Remote radio unit, combiner / splliter unit, communication apparatus and communication system

Abstract

The present application relates to the technical field of communications. Provided are a remote radio unit, a combiner / splitter unit, a communication apparatus and a communication system, which solve the problem in the prior art of the use of a legacy traditional indoor distribution system being limited. The remote radio unit comprises at least one frequency division duplex (FDD) receiving port, and at least one time division duplex (TDD) frequency shift port used for transmitting a radio frequency signal and a local oscillator signal, wherein a transmission frequency band corresponding to the FDD receiving port is different from a transmission frequency band corresponding to the TDD frequency shift port, and the transmission frequency band corresponding to the TDD frequency shift port is equal to the sum of the frequency band of the radio frequency signal transmitted by the TDD frequency shift port and the frequency band of the local oscillator signal transmitted thereby.

Description

A radio remote unit, a combining and splitting unit, a communication device and a communication system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on November 15, 2023, with application number 202311526992.7 and application name “A radio frequency remote unit, combining and splitting unit, communication device and communication system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a radio remote unit, a combining and splitting unit, a communication device, and a communication system. Background Art

[0003] With the development of diversified 5G communication services, typical 5G communication services have placed higher demands on existing networks in terms of high speed, high flexibility, multiple connections, low latency, high reliability, and network openness. When users move from outdoor to indoor locations, the user terminal's network needs to switch from 5G to 4G, and network instability may occur during this handover.

[0004] Reusing the existing network system means that when building a new communication system, the infrastructure and equipment of the existing network are fully utilized for deployment. Reusing the existing network system can effectively utilize the existing infrastructure and equipment, reduce the demand for new infrastructure and equipment, and thus save costs. In the case of reusing the traditional indoor distributed system, the existing technology usually deploys the existing 4G long-term evolution (LTE) network and the 5G new radio (NR) network on a common cable. However, the frequency band range supported by the above-mentioned traditional indoor distributed system is limited, and it cannot support the channel transmission of 5G NR, thus limiting its use.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a radio frequency remote unit, a combining and splitting unit, a communication device and a communication system, which solve the problem of limited use of traditional indoor distributed systems in the prior art.

[0007] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0008] On the first aspect, a radio frequency remote unit is provided, which includes at least one frequency division duplex (FDD) receiving port, for example, which can be used to receive radio frequency signals in the frequency band of a 4G communication system; and at least one time division duplex (TDD) frequency shift port, which is used to transmit radio frequency signals and local oscillator signals; wherein the transmission frequency band corresponding to the FDD receiving port is different from the transmission frequency band corresponding to the TDD frequency shift port, and the transmission frequency band corresponding to the TDD frequency shift port is equal to the sum of the frequency band of the radio frequency signal transmitted by the TDD frequency shift port and the frequency band of the local oscillator signal, that is, the TDD frequency shift port can be used to receive or send signals in the above-mentioned transmission frequency band in a frequency shifting manner, and the frequency shifting can refer to shifting the signal of a higher transmission frequency band to the radio frequency signal and local oscillator signal of a lower frequency band, or shifting the radio frequency signal and local oscillator signal of a lower frequency band to the signal of a higher transmission frequency band, for example, for transmitting radio frequency signals in the frequency band of a 5G communication system in a frequency shifting manner.

[0009] In the above solution, the remote radio unit includes at least one FDD receive port and at least one TDD frequency-shift port. The at least one FDD receive port can be used to receive signals in the 4G communication system frequency band, and the at least one TDD frequency-shift port can be used to receive or transmit signals in the 5G communication system frequency band by frequency-shifting. In this way, the remote radio unit can simultaneously transmit signals in the transmission frequency bands corresponding to different communication systems. When used to reuse a traditional distributed indoor system, it is not affected by the frequency bands supported by the reused traditional distributed indoor system. This enables the evolution of high-bandwidth co-cable deployment of distributed indoor 4G LTE communication systems and 5G NR communication systems, meeting the needs of maximizing network traffic transmission.

[0010] In conjunction with the first aspect, in one possible implementation, the transmission frequency band corresponding to the at least one FDD receiving port is the frequency band of the 4G communication system, and the transmission frequency band corresponding to the at least one TDD frequency shift port is the frequency band of the 5G communication system. In the above possible implementation, the radio frequency remote unit can be used to simultaneously transmit signals of the transmission frequency bands corresponding to different communication systems, and when applied to a reused traditional indoor distributed system, it is not affected by the frequency band supported by the reused traditional indoor distributed system, thereby enabling the evolution of large-bandwidth co-cable deployment of the indoor distributed 4G LTE system and the 5G NR system, and meeting the needs of maximizing network traffic transmission.

[0011] In conjunction with the first aspect, the at least one FDD receive port includes a first FDD receive port, and the transmission frequency band corresponding to the first FDD receive port is a first frequency band. In the above possible implementation, the radio remote unit can receive radio frequency signals of the first frequency band corresponding to an FDD system (e.g., a 4G LTE communication system) through the first FDD receive port without receiving them through the radio frequency unit corresponding to the FDD system, thereby achieving separation of reception and transmission of the FDD system, thereby achieving lossless transmission of the FDD system.

[0012] In conjunction with the first aspect, in one possible implementation, the at least one FDD receiving port further includes a second FDD receiving port, the transmission frequency band corresponding to the second FDD receiving port is a second frequency band, and the first frequency band is different from the second frequency band. In the above possible implementation, the radio remote unit can receive radio frequency signals of the second frequency band corresponding to the FDD system (e.g., a 4G LTE communication system) through the second FDD receiving port without receiving them through the radio frequency unit corresponding to the FDD system, thereby achieving separation of reception and transmission of the FDD system, thereby achieving lossless transmission of the FDD system.

