Method for determining carrier center frequency and apparatus

Abstract

A method for determining a carrier center frequency in a wireless communications system and apparatus is provided. The method includes: determining, a carrier center frequency used by a base station and UE to communicate, according to a frequency band starting frequency, an absolute radio frequency channel number, a frequency band offset, and a relative radio frequency channel number. According to this application, a time for searching for a cell by a terminal can be reduced, power consumption of the terminal can be reduced, and a battery life can be extended.

Claims

1. A method for determining a carrier center frequency, applied to a communication apparatus, the method comprising: determining an uplink frequency band starting frequency, an uplink absolute radio frequency channel number, an uplink frequency band offset, and an uplink relative radio frequency channel number; and determining an uplink carrier center frequency F.sup.NB.sub.UL, wherein F.sup.NB.sub.UL satisfies the following relationship:
F.sup.NB.sub.UL=F.sub.UL_low+0.1*(N.sub.UL−N.sub.Offs-UL)+0.0025*(2M.sub.UL); wherein F.sub.UL_low is the uplink frequency band starting frequency, N.sub.UL is the uplink absolute radio frequency channel number, and N.sub.Offs-UL is the uplink frequency band offset; and wherein M.sub.UL is the uplink relative radio frequency channel number, M.sub.UL is one value in a set of values, and the set of values comprises: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 1, 2, 3, 4, 5, 6, 7, 8, 9.

2. The method according to claim 1, wherein determining the uplink carrier center frequency F.sup.NB.sub.UL comprising: determining F.sup.NB.sub.UL in a narrowband internet of things (NB-IOT) system.

3. The method according to claim 1, wherein determining the uplink carrier center frequency F.sup.NB.sub.UL comprising: determining F.sup.NB.sub.UL in one or more of the following modes: a standalone operation, an in-band operation, and a guard band operation.

4. The method according to claim 1, wherein the set of values further comprises: 0.

5. The method according to claim 1, wherein the set of values consists of: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

6. The method according to claim 1, wherein the communication apparatus is a terminal device.

7. An apparatus comprising: a processor and a non-transitory storage medium containing instructions that, when executed by the processor, cause the processor to: determine an uplink frequency band starting frequency, an uplink absolute radio frequency channel number, an uplink frequency band offset, and an uplink relative radio frequency channel number; and determine an uplink carrier center frequency F.sup.NB.sub.UL, wherein F.sup.NB.sub.UL satisfies the following relationship:
F.sup.NB.sub.UL=F.sub.UL_low+0.1*(N.sub.UL−N.sub.Offs-UL)+0.0025*(2M.sub.UL); wherein F.sub.UL_low is the uplink frequency band starting frequency, N.sub.UL is the uplink absolute radio frequency channel number, and N.sub.Offs-UL is the uplink frequency band offset; and wherein M.sub.UL is the uplink relative radio frequency channel number, M.sub.UL is one value in a set of values, and the set of values comprises: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 1, 2, 3, 4, 5, 6, 7, 8, 9.

8. The apparatus according to claim 7, wherein the instructions cause the processor to determine F.sup.NB.sub.UL in a narrowband internet of things (NB-IOT) system.

9. The apparatus according to claim 7, wherein the instructions cause the processor to determine F.sup.NB.sub.UL in one or more of the following modes: a standalone operation, an in-band operation, and a guard band operation.

10. The apparatus according to claim 7, wherein the set of values further comprises: 0.

11. The apparatus according to claim 8, wherein the set of values consists of: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

12. The apparatus according to claim 7, wherein the apparatus is a terminal.

13. A non-transitory computer readable medium comprising instructions that, when executed by a processor, cause the processor to execute at least the following operations: determining an uplink frequency band starting frequency, an uplink absolute radio frequency channel number, an uplink frequency band offset, and an uplink relative radio frequency channel number; and determining an uplink carrier center frequency F.sup.NB.sub.UL, wherein F.sup.NB.sub.UL satisfies the following relationship:
F.sup.NB.sub.UL=F.sub.UL_low+0.1*(N.sub.UL−N.sub.Offs-UL)+0.0025*(2M.sub.UL); wherein F.sub.UL_low is the uplink frequency band starting frequency, N.sub.UL is the uplink absolute radio frequency channel number, and N.sub.Offs-UL is the uplink frequency band offset; and wherein M.sub.UL is the uplink relative radio frequency channel number, M.sub.UL is one value in a set of values, and the set of values comprises: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 1, 2, 3, 4, 5, 6, 7, 8, 9.

