to the second OFDM symbol may be multiplexed, and the FFT corresponding to the first OFDM symbol is calculated. The processing result is that a plurality of subcarrier spacing OFDM symbols are processed by using one set of FFT windows, instead of performing FFT calculation according to respective FFT windows, thereby reducing the complexity of processing signals by the receiving end device.

It should be noted that, for the foregoing various method embodiments, for the sake of simple description, they are all expressed as a series of action combinations, but those skilled in the art should understand that the present invention is not limited by the described action sequence. Because some steps may be performed in other orders or concurrently in accordance with the present application. In the following, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

In the above embodiments, the descriptions of the various embodiments are different, and the parts that are not described in detail in a certain embodiment can be referred to the related descriptions of other embodiments.

The steps in the method of the embodiment of the present invention may be sequentially adjusted, merged, and deleted according to actual needs. The units in the apparatus of the embodiment of the present invention may be combined, divided, and deleted according to actual needs.

A person skilled in the art may understand that all or part of the various steps of the foregoing embodiments may be performed by a program to instruct related hardware. The program may be stored in a computer readable storage medium, and the storage medium may include: Flash disk, Read-Only Memory (ROM), Random Access Memory (RAM), disk or optical disk.

The signal processing method and device provided by the embodiments of the present invention are described in detail. The principles and implementations of the present invention are described in the following. The description of the above embodiments is only used to help understand the present invention. The method and its core idea; at the same time, those skilled in the art, according to the idea of the present invention, there will be changes in the specific embodiments and application scope. In summary, the contents of this specification should not be construed as Limitations of the invention.

Claims

A receiving end device, comprising: a radio frequency RF system and a baseband processor, wherein the baseband processor is connected to the RF system, wherein

The RF system is configured to receive an Orthogonal Frequency Division Multiplexing (OFDM) signal from an air interface, where the OFDM signal includes a first OFDM symbol of a first subcarrier spacing and a second OFDM symbol of an M second subcarrier spacing, The time domain length of one of the first OFDM symbols is the same as the time domain length of the M second OFDM symbols, and the first subcarrier spacing is 1/M of the second subcarrier spacing, where M is a positive integer ;as well as

The baseband processor is used to:

Receiving the OFDM signal from the RF system;

And performing window clipping on the time domain samples of the OFDM signal according to the M fast Fourier transform FFT windows corresponding to the second subcarrier spacing, to obtain N2 time domain samples in each of the FFT windows;

Performing an N2 point FFT calculation operation on the N2 time domain samples in each of the FFT windows to obtain N2 frequency domain samples corresponding to the FFT window;

Obtaining frequency domain symbols of the second OFDM symbol from the N2 frequency domain samples according to a frequency domain resource location allocated for the second OFDM symbol;

Obtaining frequency domain symbols of the first OFDM symbol from N1 frequency domain samples in the M FFT windows according to a frequency domain resource location allocated for the first OFDM symbol, where the N1 frequency domains The sample is obtained by processing the M×N2 frequency domain samples, and N1 and N2 are positive integers, and N1=N2×M.
The receiving end device according to claim 1, wherein when performing window clipping on a time domain sample of the OFDM signal, the baseband processor is further configured to:

Time domain samples of length N cp are removed from the OFDM signal prior to each of the FFT windows.
The receiving end device according to claim 1 or 2, wherein the first OFDM symbol of the first subcarrier spacing and the second OFDM symbol of the M second subcarrier spacing coexist in a preset frequency band The first OFDM symbol and the second OFDM symbol are from different transmissions End device.
The receiving end device according to any one of claims 1 to 3, wherein the receiving end device starts receiving the first OFDM symbol at a time point T1, and the receiving end device starts to receive continuous The time point of the M second OFDM symbols is T2, and the absolute value of the difference between the T1 and the T2 is less than a preset time threshold.
A transmitting end device, comprising: a radio frequency RF system and a baseband processor, wherein the baseband processor is connected to the RF system, where

The baseband processor is used to:

Acquiring N1 time domain samples corresponding to the first orthogonal frequency division multiplexing OFDM symbol of the first subcarrier interval, where the N1 time domain samples are inverse fast Fourier transform IFFT calculation on the input frequency domain signal After the time domain sample of the cyclic prefix is not inserted, N1 is a positive integer;

Dividing the N1 time domain samples into M segments, each segment labeled S i , each of the segments S i including N2 time domain samples, where i={0,1 , 2, 3, ..., M-1}, M and N2 are positive integers, N1 = N2 × M;

For the S i, N cp inserted time-domain samples prior to the N2 of the time domain samples S i, wherein the time domain samples N cp point S {(i-1) mod M} The last N cp time domain samples of N2 time domain samples, N cp is a positive integer;

Arranging (N CP ×M+N1) time domain samples in order as the first OFDM symbol of the first subcarrier spacing, and transmitting the first OFDM symbol to the RF system;