[0013] In combination with the first aspect, in one possible implementation, the at least one TDD frequency shift port includes a first TDD frequency shift port, and the transmission frequency band corresponding to the first TDD frequency shift port is a third frequency band. In the above possible implementation, the at least one TDD frequency shift port includes a first TDD frequency shift port, and the first TDD frequency shift port can be used to transmit a signal of the third frequency band of the TDD system (for example, a 5G NR system) in a frequency shift manner, so that the radio frequency remote unit can be used to transmit a signal corresponding to a communication system with a higher transmission frequency band, and when applied to a legacy distributed indoor system, it is not affected by the frequency band supported by the legacy distributed indoor system.

[0014] In combination with the first aspect, in a possible implementation, the at least one TDD frequency shift port further includes a second TDD frequency shift port, the transmission frequency band corresponding to the second TDD frequency shift port is a fourth frequency band, and the third frequency band is different from the fourth frequency band. In the above possible implementation, the at least one TDD frequency shift port further includes a second TDD frequency shift port, and the second TDD frequency shift port can be used to transmit the signal of the fourth frequency band of the TDD system (for example, the 5G NR system) in a frequency shift manner, so that the radio frequency remote unit can be used to transmit the signal corresponding to the communication system with a higher transmission frequency band, and when applied to the reuse of the traditional indoor distributed system, it is not affected by the frequency band supported by the reuse of the traditional indoor distributed system.

[0015] On the second aspect, a combining and splitting unit is provided, which includes at least one frequency division duplex (FDD) transmitting port, for example, which can be used to send radio frequency signals in the frequency band of a 4G communication system; the at least one frequency division duplex (FDD) receiving port, for example, which can be used to receive radio frequency signals in the frequency band of a 4G communication system; the at least one time division duplex (TDD) frequency shifting port, for transmitting radio frequency signals and local oscillator signals; wherein the transmission frequency band corresponding to the FDD transmitting port and the FDD receiving port is different from the transmission frequency band corresponding to the TDD frequency shifting port, and the transmission frequency band corresponding to the TDD frequency shifting port is equal to the sum of the frequency band of the radio frequency signal and the frequency band of the local oscillator signal transmitted by the TDD frequency shifting port, that is, the TDD frequency shifting port can be used to receive or send signals in the above-mentioned transmission frequency band in a frequency shifting manner, and the frequency shifting can refer to shifting the signal of a higher transmission frequency band to the radio frequency signal and local oscillator signal of a lower frequency band, or shifting the radio frequency signal and local oscillator signal of a lower frequency band to the signal of a higher transmission frequency band, for example, for transmitting radio frequency signals in the frequency band of a 5G communication system in a frequency shifting manner.

[0016] In the possible implementations described above, the at least one FDD transmit port and at least one FDD receive port included in the combiner / splitter unit can be used to transmit and receive signals in the 4G communication system frequency band, respectively, and at least one TDD frequency shift port can be used to receive or transmit signals in the 5G communication system frequency band by frequency shifting. In this way, the combiner / splitter unit can be used to simultaneously transmit signals in the transmission frequency bands corresponding to different communication systems, and when used to reuse a traditional distributed indoor system, it is not affected by the frequency bands supported by the reused traditional distributed indoor system. This enables the evolution of large-bandwidth co-cable deployment of the distributed indoor 4G LTE system and the 5G NR system, meeting the needs of maximizing network traffic transmission.

[0017] In combination with the second aspect, in one possible implementation, the at least one FDD transmitting port includes a first FDD transmitting port, and the transmission frequency band corresponding to the first FDD transmitting port is a first frequency band; the at least one FDD receiving port includes a first FDD receiving port, and the transmission frequency band corresponding to the first FDD receiving port is a second frequency band. In the above possible implementation, the combining and splitting unit can receive the radio frequency signal of the first frequency band corresponding to the FDD system (for example, the 4G LTE communication system) through the first FDD receiving port, and send the radio frequency signal of the second frequency band corresponding to the FDD system (for example, the 4G LTE communication system) through the first FDD receiving port, that is, the combining and splitting unit simultaneously receives and sends signals of different frequency bands corresponding to the FDD system, thereby realizing the separation of reception and transmission of the same frequency band of the FDD system, thereby realizing lossless transmission of the FDD system.

[0018] In combination with the second aspect, in a possible implementation, the at least one FDD transmitting port also includes a second FDD transmitting port, and the transmission frequency band corresponding to the second FDD transmitting port is the third frequency band; the at least one FDD receiving port also includes a second FDD receiving port, and the transmission frequency band corresponding to the second FDD receiving port is the fourth frequency band, and the third frequency band is different from the fourth frequency band. In the above possible implementation, the combining and splitting unit can receive the radio frequency signal of the second frequency band corresponding to the FDD system (for example, the 4G LTE communication system) through the second FDD receiving port, and send the radio frequency signal of the first frequency band corresponding to the FDD system (for example, the 4G LTE communication system) through the second FDD receiving port, that is, the combining and splitting unit simultaneously receives and sends signals of different frequency bands corresponding to the FDD system, thereby realizing the separation of reception and transmission of the same frequency band of the FDD system, thereby realizing lossless transmission of the FDD system.

[0019] In conjunction with the second aspect, in one possible implementation, the at least one TDD frequency shift port includes a first TDD frequency shift port, and the transmission frequency band corresponding to the first TDD frequency shift port is the fifth frequency band. In the above possible implementation, the at least one TDD frequency shift port includes a first TDD frequency shift port, and the first TDD frequency shift port can be used to transmit signals of the third frequency band of the TDD system (e.g., the 5G NR system) in a frequency shifted manner, so that the radio frequency remote unit can be used to transmit signals corresponding to a communication system with a higher transmission frequency band, and when applied to a legacy distributed indoor system, it is not affected by the frequency band supported by the legacy distributed indoor system.