14. The non-transitory computer readable medium according to claim 13, wherein the instructions cause the computer to determine F.sup.NB.sub.UL in a narrowband internet of things (NB-IOT) system.

15. The non-transitory computer readable medium according to claim 13, wherein the instructions cause the computer to determine F.sup.NB.sub.UL in one or more of the following modes: a standalone operation, an in-band operation, a guard band operation.

16. The non-transitory computer readable medium according to claim 13, wherein the set of values further comprises: 0.

17. The non-transitory computer readable medium according to claim 13, wherein the set of values consists of: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic diagram of a possible process for determining a carrier center frequency according to an embodiment of the present application;

(2) FIG. 2 is a schematic structural diagram of a base station according to an embodiment of the present application; and

(3) FIG. 3 is a schematic structural diagram of UE according to an embodiment of the present application.

DESCRIPTION OF EMBODIMENTS

(4) To make objectives, technical solutions, and advantages of embodiments of the present application clearer, the following clearly describes the technical solutions in the embodiments of the present application with reference to accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

(5) A network architecture and a service scenario described in the embodiments of the present application are used to describe the technical solutions in the embodiments of the present application more clearly, but are not intended to limit the technical solutions provided in the embodiments of the present application. A person of ordinary skill in the art may understand that, with evolution of the network architecture and appearance of a new service scenario, the technical solutions provided in the embodiments of the present application are also applicable to a similar technical problem.

(6) In this application, terms “network” and “system” are usually interchangeably used, but meanings thereof may be understood by a person of ordinary skill in the art. User equipment UE in this application may include various handheld devices, in-vehicle devices, wearable devices, or computing devices that have a wireless communications function, or other processing devices connected to a wireless modem, and user equipment (UE), a mobile station (MS), a terminal, terminal equipment that are in various forms, and the like. For ease of description, in this application, all the devices mentioned above are referred to as user equipment or UE. Abase station (BS) in the present application is an apparatus that is deployed in a radio access network and configured to provide a wireless communications function for the UE. The base station may include a macro base station, a micro base station, a relay node, an access point, and the like that are in various forms. In systems using different radio access technologies, a device having a base station function may have different names. For example, a device having a base station function is referred to as an evolved NodeB (eNB or eNodeB) in an LTE network, referred to as a NodeB in a 3rd Generation 3G network, or the like. For ease of description, in this application, all the foregoing apparatuses that provide a wireless communications function for the UE are referred to as a base station or a BS.

(7) FIG. 1 shows a method for determining a carrier center frequency according to an embodiment of the present application. The method is applied to an NB-IoT system. The following describes implementations of the present application in detail with reference to FIG. 1.

(8) S101. Determine a frequency band starting frequency, an absolute radio frequency channel number, and a frequency band offset.

(9) S102. Determine a carrier center frequency according to the frequency band starting frequency, the absolute radio frequency channel number, and the frequency band offset that are determined.

(10) Specifically, this embodiment of the present application provides several optional manners to determine a downlink carrier center frequency.

(11) A feasible manner of determining the downlink carrier center frequency is:
F.sup.NB.sub.DL=F.sup.NB.sub.DL_low+0.0025*(N.sup.NB.sub.DL−N.sup.NB.sub.Offs-DL);

(12) where F.sup.NB.sub.DL_low is a frequency band downlink frequency band starting frequency, a channel frequency raster is 0.0025 (MHz), N.sup.NB.sub.Offs-DL is a frequency band downlink offset, a value of N.sup.NB.sub.Offs-DL is 40 times that of a frequency band downlink offset N.sub.Offs-DL of an LTE system, N.sup.NB.sub.DL is a downlink absolute radio frequency channel number, a value range of N.sup.NB.sub.DL is [min*40, (max+1)*40−1], and [min, max] is a value range of an absolute radio frequency channel number N.sub.DL of the LTE system. N.sub.DL is an ARFCN of NB-IoT. Specifically, for a value of each parameter on the right side of the foregoing equation, refer to Table 1.

