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EP-3429148-B1 - PULSE SHAPING METHOD AND TRANSMITTER

EP3429148B1EP 3429148 B1EP3429148 B1EP 3429148B1EP-3429148-B1

Inventors

  • ZHAO, Zhao
  • WANG, QI
  • LONG, Yi
  • GUO, ZHIHENG
  • CHENG, XINGQING
  • QIN, Long

Dates

Publication Date
20260506
Application Date
20170331

Claims (7)

  1. A transmitter (10), comprising: an inverse Fourier transform, IFT, module (103), a pulse shaping filter (102), a pulse shaping controller (101), and a parallel-to-serial conversion, P/S, module (104), wherein the inverse Fourier transform module (103) is configured to: perform inverse Fourier transform on a baseband modulation signal obtained after serial-to-parallel conversion, and output a transformed signal to the pulse shaping filter (102); the pulse shaping controller (101) is configured to: receive pulse configuration signaling, generate, based on the pulse configuration signaling, a pulse parameter corresponding to a to-be-configured pulse, and output the pulse parameter to the pulse shaping filter (102); the pulse shaping filter (102) is configured to: perform pulse shaping processing on the output signal of the inverse Fourier transform module (103) based on the pulse parameter, and output a processed signal to the P/S module (104), wherein the pulse parameter comprises all or a part of a preset parameter set, and the preset parameter set comprises a first flag bit Flag head , a second flag bit Flag tail , a first value N 1 , a second value N 2 , a shape P type of the to-be-configured pulse, and a length K of the to-be-configured pulse relative to a single OFDM symbol period; and the first flag bit Flag head is used to indicate whether pulse shaping is performed on an OFDM symbol header, the second flag bit Flag tail is used to indicate whether pulse shaping is performed on a OFDM symbol tail, the first value N 1 is used to indicate a quantity of sampling points that are in a single OFDM symbol, on which pulse shaping is to be performed, and whose magnitude weights are not equal to 1, and the second value N 2 is used to indicate a quantity of sampling points that are outside the single OFDM symbol and on which pulse shaping is to be performed, wherein a quantity of 2N 2 overlapping sampling points between a tail part of a previous OFDM symbol and the single OFDM symbol are added to a header part of the single OFDM symbol; and the P/S module (104) is configured to output the processed signal of the pulse shaping filter (102) in serial.
  2. The transmitter according to claim 1, wherein when the second flag bit Flag tail is equal to a second enable value, the pulse shaping filter comprises an adding module and a windowing module; the adding module (1021) is configured to: add a cyclic suffix of a second length to an OFDM symbol corresponding to the output signal of the inverse Fourier transform module, and output the OFDM symbol with the added cyclic suffix to the windowing module (1023); and the windowing module (1023) is configured to: for a tail part of the OFDM symbol output by the adding module (1021), perform windowing processing on the OFDM symbol at N sampling points of the tail part by using a latter part of a preset windowing function, and output the OFDM symbol obtained after the windowing processing, wherein N is a positive integer.
  3. The transmitter according to claim 2, wherein when the first flag bit Flag head is equal to a first enable value, the pulse shaping filter further comprises a calculation module; the adding module is configured to: add a cyclic prefix of a first length to the OFDM symbol corresponding to the output signal of the inverse Fourier transform module, and output the OFDM symbol with the added cyclic prefix to the windowing module; the windowing module is configured to: for the header part of the OFDM symbol output by the adding module, perform windowing processing on the OFDM symbol at M sampling points of the header part by using a former part of the preset windowing function, and output, to the calculation module, the OFDM symbol obtained after the windowing processing, wherein M is a positive integer; and the calculation module is configured to: add X sampling points of the tail part of the previous OFDM symbol and the OFDM symbol at X sampling points of the header part of the OFDM symbol obtained after the windowing processing, and output the OFDM symbol obtained after the adding, wherein X is a positive integer.
  4. The transmitter (10) according to claim 2 or 3, further comprising: a storage module (1027), configured to store, in a storage medium, Y sampling points of the tail part of the OFDM symbol obtained after the windowing processing, wherein Y is a positive integer.
  5. A pulse shaping method, applied to a transmit end, and comprising: receiving, by a pulse shaping controller, pulse configuration signaling, and generating, based on the pulse configuration signaling, a pulse parameter corresponding to a to-be-configured pulse; performing, by a pulse shaping filter, pulse shaping processing on a communication signal based on the pulse parameter and outputting a processed signal to a parallel-to-serial conversion, P/S, module, wherein the pulse parameter comprises all or a part of a preset parameter set, and the preset parameter set comprises a first flag bit Flag head , a second flag bit Flag tail , a first value N 1 , a second value N 2 , a shape P type of the to-be-configured pulse, and a length K of the to-be-configured pulse relative to a single OFDM symbol period; and the first flag bit Flag head is used to indicate whether pulse shaping is performed on a OFDM symbol header, the second flag bit Flag tail is used to indicate whether pulse shaping is performed on a OFDM symbol tail, the first value N 1 is used to indicate a quantity of sampling points that are in a single OFDM symbol, on which pulse shaping is to be performed, and whose magnitude weights are not equal to 1, and the second value N 2 is used to indicate a quantity of sampling points that are outside the single OFDM symbol and on which pulse shaping is to be performed, wherein a quantity of 2N 2 overlapping sampling points between a tail part of a previous OFDM symbol and the single OFDM symbol are added to a header part of the single OFDM symbol; and outputting, by the P/S module, the processed signal of the pulse shaping filter in serial.
  6. A computer program comprising instructions to cause the device of claim 1 to execute the steps of the method of claim 5.
  7. A computer-readable storage medium having stored thereon the computer program of claim 6.