[0020] In combination with the second aspect, in one possible implementation, the at least one TDD frequency shift port further includes a second TDD frequency shift port, the transmission frequency band corresponding to the second TDD frequency shift port is the sixth frequency band, and the fifth frequency band is different from the sixth frequency band. In the above possible implementation, the at least one TDD frequency shift port further includes a second TDD frequency shift port, and the second TDD frequency shift port can be used to transmit the signal of the fourth frequency band of the TDD system (for example, the 5G NR system) in a frequency shift manner, so that the radio frequency remote unit can be used to transmit the signal corresponding to the communication system with a higher transmission frequency band, and when applied to the reuse of the traditional indoor distributed system, it is not affected by the frequency band supported by the reuse of the traditional indoor distributed system.

[0021] According to a third aspect, a communication device is provided. The communication device includes a first remote radio frequency unit and a second remote radio frequency unit. The second remote radio frequency unit is the remote radio frequency unit provided by the first aspect or any possible implementation of the first aspect.

[0022] In combination with the third aspect, in a possible implementation, the communication device further includes the combining and splitting unit provided by the second aspect or any possible implementation of the second aspect.

[0023] In a fourth aspect, a communication system is provided, including a baseband unit, a first radio frequency remote unit, a second radio frequency remote unit, a combiner / splitter unit, a distributed antenna system and a mixing antenna, wherein the second radio frequency remote unit is the radio frequency remote unit provided by the above-mentioned first aspect or any possible implementation method of the first aspect, and the combiner / splitter unit is the combiner / splitter unit provided by the above-mentioned second aspect or any possible implementation method of the second aspect.

[0024] It can be understood that the beneficial effects that can be achieved by any of the communication devices and communication systems provided above can correspond to the beneficial effects of the radio frequency remote unit and the combining and splitting unit provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic structural diagram of a communication system;

[0026] FIG2 is a schematic diagram of the structure of a communication system provided in an embodiment of the present application;

[0027] FIG3 is a schematic diagram of the structure of another communication system provided in an embodiment of the present application;

[0028] FIG4 is a schematic structural diagram of another communication system provided in an embodiment of the present application;

[0029] FIG5 is a schematic diagram of the structure of another communication system provided in an embodiment of the present application;

[0030] FIG6 is a schematic structural diagram of another communication system provided in an embodiment of the present application;

[0031] FIG7 is a schematic diagram of the structure of another communication system provided in an embodiment of the present application;

[0032] FIG8 is a schematic structural diagram of another communication system provided in an embodiment of the present application;

[0033] FIG9 is a schematic diagram of the structure of another communication system provided in an embodiment of the present application;

[0034] FIG10 is a schematic structural diagram of another communication system provided in an embodiment of the present application;

[0035] FIG11 is a schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can represent: a, b, c, a and b, a and c, b and c, a, b and c; where a, b and c can be single or multiple.

[0037] The embodiments of this application use terms such as "first" and "second" to distinguish objects with similar names, functions, or effects. Those skilled in the art will understand that terms such as "first" and "second" do not limit the quantity or order of execution. The term "coupled" is used to indicate an electrical connection, including direct connection via wires or connectors or indirect connection via other devices. Therefore, "coupling" should be considered a broadly defined electronic communication connection.

[0038] It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0039] Before introducing the embodiments of the present application, the application scenarios involved in the present application are first introduced and explained.

[0040] With the development of diversified 5G communication services, typical 5G communication services have placed higher demands on existing networks in terms of high speed, high flexibility, multiple connections, low latency, high reliability, and network openness. When users move from outdoor to indoor locations, the user terminal's network needs to switch from 5G to 4G, and network instability may occur during this handover.

[0041] Reusing existing networks refers to deploying existing infrastructure and equipment when building new communications systems. This effectively utilizes existing infrastructure and equipment, reducing the need for new infrastructure and equipment and thus saving costs. Existing technologies utilize the existing 4G Long Term Evolution (LTE) network and the 5G New Radio (NR) network using the same cable, while reusing traditional indoor distributed systems.

[0042] In one implementation, the frequency division duplex (FDD) 4G LTE (1.8G / 2.1G band) module and the time division duplexing (TDD) 5G NR (3.5G band) module are combined through a point of interface (POI) and fed into a single-channel distributed antenna system (DAS). The DAS system transmits the signal to the indoor antenna, which then receives and transmits the signal, thereby realizing the co-cable deployment of FDD 4G LTE and TDD 5G NR, providing users with a stable network environment indoors.

[0043] For example, Figure 1 is a schematic diagram of the structure of a communication system. The communication system may include a room-based signal source, a multi-system access point (POI) combiner, a DAS system, and a room-based antenna. The room-based signal source may include a baseband unit (BBU), a 4G radio remote unit (RRU), and a 5G RRU. The first output end of the BBU is coupled to the input end of the 4G RRU, and the second output end of the BBU is coupled to the first input end of the 5G RRU. The transmission end of the 4G RRU is coupled to the first transmission end of the POI combiner, and the transmission end of the 5G RRU is coupled to the second transmission end of the POI combiner. The third transmission end of the POI combiner is coupled to the first transmission end of the DAS system, and the second transmission end of the DAS system is coupled to the transmission end of the room-based antenna. In Figure 1, the room-based antenna includes channel 1 and channel 2. Channel 1 is used to transmit 1.8G or 2.1G radio frequency signals RF1, and channel 2 is used to transmit 3.5G radio frequency signals RF2.

[0044] Among them, the 4G RRU can be used to receive and send radio frequency signals in the 1.8G frequency band or the 2.1G frequency band in the form of FDD, and the 5G RRU can be used to receive and send radio frequency signals in the 3.5G frequency band in the form of TDD.

[0045] Optionally, the DAS system may include a power splitter and at least one coupler, the first transmission end of the power splitter is coupled to the third transmission end of the POI combiner, the second transmission end of the power splitter is coupled to the input end of the coupler, the output end of the coupler is coupled to the transmission end of the indoor antenna, and the coupling end of the coupler can be coupled to the input end of another coupler.