(13) TABLE-US-00001 TABLE 1 Parameter LTE (placeholder) NB-IoT (placeholder) Downlink F.sub.DL_low x Same as “x” N.sub.Offs-DL y y*40 Range of N.sub.DL [min, max] [min*40, (max + 1)*40 − 1] for each operating band

(14) Optionally, another feasible manner of determining the downlink carrier center frequency is:
F.sup.NB.sub.DL=F.sub.DL_low+0.1*(N.sub.DL−N.sub.Offs-DL)+0.0025*M.sub.DL;

(15) where M.sub.DL is a downlink relative radio frequency channel number, a value range of which includes any one in the following set: −20, −19, −18, −17, −16, −15, −14, −13, −12, −11, −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19. A channel frequency raster is 0.0025 (MHz).

(16) Optionally, another feasible manner of determining the downlink carrier center frequency is:
F.sup.NB.sub.DL=F.sup.NB.sub.DL_low+0.0025*((2*N.sup.NB.sub.DL+1)−N.sup.NB.sub.Offs-DL);

(17) where F.sup.NB.sub.DL_low is a frequency band downlink frequency band starting frequency, N.sup.NB.sub.Offs-DL is a frequency band downlink offset, a value of N.sup.NB.sub.Offs-DL is 40 times that of a frequency band downlink offset N.sup.NB.sub.Offs-DL of an LTE system, N.sup.NB.sub.DL is a downlink absolute radio frequency channel number, a value range of N.sup.NB.sub.DL is [min*20, (max+1)*20−1], and [min, max] is a value range of an absolute radio frequency channel number N.sub.DL of the LTE system. Specifically, for a value of each parameter on the right side of the foregoing equation, refer to Table 2.

(18) The downlink carrier center frequency F.sup.NB.sub.DL determined in this manner is a subset of center frequencies determined in the foregoing manner, including odd multiples of the channel frequency raster.

(19) TABLE-US-00002 TABLE 2 Parameter LTE (placeholder) NB-IoT (placeholder) Downlink F.sub.DL_low x Same as “x” N.sub.Offs-DL y y*40 Range of N.sub.DL [min, max] [min*20, (max + 1)*20 − 1] for each operating band

(20) Optionally, another feasible manner of determining the downlink carrier center frequency is:
F.sup.NB.sub.DL=F.sub.DL_low+0.1*(N.sub.DL−N.sub.Offs-DL)+0.0025*(2M.sub.DL+1);

(21) wherein M.sub.DL is a downlink relative radio frequency channel number, a value range of which includes any one in the following set: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

(22) The downlink carrier center frequency F.sup.NB.sub.DL determined in this manner is a subset of center frequencies determined in the foregoing manner, including odd multiples of the channel frequency raster or integer multiples of an LTE channel raster 0.1 MHz.

(23) This embodiment of the present application further provides several optional manners to determine an uplink carrier center frequency.

(24) A feasible manner of determining the uplink carrier center frequency is:
F.sup.NB.sub.UL=F.sup.NB.sub.UL_low+0.0025*(N.sup.NB.sub.UL−N.sup.NB.sub.Offs-UL);

(25) where F.sup.NB.sub.UL_low is a frequency band uplink frequency band starting frequency, N.sup.NB.sub.Offs-UL is a frequency band uplink offset, a value of N.sup.NB.sub.Offs-UL is 40 times that of a frequency band uplink offset N.sub.Offs-UL of an LTE system, N.sup.NB.sub.UL is an uplink absolute radio frequency channel number, a value range of N.sup.NB.sub.UL is [min*40, (max+1)*40−1], and [min, max] is a value range of an absolute radio frequency channel number N.sub.DL of the LTE system. N.sub.UL is an ARFCN of NB-IoT. Specifically, for a value of each parameter on the right side of the foregoing equation, refer to Table 3.