The RF system is configured to send the first OFDM symbol to a receiving end device.
The transmitting end device according to claim 5, wherein the first OFDM symbol of the first subcarrier spacing and the second OFDM symbol of the second subcarrier spacing coexist in a preset frequency band, the first one The time domain length of the OFDM symbol is the same as the time domain length of the M second OFDM symbols, and the second subcarrier spacing is M times the first subcarrier spacing.
The transmitting device according to claim 6, wherein the length of the cyclic prefix of the second OFDM symbol is the N cp .
The transmitting device according to any one of claims 5 to 7, characterized in that: M consecutive The absolute value of the difference between the time when the second OFDM symbol of the second subcarrier interval reaches the receiving end device and the time when the first OFDM symbol of the first subcarrier interval reaches the receiving end device is less than a preset time threshold;

For each of the S i , an absolute value of a difference between a time when the S i arrives at the receiving end device and a time when the acyclic prefix portion of the second OFDM symbol reaches the receiving end device is less than a preset time threshold.
A signal processing method, comprising:

Receiving an Orthogonal Frequency Division Multiplexing (OFDM) signal, the OFDM signal comprising a first OFDM symbol of a first subcarrier spacing and a second OFDM symbol of the M second subcarrier spacing, a time domain of the first OFDM symbol The length is the same as the length of the time domain of the M second OFDM symbols, where the first subcarrier spacing is 1/M of the second subcarrier spacing, and M is a positive integer;

And performing window clipping on the time domain samples of the OFDM signal according to the M fast Fourier transform FFT windows corresponding to the second subcarrier spacing, to obtain N2 time domain samples in each of the FFT windows;

Performing an N2 point FFT calculation operation on the N2 time domain samples in each of the FFT windows to obtain N2 frequency domain samples corresponding to the FFT window;

Obtaining frequency domain symbols of the second OFDM symbol from the N2 frequency domain samples according to a frequency domain resource location allocated for the second OFDM symbol;

Obtaining frequency domain symbols of the first OFDM symbol from the N1 frequency domain samples in the M FFT windows according to a frequency domain resource location allocated for the first OFDM symbol, where the N1 The frequency domain samples are obtained by processing the M×N2 frequency domain samples, and N1 and N2 are positive integers, and N1=N2×M.
The method according to claim 9, wherein when the window is intercepted for the time domain sample of the OFDM signal, the method further includes:

Time domain samples of length N cp are removed from the OFDM signal prior to each of the FFT windows.
The method according to claim 9 or 10, wherein the first OFDM symbol of the first subcarrier spacing and the second OFDM symbol of the M second subcarrier spacing are at a preset frequency In-band coexistence, the first OFDM symbol and the second OFDM symbol are from different source devices.
The method according to any one of claims 9 to 11, wherein a time point at which one of the first OFDM symbols is started to be received is T1, and a time point at which the start of the M consecutive OFDM symbols is started is T2, the absolute value of the difference between the T1 and the T2 is less than a preset time threshold.
A signal processing method, comprising:

Acquiring N1 time domain samples corresponding to the first orthogonal frequency division multiplexing OFDM symbol of the first subcarrier interval, where the N1 time domain samples are inverse fast Fourier transform IFFT calculation on the input frequency domain signal After the time domain sample of the cyclic prefix is not inserted, N1 is a positive integer;

Dividing the N1 time domain samples into M segments, each segment labeled S i , each of the segments S i including N2 time domain samples, where i={0,1 , 2, 3, ..., M-1}, M and N2 are positive integers, N1 = N2 × M;

For the S i, N cp inserted time-domain samples prior to the N2 of the time domain samples S i, wherein the time domain samples N cp point S {(i-1) mod M} The last N cp time domain samples of N2 time domain samples, N cp is a positive integer;

The (N CP ×M+N1) time domain samples arranged in order are determined as the first OFDM symbol of the first subcarrier interval, and the first OFDM symbol is transmitted.
The method according to claim 13, wherein the first OFDM symbol of the first subcarrier spacing and the second OFDM symbol of the second subcarrier spacing coexist in a preset frequency band, the one first OFDM symbol The length of the time domain is the same as the length of the time domain of the M second OFDM symbols, and the second subcarrier spacing is M times the interval of the first subcarrier.
The method according to claim 14, wherein the length of the cyclic prefix of the second OFDM symbol is the N cp .
The method according to any one of claims 13 to 15, wherein the time at which the second M OFDM symbols of the second subcarrier interval arrive at the receiving end device and the interval of one of the first subcarrier intervals The absolute value of the difference of the time when an OFDM symbol arrives at the receiving end device is less than a preset time threshold;

For each of the S i , an absolute value of a difference between a time when the S i arrives at the receiving end device and a time when the acyclic prefix portion of the second OFDM symbol reaches the receiving end device is less than a preset time threshold.