[0046] Specifically, the BBU can output a first baseband signal and a second baseband signal through an optical fiber module, and input the first baseband signal and the second baseband signal into the 4G RRU and 5G RRU, respectively. The 4G RRU and 5G RRU can each output a radio frequency signal of a corresponding frequency band based on the baseband signals they receive. The POI combiner can combine the two radio frequency signals and transmit the combined radio frequency signal to the indoor antenna through the DAS system. The indoor antenna then sends the radio frequency signal.

[0047] In the above technical solution, the DAS system only supports transmission in the 700MHz-2.6GHz frequency band. The transmission frequency band of TDD 5G NR is 3.5G, which makes it difficult to meet the transmission needs of large broadband. In addition, the existing single-channel DAS system can only meet the single-stream transmission of TDD 5G NR network traffic, which cannot maximize the traffic and is difficult to meet the needs of 5G network high-traffic transmission indoors.

[0048] Based on this, the embodiments of the present application provide a communication system that can be used to fully utilize the DAS system to implement frequency band signal transmission of different communication systems. The technical solutions provided by the embodiments of the present application can be applied to various communication systems based on indoor distributed systems for signal transmission. For example, these different communication systems can include 2G, 3G, 4G, 5G, and any other communication systems that may appear in the future. The following describes the communication system provided by the present application.

[0049] Figure 2 is a schematic diagram of the structure of a communication system provided by an embodiment of the present application. The communication system may include a baseband unit, a first radio remote unit (RRU), a second RRU, a combiner / splitter unit, a distributed antenna system (DAS), and a frequency-mixing antenna. The baseband unit may be coupled to the first and second RRUs via optical fibers and optical modules. The first and second RRUs are further coupled to the combiner / splitter unit, which is coupled to the DAS system. The DAS system is further configured to couple to the frequency-mixing antenna.

[0050] The baseband unit may be used to send baseband signals to the first RRU and the second RRU, or receive baseband signals sent by the first RRU and the second RRU; the baseband unit may also process the baseband signals.

[0051] In one possible embodiment, the first RRU includes at least one FDD transceiver port. Optionally, the at least one FDD transceiver port can function as at least one FDD transmit port, i.e., the first RRU can be used to transmit radio frequency signals corresponding to the FDD system. For example, the first RRU supports the transmission of 1T1R 4G LTE services and can specifically be used only to implement the transmission of 4G LTE downlink services. Optionally, the at least one FDD transceiver port can also function as at least one FDD transmit port, i.e., the first RRU includes at least one FDD transmit port.

[0052] The at least one FDD transceiver port includes one or more FDD transceiver ports. For example, the at least one FDD transceiver port includes a first FDD transceiver port, or includes a first FDD transceiver port and a second FDD transceiver port. The transmission frequency bands corresponding to the first FDD transceiver port and the second FDD transceiver port may be the same or different. In one example, the transmission frequency bands corresponding to the first FDD transceiver port and the second FDD transceiver port are different, the transmission frequency band corresponding to the first FDD transceiver port is a first frequency band, the transmission frequency band corresponding to the second FDD transceiver port is a second frequency band, and the first frequency band and the second frequency band are different.

[0053] Optionally, the first RRU may be an RRU corresponding to an FDD system (or called an FDD RRU). For example, the first RRU may be an RRU corresponding to a 4G FDD LTE system. The transmission frequency band corresponding to the first RRU may be a transmission frequency band corresponding to the 4G FDD LTE system, and the transmission frequency band may be 1.8G or 2.1G.

[0054] Furthermore, as shown in Figure 3, the first RRU may also include one or more of a digital processing unit, a power supply and clock circuit, a radio frequency transceiver link, a power amplifier, a control circuit, a receiving amplifier, and a filter. The digital processing unit may be responsible for processing baseband signals; the power supply and clock circuit may be responsible for providing power and synchronization signals to the first RRU; the radio frequency transceiver link may be responsible for data transmission; the power amplifier may be responsible for enhancing the strength of the transmitted signal; the control circuit may be responsible for controlling the operation of the first RRU; the receiving amplifier may be responsible for amplifying the received radio frequency signal; and the filter may be responsible for eliminating unwanted signal components. Figure 3 illustrates this by taking the example of a first RRU including two FDD transmit ports.

[0055] In one possible embodiment, the second RRU includes at least one FDD receive port and at least one TDD frequency shift port. That is, the second RRU can be used to receive RF signals corresponding to the FDD system, and to receive or transmit RF signals corresponding to the TDD system. For example, the second RRU supports the transmission of nTnR TDD 5G NR services and xR FDD LTE uplink services, where n and x are integers greater than or equal to 1.

[0056] The at least one FDD receiving port may include one or more FDD receiving ports, for example, the at least one FDD receiving port includes a first FDD receiving port, or includes a first FDD receiving port and a second FDD receiving port. The transmission frequency bands corresponding to the first FDD receiving port and the second FDD receiving port may be the same or different. In one example, the transmission frequency bands corresponding to the first FDD receiving port and the second FDD receiving port are different, the transmission frequency band corresponding to the first FDD receiving port is a first frequency band, the transmission frequency band corresponding to the second FDD receiving port is a second frequency band, and the first frequency band is different from the second frequency band. Optionally, the at least one FDD receiving port may be a receiving port corresponding to an FDD system, for example, a receiving port corresponding to a 4G FDD LTE system, for receiving radio frequency signals with a transmission frequency band of 1.8G or 2.1G.

[0057] In addition, the at least one TDD frequency shift port can be used to transmit radio frequency signals and local oscillator signals. The at least one TDD frequency shift port may include one or more TDD frequency shift ports. For example, the at least one TDD frequency shift port includes a first TDD frequency shift port, or includes a first TDD frequency shift port and a second TDD frequency shift port. The transmission frequency bands corresponding to the first TDD frequency shift port and the second TDD frequency shift port may be the same or different. In one example, the transmission frequency bands corresponding to the first TDD frequency shift port and the second TDD frequency shift port are different, the transmission frequency band corresponding to the first TDD frequency shift port is the third frequency band, and the transmission frequency band corresponding to the second TDD frequency shift port is the fourth frequency band, and the third frequency band is different from the fourth frequency band.