(26) TABLE-US-00003 TABLE 3 Parameter LTE (placeholder) NB-IoT (placeholder) Uplink F.sub.UL_low x Same as “x” N.sub.Offs-UL y y*40 Range of N.sub.UL [min, max] [min*40, (max + 1)*40 − 1] for each operating band

(27) Optionally, another feasible manner of determining the uplink carrier center frequency is:
F.sup.NB.sub.UL=F.sub.UL_low+0.1*(N.sub.UL−N.sub.Offs-UL)+0.0025*M.sub.UL;

(28) where M.sub.UL is an uplink relative radio frequency channel number, a value range of which includes any one in the following set: −20, −19, −18, −17, −16, −15, −14, −13, −12, −11, −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19.

(29) N.sub.DL and N.sub.UL are ARFCNs of NB-IoT, and their values are the same as those of N.sub.DL and N.sub.UL of an LTE system. Values of N.sup.NB.sub.Offs-DL and N.sub.Offs-UL are the same as those of N.sup.NB.sub.Offs-DL and N.sub.Offs-UL of the LTE system. M.sub.DL and M.sub.UL are newly-added parameters, may be defined as RRFCNs (relative RFCN), and their value ranges are shown above.

(30) Optionally, another feasible manner of determining the uplink carrier center frequency is:
F.sup.NB.sub.UL=F.sup.NB.sub.UL_low+0.0025*(2*N.sup.NB.sub.UL−N.sup.NB.sub.Offs-UL);

(31) where F.sup.NB.sub.UL_low is a frequency band uplink frequency band starting frequency, N.sup.NB.sub.Offs-UL is a frequency band uplink offset, a value of N.sup.NB.sub.Offs-UL is 40 times that of a frequency band uplink offset N.sub.Offs-UL of an LTE system, N.sup.NB.sub.UL is an uplink absolute radio frequency channel number, a value range of N.sup.NB.sub.UL is [min*20, (max+1)*20−1], and [min, max] is a value range of an absolute radio frequency channel number N.sub.UL of the LTE system. Specifically, for a value of each parameter on the right side of the foregoing equation, refer to Table 4.

(32) TABLE-US-00004 TABLE 4 Parameter LTE (placeholder) NB-IoT (placeholder) Uplink F.sub.UL_low x Same as “x” N.sub.Offs-UL y y*40 Range of N.sub.UL [min, max] [min*20, (max + 1)*20 − 1] for each operating band

(33) The uplink carrier center frequency F.sup.NB.sub.UL determined in this manner is a subset of center frequencies determined in the foregoing manner, including even multiples of the channel frequency raster.

(34) Optionally, another feasible manner of determining the uplink carrier center frequency is:
F.sup.NB.sub.UL=F.sub.UL_low+0.1*(N.sub.UL−N.sub.Offs-UL)+0.0025*(2M.sub.UL);

(35) where M.sub.UL is an uplink relative radio frequency channel number, a value range of which includes any one in the following set: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. The uplink carrier center frequency F.sup.NB.sub.UL determined in this manner is a subset of center frequencies determined in the foregoing manner, including even multiples of the channel frequency raster.

(36) FIG. 2 shows a possible schematic structural diagram of a base station in the foregoing embodiment.

(37) The base station includes a transmitter/receiver 1001, a controller/processor 1002, a memory 1003, and a communications unit 1004. The transmitter/receiver 1001 is configured to support information sending and receiving between the base station and the UE in the foregoing embodiment, and support radio communication between the UE and another UE. The controller/processor 1002 is configured to perform various functions for communicating with the UE. In an uplink, an uplink signal from the UE is received by an antenna, demodulated by the receiver 1001, and further processed by the controller/processor 1002 to restore service data and signaling information that are sent by the UE. In a downlink, service data and a signaling message are processed by the controller/processor 1002, and modulated by the transmitter 1001 to generate a downlink signal, and the downlink signal is transmitted to the UE by the antenna. The controller/processor 1002 is further configured to perform a processing process that includes the base station in this embodiment of the present application and/or another process of technology described in this application. The memory 1003 is configured to store program code and data of the base station. The communications unit 1004 is configured to support communication between the base station and another network entity. For example, the communications unit 1004 is configured to support communication between the base station and another communications network entity shown in FIG. 2, such as an MME, an SGW, and/or a PGW in a core network EPC.

(38) It may be understood that FIG. 3 merely shows a simplified design of the base station. In actual application, the base station may include any quantity of transmitters, receivers, processors, controllers, memories, communications units, and the like, and all base stations that can implement the present application fall within the protection scope of the present application.