Description

TECHNICAL FIELD This application relates to the communications field, and in particular, to a pulse shaping method, a transmitter, a receiver, and a system. BACKGROUND An orthogonal frequency division multiplexing (OFDM) system is a most widely applied communications system in recent years, for example, a Long Term Evolution (LTE) system. Compared with the LTE communications system, a next-generation communications system not only needs to be improved in performance, but also needs to support a new service type through a new air interface design. In addition to a conventional mobile broadband (MBB) service, the next-generation communications system further needs to support machine-to-machine (M2M) communication, man-computer communication (MCC), and other diversified new services such as ultra-reliable and low latency communications (URLLC) and massive machine type communications (MMTC). A new air interface technology includes technologies in a plurality of dimensions such as coding, a waveform, multiple access, and a frame structure. A waveform technology is a key to flexibly supporting a plurality of services, and is very important for a new air interface of a 5G system. An orthogonal frequency division multiplexing (OFDM) technology based on a cyclic prefix (CP), that is, CP-OFDM, has a good anti-multipath interference capability and has a good compatibility with various MIMO technologies. An existing OFDM system usually uses the CP-OFDM as a specific solution for a multi-carrier waveform. However, in the CP-OFDM system, a rectangular window is fixedly used for windowing processing. This has obvious defects in suppressing indicators such as an adjacent channel leakage ratio (ACLR) and out-of-band (OOB) power leakage, and leads to an undiversified pulse shape. Therefore, the CP-OFDM system cannot flexibly support a plurality of communication scenarios. Related technology with adaptive pulse shaping filters is disclosed in US 2015/0372843 A1, US 2008/0118012 A1 and US 2012/230449 A1. SUMMARY This application provides pulse shaping methods, a transmitter and a receiver to implement flexible configuration for pulse shaping, and support different communication scenarios. The invention is hereby defined by the transmitter of claim 1, and the pulse shaping method of claim 5. According to the transmitter provided in this application, an upper layer on a transmitter side may send, to the pulse shaping controller based on different communication scenarios, pulse configuration signaling carrying different pulse parameters, to control the pulse shaping filter to configure different pulse shapes for the different communication scenarios, thereby flexibly accommodating the different communication scenarios. According to the receiver provided in this application, which does not form part of the claimed invention, an upper layer on a receiver side may send, to the pulse shaping controller based on different communication scenarios, pulse configuration signaling carrying different pulse parameters, to control the pulse shaping filter in the receiver to configure different pulse shapes for the different communication scenarios, thereby flexibly accommodating the different communication scenarios. BRIEF DESCRIPTION OF DRAWINGS To describe technical solutions in this application more clearly, the following briefly describes the accompanying drawings required for describing the embodiments. FIG 1A is a schematic diagram of an application scenario according to this application;FIG 1B is a schematic diagram of another application scenario according to this application;FIG 1C is a schematic diagram of still another application scenario according to this application;FIG 2 is a schematic architectural diagram of a transmitter according to this application;FIG 3 is a schematic diagram of transmission of two adjacent symbols according to this application;FIG 4 is a schematic block diagram of implementing a transmitter according to this application;FIG 5 is another schematic block diagram of implementing a transmitter according to this application;FIG 6 is a schematic architectural diagram of a receiver according to this application;FIG. 7 is a schematic block diagram of implementing a receiver according to this application;FIG. 8 is another schematic block diagram of implementing a receiver according to this application;FIG. 9 is a schematic flowchart of a pulse shaping method at a transmit end according to this application; andFIG. 10 is a schematic flowchart of a pulse shaping method at a receive end according to this application. DESCRIPTION OF EMBODIMENTS Terms used in the embodiments of this application are merely used to explain the specific embodiments of this application, but are not intended to limit this application. First, several possible application scenarios related to this application are first described. As shown in FIG. 1A to FIG. 1C, different communication scenarios have different requirements for a signal-to-noi