[0058] The above-mentioned TDD frequency shift port can be used to transmit signals in a frequency shifting manner. The frequency shifting may refer to shifting the signal of a higher transmission frequency band to a radio frequency signal and a local oscillator signal of a lower frequency band, or shifting the radio frequency signal and the local oscillator signal of a lower frequency band to a signal of a higher transmission frequency band, for example, for transmitting the radio frequency signal of the frequency band of the 5G communication system in a frequency shifting manner.

[0059] Optionally, the second RRU may be an RRU corresponding to a TDD system (or referred to as a frequency-shift RRU). For example, the second RRU may be an RRU corresponding to a 5G TDD NR system, and the transmission frequency band corresponding to the second RRU may be a transmission frequency band corresponding to a 5G TDD NR system. In the second RRU, the transmission frequency band corresponding to the FDD receiving port is different from the transmission frequency band corresponding to the TDD frequency-shift port, and the transmission frequency band corresponding to the TDD frequency-shift port is equal to the sum of the frequency band of the radio frequency signal transmitted by the TDD frequency-shift port and the frequency band of the local oscillator signal. Exemplarily, the transmission frequency band corresponding to the TDD frequency-shift port may be a 3.5G radio frequency signal, wherein the at least one TDD frequency-shift port may specifically use a frequency-shift band below 2.6G (a non-standard 3GPP frequency band).

[0060] Optionally, the first and second RRUs can be co-located with the BBU to enable the transmission and reception of multi-band, multi-standard base station communication RF signals. Furthermore, the second RRU can be in the form of an nTmR port (T stands for transmit, R stands for receive), for example, to support nTnR TDD 5G NR services and xR FDD LTE uplink services, where n, m, and x can be greater than or equal to 1.

[0061] Furthermore, as shown in Figure 3, the second RRU may also include one or more of a digital processing unit, a power supply and clock circuit, a local oscillator transmission link, a frequency-converting RF transceiver link, a power amplifier, a control circuit, a receiving amplifier, and a filter. The digital processing unit may be used to process baseband signals; the power supply and clock circuit may be used to provide power and synchronization to the second RRU; the local oscillator transmission link may be used to emit a frequency-stable local oscillator signal; the frequency-converting RF transceiver link may be used to up-convert baseband signals and local oscillator signals into RF signals, or down-convert RF signals into baseband signals and local oscillator signals; the power amplifier may be used to enhance the strength of the transmitted signal; the control circuit may be used to control the operation of the second RRU; the receiving amplifier may be used to amplify the received RF signal; and the filter may be used to eliminate unwanted signal components. Figure 3 illustrates an example of a second RRU including two FDD receiving ports and two TDD frequency-shifting ports. The communication system shown in Figure 3 may also be referred to as a schematic diagram of a 2T2R 4G LTE + 2T2R 5G NR co-cable transmission network.

[0062] In a possible embodiment, the combining and splitting unit includes at least one FDD transmitting port and at least one FDD receiving port (i.e., the FDD transmitting and receiving ports are set separately), and at least one TDD frequency shift port. Among them, the at least one FDD transmitting port can be used to be connected to the at least one FDD transmitting and receiving port of the first RRU in a one-to-one correspondence. The at least one FDD receiving port can be used to be connected to the at least one FDD receiving port of the second RRU in a one-to-one correspondence. The at least one TDD frequency shift port can be used to be connected to the at least one TDD frequency shift port of the second RRU in a one-to-one correspondence. The combining and splitting unit can be used to combine the signals sent by the first RRU and the second RRU into one signal and then transmit it through the DAS system and the antenna, and can also be used to split the signals transmitted by the antenna and the DAS system into two corresponding signals and transmit them to the first RRU and the second RRU. Figure 3 is used as an example to illustrate that the combining and splitting unit includes two FDD transmitting ports, two FDD receiving ports and two TDD frequency shift ports.

[0063] In a possible embodiment, the DAS system may include a power splitter and at least one coupler, the first transmission end of the power splitter is coupled to the third transmission end of the combiner / splitter unit, the second transmission end of the power splitter is coupled to the input end of the coupler, the output end of the coupler is coupled to the transmission end of the indoor antenna, and the coupling end of the coupler can be coupled to the input end of another coupler.

[0064] In one possible embodiment, the hybrid antenna may include an FDD antenna and a TDD antenna, and the TDD antenna may include a multiple-input multiple-output MIMO antenna. The FDD antenna may be used to receive and transmit FDD-related signals, and the TDD antenna may be used to receive or transmit TDD-related signals.

[0065] Taking the example of a first RRU including two FDD transceiver ports and a second RRU including two FDD receive ports and two TDD frequency shift ports, the specific structures of the first RRU, the second RRU and the combining / splitting unit in the communication system are illustrated in FIG4 .

[0066] In Figure 4, the first RRU includes a first FDD transceiver port (denoted as FDD TRX port 1) and a second FDD transceiver port (denoted as FDD TRX port 2), and the corresponding supported frequency bands are RF1 / RF3 and RF2 / RF4. The second RRU includes a first FDD receive port (denoted as FDD RX port 1) and a second FDD receive port (denoted as FDD RX port 2), as well as a first TDD frequency shift port (denoted as TDD frequency shift port 1) and a second TDD frequency shift port (denoted as TDD frequency shift port 2), and the corresponding supported frequency bands are RF3, RF4, RF5+LO1, and RF6+LO2. The combiner / splitter unit includes a first FDD transmit port (denoted as FDD TX port 1), a second FDD transmit port (denoted as FDD TX port 2), a first FDD receive port (denoted as FDD RX port 1), a second FDD receive port (denoted as FDD RX port 2), and a first TDD frequency shift port (denoted as TDD frequency shift port 1) and a second TDD frequency shift port (denoted as TDD frequency shift port 2). The corresponding supported frequency bands are RF1, RF2, RF3, RF4, RF5+LO1, and RF6+LO2, respectively. RF1, RF2, RF3, RF4, RF5, RF6, LO1, and LO2 represent different frequency bands or signals of different frequency bands.