(39) FIG. 3 shows a simplified schematic diagram of a possible design structure of UE in the foregoing embodiment. The UE includes a transmitter 1101, a receiver 1102, a controller/processor 1103, a memory 1104, and a modem processor 1105.

(40) The transmitter 1101 adjusts (for example, by means of analog conversion, filtering, amplification, and up-conversion) an output sampling and generates an uplink signal. The uplink signal is transmitted by using an antenna to the base station in the foregoing embodiment. In a downlink, the antenna receives a downlink signal transmitted by the base station in the foregoing embodiment. The receiver 1102 adjusts (for example, by means of filtering, amplification, down-conversion, and digitization) a signal received from the antenna and provides an input sampling. In the modem processor 1105, an encoder 1106 receives service data and a signaling message to be sent in an uplink, and processes (for example, by means of formatting, coding, and interleaving) the service data and the signaling message. A modulator 1107 further processes (for example, by means of symbol mapping and modulation) the encoded service data and signaling message, and provides an output sampling. A demodulator 1109 processes (for example, by means of demodulation) the input sampling and provides symbol estimation. A decoder 1108 processes (for example, by means of de-interleaving and decoding) the symbol estimation and provides the decoded data and signaling message that are sent to the UE. The encoder 1106, the modulator 1107, the demodulator 1109, and the decoder 1108 may be implemented by using the integrated modem processor 1105. These units perform processing according to a radio access technology (such as an access technology of LTE or another evolved system) used by a radio access network.

(41) The method and the apparatus are based on a same inventive concept. Because a problem-solving principle of the apparatus is similar to that of the method, mutual reference may be made to implementations of the method and the apparatus, and repeated description is not provided.

(42) It should be noted that, module division in this embodiment of the present application is an example, is merely logical function division, and may be other division in actual implementation. In addition, function modules in embodiments of the present application may be integrated into one processing module, or each of the modules may exist alone physically, or two or more modules are integrated into one module. The integrated module may be implemented in a form of hardware, or may be implemented in a form of a software function module.

(43) When the integrated module is implemented in the form of a software function module and sold or used as an independent product, the integrated module may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of the present application essentially, or the part contributing to the conventional art, or all or a part of the technical solutions may be implemented in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) or a processor to perform all or a part of the steps of the methods described in the embodiments of the present application. The foregoing storage medium includes: any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc.

(44) A person skilled in the art should understand that the embodiments of the present application may be provided as a method, a system, or a computer program product. Therefore, the present application may use a form of hardware-only embodiments, software-only embodiments, or embodiments with a combination of software and hardware. Moreover, the present application may use a form of a computer program product that is implemented on one or more computer-usable storage media (including but not limited to a disk memory, a CD-ROM, an optical memory) that include computer-usable program code.

(45) The present application is described with reference to the flowcharts and/or block diagrams of the method, the device (system), and the computer program product according to the embodiments of the present application. It should be understood that computer program instructions may be used to implement each process and/or each block in the flowcharts and/or the block diagrams and a combination of a process and/or a block in the flowcharts and/or the block diagrams. These computer program instructions may be provided for a general-purpose computer, a dedicated computer, an embedded processor, or a processor of another programmable data processing device to generate a machine, so that the instructions executed by a computer or a processor of another programmable data processing device generate an apparatus for implementing a specific function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

(46) These computer program instructions may be stored in a computer readable memory that can instruct the computer or another programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory generate an artifact that includes an instruction apparatus. The instruction apparatus implements a specific function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

(47) These computer program instructions may be loaded onto a computer or another programmable data processing device, so that a series of operations and steps are performed on the computer or another programmable device, thereby generating computer-implemented processing. Therefore, the instructions executed on the computer or another programmable device provide steps for implementing a specific function in one or more processes in the flowcharts and/or in one or more blocks in the block diagrams.

(48) Although some embodiments of the present application have been described, a person skilled in the art can make changes and modifications to these embodiments once they learn the basic inventive concept. Therefore, the following claims are intended to be construed as to cover the embodiments and all changes and modifications falling within the scope of the present application.

(49) Obviously, a person skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. The present application is intended to cover these modifications and variations provided that they fall within the scope of protection defined by the following claims and their equivalent technologies.