[0067] In one example, when the first RRU is an RRU of a 4G LTE system (for example, supporting frequency bands including 1.8 GHz and 2.1 GHz) and the second RRU is an RRU of a 5G NR system (for example, supporting frequency bands including 3.5 GHz), the frequency band ranges of RF1 and FR3 can be two different frequency bands corresponding to 1.8 GHz, the frequency band ranges of RF2 and RF4 can be two different frequency bands corresponding to 2.1 GHz, and RF5+LO1=RF6+LO2, and the corresponding frequency band range can be the frequency band corresponding to 3.5 GHz. RF5 and RF6 can be different, and LO1 and LO2 can also be different.

[0068] In Figure 4, the connection between the FDD TRX port 1 of the first RRU and the FDD TX port 1 of the combiner / splitter unit is represented as ①, and the connection between the FDD TRX port 2 and the FDD TX port 2 of the combiner / splitter unit is represented as ②; the connection between the FDD RX port 1 of the second RRU and the FDD RX port 1 of the combiner / splitter unit is represented as ③, and the connection between the FDD RX port 2 and the FDD RX port 2 of the combiner / splitter unit is represented as ④, the connection between the TDD frequency shift port 1 and the TDD frequency shift port 1 of the combiner / splitter unit is represented as ⑤, and the connection between the TDD frequency shift port 2 and the TDD frequency shift port 2 of the combiner / splitter unit is represented as ⑥.

[0069] It can be understood that the above Figure 4 uses the example of the first RRU, the second RRU and the combining and splitting unit including ports of different frequency bands. In actual applications, the first RRU, the second RRU and any one of the combining and splitting units may also include multiple ports corresponding to the same frequency band. For example, the first RRU may include two ports corresponding to RF1 / RF3, or include two ports corresponding to RF2 / RF4, etc. The embodiment of the present application does not impose specific restrictions on this.

[0070] Based on this, the first RRU, the second RRU and the combining and splitting unit in the communication system can be used to transmit the signals of the 1.8G frequency band, the 2.1G frequency band of the 4G LTE system and the 3.5G frequency band of the two-way 5G NR system, thereby enabling the DAS system to realize the dual-stream co-cable deployment of the 4G LTE system and the 5G NR system, and greatly improve the downlink traffic. In addition, when the second RRU is the RRU corresponding to the 5G NR system, the frequency band below 2.6G (non-standard 3GPP frequency band) is used to achieve 5G NR coverage while maximizing the use of the existing DAS system (without the need for new stations). The second RRU also has a multi-band and multi-standard passive intermodulation (PIM) interference cancellation function, which can automatically complete the interference cancellation compensation caused by the poor PIM indicators of the DAS system, and realize 4G LTE lossless uplink service transmission. Among them, when the PIM correction capability of the second RRU is high, lossless co-cable deployment of indoor single-frequency 4GLTE single-stream and 5G NR dual-stream can be achieved.

[0071] For ease of understanding, the structure of the communication device is illustrated below by taking the first RRU as an RRU of a 4G LTE system and the second RRU as an RRU of a 5G NR system as an example.

[0072] In one example, as shown in Figure 5, the first RRU includes FDD TRX port 1 and FDD TRX port 2 supporting frequency bands RF1 / RF3; the second RRU includes FDD RX port 1 supporting frequency band RF3, TDD frequency shift port 1 supporting frequency bands RF5+LO1, and TDD frequency shift port 2 supporting frequency bands RF6+LO2; the combiner / splitter unit includes FDD TX port 1 supporting frequency band RF1, FDD TX port 2 supporting frequency band RF2, FDD RX port 1 supporting frequency band RF3, FDD RX port 2 supporting frequency band RF4, TDD frequency shift port 1 supporting frequency bands RF5+LO1, and TDD frequency shift port 2 supporting frequency bands RF6+LO2. The communication system shown in Figure 5 can also be referred to as a communication system for 1T1R LTE + 2T2R NR co-cable transmission networking.

[0073] Specifically, the FDD TRX port 1 of the first RRU can be connected to the FDD TX port 1 of the combiner / splitter unit to realize the transmission of FDD LTE signals, and the corresponding frequency band can be RF1; the FDD RX port 1 of the second RRU can be connected to the FDD RX port 1 of the combiner / splitter unit to realize the reception of FDD LTE signals, and the corresponding frequency band can be RF2, that is, the first RRU and the second RRU jointly complete the reception and transmission of FDD LTE signals. In addition, the TDD frequency shift port 1 of the second RRU can be connected to the TDD frequency shift port 1 of the combiner / splitter unit, and the TDD frequency shift port 2 of the second RRU can be connected to the TDD frequency shift port 2 of the combiner / splitter unit to realize the reception or transmission of two TDD NR signals, and the corresponding frequency bands are RF5+LO1 and RF6+LO, and RF5+LO1=RF6+LO2. During the transmission of the above signals, the mixing antenna in the communication system can be used to restore the two frequency-shifted signals (i.e., RF5+LO1=RF6+LO2) to signals in the 3GPP frequency band (e.g., 3.5HGz), thereby realizing dual-stream transmission of TDD NR and single-stream transmission of FDD LTE.

[0074] Optionally, the second RRU can simultaneously obtain information on the five downlink frequency bands RF1, RF5, RF6, LO1, and LO2 through the CPRI interface. Through the internal algorithm solution unit, the intermodulation cancellation value is automatically compensated to the uplink service of RF3 within the second RRU, thereby realizing lossless transmission of 4G LTE services.

[0075] In another example, as shown in Figure 6, the first RRU includes FDD TRX port 1 and FDD TRX port 2 supporting frequency bands RF2 / RF4; the second RRU includes FDD RX port 2 supporting frequency band RF4, TDD frequency shift port 1 supporting frequency bands RF5+LO1, and TDD frequency shift port 2 supporting frequency bands RF6+LO2; the combiner / splitter unit includes FDD TX port 1 supporting frequency band RF1, FDD TX port 2 supporting frequency band RF2, FDD RX port 1 supporting frequency band RF3, FDD RX port 2 supporting frequency band RF4, TDD frequency shift port 1 supporting frequency bands RF5+LO1, and TDD frequency shift port 2 supporting frequency bands RF6+LO2. The communication system shown in Figure 6 can also be referred to as a communication system for 1T1R LTE + 2T2R NR co-cable transmission networking.

[0076] Specifically, the FDD TRX port 2 of the first RRU can be connected to the FDD TX port 2 of the combiner / splitter unit to realize the transmission of FDD LTE signals, and the corresponding frequency band can be RF2; the FDD RX port 2 of the second RRU can be connected to the FDD RX port 2 of the combiner / splitter unit to realize the reception of FDD LTE signals, and the corresponding frequency band can be RF4, that is, the first RRU and the second RRU jointly complete the transmission and reception of FDD LTE signals. In addition, the TDD frequency shift port 1 of the second RRU can be connected to the TDD frequency shift port 1 of the combiner / splitter unit, and the TDD frequency shift port 2 of the second RRU can be connected to the TDD frequency shift port 2 of the combiner / splitter unit to realize the transmission or reception of TDD NR signals, and the corresponding frequency bands are RF5+LO1 and RF6+LO2, and RF5+LO1=RF6+LO2. During the transmission of the above signals, the mixing antenna in the communication system can be used to restore the two frequency-shifted signals (i.e., RF5+LO1=RF6+LO2) to signals in the 3GPP frequency band (e.g., 3.5HGz), thereby realizing dual-stream transmission of TDD NR and single-stream transmission of FDD LTE.

[0077] In another example, as shown in Figure 7, the first RRU includes FDD TRX port 1 and FDD TRX port 2 supporting frequency bands RF1 / RF3; the second RRU includes FDD RX port 1 supporting frequency band RF3 and TDD frequency shift port 1 supporting frequency band RF5+LO1; the combiner / splitter unit includes FDD TX port 1 supporting frequency band RF1, FDD TX port 2 supporting frequency band RF2, FDD RX port 1 supporting frequency band RF3, FDD RX port 2 supporting frequency band RF4, TDD frequency shift port 1 supporting frequency band RF5+LO1, and TDD frequency shift port 2 supporting frequency band RF6+LO2. The communication system shown in Figure 7 can also be referred to as a communication system for 1T1RLTE+1T1R NR co-cable transmission networking.

[0078] Specifically, the FDD TRX port 1 of the first RRU can be connected to the FDD TX port 1 of the combiner / splitter unit to transmit FDD LTE signals, and the corresponding frequency band is RF1; the FDD RX port 1 of the second RRU can be connected to the FDD RX port 1 of the combiner / splitter unit to receive FDD LTE signals, and the corresponding frequency band is RF3, that is, the first RRU and the second RRU jointly complete the transmission and reception of FDD LTE signals. In addition, the TDD frequency shift port 1 of the second RRU can be connected to the TDD frequency shift port 1 of the combiner / splitter unit to receive and transmit TDD NR signals, and the corresponding frequency band is RF5+LO1.

[0079] Alternatively, in conjunction with Figure 7, as shown in Figure 8, the second RRU includes an FDD RX port 1 supporting frequency band RF3 and a TDD frequency shift port 2 supporting frequency band RF6+LO2. The TDD frequency shift port 2 of the second RRU can be used to connect to the TDD frequency shift port 2 of the combiner / splitter unit to transmit or receive TDD NR signals, corresponding to the frequency band RF6+LO2. The communication system shown in Figure 8 can also be referred to as a communication system for 1T1R LTE + 1T1R NR co-cable transmission networking.

[0080] In another example, as shown in Figure 9, the first RRU includes FDD TRX port 1 and FDD TRX port 2 supporting frequency bands RF2 / RF4; the second RRU includes FDD RX port 2 supporting frequency band RF4 and TDD frequency shift port 1 supporting frequency band RF5+LO1; the combiner / splitter unit includes FDD TX port 1 supporting frequency band RF1, FDD TX port 2 supporting frequency band RF2, FDD RX port 1 supporting frequency band RF3, FDD RX port 2 supporting frequency band RF4, TDD frequency shift port 1 supporting frequency band RF5+LO1, and TDD frequency shift port 2 supporting frequency band RF6+LO2. The communication system shown in Figure 9 can also be referred to as a communication system for 1T1RLTE+1T1RNR co-cable transmission networking.

[0081] Specifically, the FDD TRX port 2 of the first RRU can be connected to the FDD TX port 2 of the combiner / splitter unit to transmit FDD LTE signals, and the corresponding frequency band is RF2; the FDD RX port 2 of the second RRU can be connected to the FDD RX port 2 of the combiner / splitter unit to receive FDD LTE signals, and the corresponding frequency band is RF4, that is, the first RRU and the second RRU jointly complete the transmission and reception of FDD LTE signals. In addition, the TDD frequency shift port 1 of the second RRU can be connected to the TDD frequency shift port 1 of the combiner / splitter unit to transmit or receive TDD NR signals, and the corresponding frequency band is RF5+LO1.

[0082] Alternatively, in conjunction with Figure 9, as shown in Figure 10, the second RRU includes an FDD RX port 2 supporting frequency band RF4 and a TDD frequency shift port 2 supporting frequency band RF6+LO2. The TDD frequency shift port 2 of the second RRU can be used to connect to the TDD frequency shift port 2 of the combiner / splitter unit to implement reception or transmission of TDD NR signals, corresponding to the frequency band RF6+LO2. The communication system shown in Figure 10 can also be referred to as a communication system for 1T1R LTE + 1T1R NR co-cable transmission networking.

[0083] In an embodiment of the present application, the first RRU includes at least one FDD transceiver port, the second RRU includes at least one FDD receive port and at least one TDD frequency shift port, and the combining and splitting unit includes at least one FDD transmit port and at least one FDD receive port, so that the communication system can be used to simultaneously transmit signals of transmission frequency bands corresponding to different communication systems, and when applied to reusing traditional indoor distributed systems, it is not affected by the frequency bands supported by the reusing traditional indoor distributed systems, thereby enabling the large-bandwidth co-cable deployment evolution of indoor distributed 4G communication systems and 5G NR communication systems, and meeting the needs of maximizing network traffic transmission.

[0084] In another embodiment of the present application, an RRU is further provided. The RRU may be the second RRU provided above.

[0085] In another embodiment of the present application, a combining and splitting unit is further provided, which may be the combining and splitting unit provided above.

[0086] In yet another embodiment of the present application, a communication device is provided, as shown in Figure 11 , which includes the first RRU and the second RRU provided above. Furthermore, the communication device may also include the combiner / splitter unit provided above.

[0087] It can be understood that all relevant contents of the communication system provided in Figures 2 to 10 above can be referred to the description of the corresponding embodiments of the above-mentioned RRU, combining and splitting unit and communication device, and the embodiments of the present application will not be repeated here.

[0088] Finally, it should be noted that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A radio remote unit, characterized in that: include: At least one frequency division duplex (FDD) receiving port; At least one time division duplex (TDD) frequency shift port for transmitting a radio frequency signal and a local oscillator signal; Among them, the transmission frequency band corresponding to the FDD receiving port is different from the transmission frequency band corresponding to the TDD frequency shift port, and the transmission frequency band corresponding to the TDD frequency shift port is equal to the sum of the frequency band of the RF signal transmitted by the TDD frequency shift port and the frequency band of the local oscillator signal.

2. The radio remote unit according to claim 1, characterized in that: The transmission frequency band corresponding to the at least one frequency division duplex FDD receiving port is the frequency band of the 4G communication system, and the transmission frequency band corresponding to the at least one time division duplex TDD frequency shifting port is the frequency band of the 5G communication system.

3. The radio remote unit according to claim 1 or 2, characterized in that: The at least one FDD receiving port includes a first FDD receiving port, and a transmission frequency band corresponding to the first FDD receiving port is a first frequency band.

4. The radio remote unit according to claim 3, characterized in that: The at least one FDD receiving port further includes a second FDD receiving port, the transmission frequency band corresponding to the second FDD receiving port is a second frequency band, and the first frequency band is different from the second frequency band.

5. The radio remote unit according to any one of claims 1 to 4, characterized in that: The at least one TDD frequency shift port includes a first TDD frequency shift port, and a transmission frequency band corresponding to the first TDD frequency shift port is a third frequency band.

6. The radio remote unit according to claim 5, characterized in that: The at least one TDD frequency shift port further includes a second TDD frequency shift port, the transmission frequency band corresponding to the second TDD frequency shift port is a fourth frequency band, and the third frequency band is different from the fourth frequency band.

7. A combining and splitting unit, characterized in that: include: At least one frequency division duplex (FDD) transmission port; At least one frequency division duplex (FDD) receiving port; At least one time division duplex (TDD) frequency shift port for transmitting a radio frequency signal and a local oscillator signal; Among them, the transmission frequency bands corresponding to the FDD transmitting port and the FDD receiving port are different from the transmission frequency band corresponding to the TDD frequency shift port, and the transmission frequency band corresponding to the TDD frequency shift port is equal to the sum of the frequency band of the RF signal transmitted by the TDD frequency shift port and the frequency band of the local oscillator signal.

8. The combining and splitting unit according to claim 7, characterized in that: The at least one FDD transmitting port includes a first FDD transmitting port, and the transmission frequency band corresponding to the first FDD transmitting port is a first frequency band; the at least one FDD receiving port includes a first FDD receiving port, and the transmission frequency band corresponding to the first FDD receiving port is a second frequency band.

9. The combining and splitting unit according to claim 7 or 8, characterized in that: The at least one FDD transmitting port also includes a second FDD transmitting port, and the transmission frequency band corresponding to the second FDD transmitting port is a third frequency band; the at least one FDD receiving port also includes a second FDD receiving port, and the transmission frequency band corresponding to the second FDD receiving port is a fourth frequency band, and the third frequency band is different from the fourth frequency band.

10. The combining and splitting unit according to any one of claims 7 to 9, characterized in that: The at least one TDD frequency shift port includes a first TDD frequency shift port, and a transmission frequency band corresponding to the first TDD frequency shift port is a fifth frequency band.

11. The combining and splitting unit according to claim 10, characterized in that: The at least one TDD frequency shift port further includes a second TDD frequency shift port, the transmission frequency band corresponding to the second TDD frequency shift port is a sixth frequency band, and the fifth frequency band is different from the sixth frequency band.

12. A communication device, characterized in that: The method comprises a first remote radio frequency unit and a second remote radio frequency unit, wherein the second remote radio frequency unit is the remote radio frequency unit according to any one of claims 1 to 6.

13. The communication device according to claim 12, characterized in that: The communication device also includes: a combining and splitting unit as described in any one of claims 7-11.

14. A communication system, characterized in that: It includes a baseband unit, a first radio frequency remote unit, a second radio frequency remote unit, a combining and splitting unit, a distributed antenna system and a mixing antenna, the second radio frequency remote unit is the radio frequency remote unit as described in any one of claims 1-6, and the combining and splitting unit is the combining and splitting unit as described in any one of claims 7-11.

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