WO2021133243A1 - Apparatuses, system and methods for mimo transmission in a wireless communication system - Google Patents

Apparatuses, system and methods for mimo transmission in a wireless communication system Download PDF

Info

Publication number
WO2021133243A1
WO2021133243A1 PCT/SG2019/050631 SG2019050631W WO2021133243A1 WO 2021133243 A1 WO2021133243 A1 WO 2021133243A1 SG 2019050631 W SG2019050631 W SG 2019050631W WO 2021133243 A1 WO2021133243 A1 WO 2021133243A1
Authority
WO
WIPO (PCT)
Prior art keywords
downlink signal
head
signal
far
unit
Prior art date
Application number
PCT/SG2019/050631
Other languages
French (fr)
Inventor
Wee Loon ANG
Original Assignee
Aoao Global Pte Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aoao Global Pte Ltd filed Critical Aoao Global Pte Ltd
Priority to PCT/SG2019/050631 priority Critical patent/WO2021133243A1/en
Publication of WO2021133243A1 publication Critical patent/WO2021133243A1/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices
    • H04W88/085—Access point devices with remote components

Definitions

  • the invention relates to MIMO transmission in a wireless communication system, more particularly, apparatuses, system and methods for MIMO transmission in a wireless communication system via a single cable, e.g. a coaxial cable.
  • CDMA Code Division Multiple Access
  • FDMA Frequency Division Multiple Access
  • TDMA Time Division Multiple Access
  • LTE 3GPP Long Term Evolution
  • OFDMA Orthogonal Data Access
  • multiple wireless communication systems can support communications with a plurality of user equipment (”UE”) simultaneously.
  • Each UE communicates with one or more base stations through uplink and downlink transmission.
  • the uplink refers to communication link from UE to the base station(s) whereas downlink refers to communication link from the base station(s) to UE.
  • These communication links may be configured using a single input single output (“SISO”) method, a multiple input single output (“MISO”) method, or a multiple input multiple output (“MIMO”) method.
  • SISO single input single output
  • MISO multiple input single output
  • MIMO multiple input multiple output
  • Wireless communication systems with MIMO method to perform data transmission use multiple transmission antennas and multiple receiving antennas.
  • MIMO channels formed by multiple transmission antennas and multiple receiving antennas may be divided into independent channels which are called spatial channels to support improved performance, for example, higher throughput and/or higher reliability of MIMO systems.
  • multiple pairs of transmission cables corresponding to the number of MIMO antennas are required to transmit MIMO signals from a base station to UE’s antennas. This may result in various issues in implementation of MIMO transmission in a wireless communication system, e.g. high cost and space for cabling installation, especially in a specific building or space, and long turn-around time for implementation.
  • Embodiments of the invention provide a cost effective, space-saving and more efficient solution for implementing MIMO transmission in a wireless communication system.
  • a first apparatus for MIMO transmission in a wireless communication system comprises: a first head- end input/output terminal configured to receive a first high frequency (HF) downlink signal; a second head-end input/output terminal configured to receive a second HF downlink signal which have the same physical cell identification (PCI) as the first HF downlink signal; a head-end downlink signal amplification unit configured to convert the second HF downlink signal into an intermediate frequency (IF) downlink signal; a head-end signal processing unit configured to combine the first HF downlink signal and the IF downlink signal; and a head-end cable terminal configured to transmit the combined signals from the head-end signal processing unit to a far-end unit via a single cable.
  • HF high frequency
  • PCI physical cell identification
  • a second apparatus for MIMO transmission in a wireless communication system comprises: a far-end cable terminal configured to receive downlink signals from a head-end unit through a single cable; a far-end signal processing unit configured to separate the downlink signals received from the far-end cable terminal into a first HF downlink signal and an IF downlink signal; a far-end downlink signal amplification unit configured to convert the IF downlink signal from the far-end signal processing unit into a second HF downlink signal; a first far-end unit input/output terminal configured to transmit the first HF downlink signal from the far-end signal processing unit to one or more service antennas or any telecom system; and a second far-end input/output terminal configured to transmit the second HF downlink signal to one or more service antennas or any telecom system.
  • a system for MIMO transmission in a wireless communication system comprises: a first apparatus and at least one second apparatus according to embodiments of the invention, wherein the communication between the first apparatus and the at least one second apparatus is conducted through a single cable, e.g. a coaxial cable.
  • a method for MIMO transmission at the first apparatus in a wireless communication system is provided.
  • the method comprises: receiving a first high frequency (HF) downlink signal through a first head-end input/output terminal; receiving a second HF downlink signal through a second head-end input/output terminal; converting the second HF downlink signal into an intermediate frequency (IF) downlink signal; combining the first HF downlink signal and the IF downlink signal; and transmitting the combined signals to a far-end unit through a head-end unit cable terminal via a single cable.
  • HF high frequency
  • IF intermediate frequency
  • a method for MIMO transmission at the second apparatus in a wireless communication system comprises: receiving downlink signals from a head-end unit through a far-end cable terminal via a single cable; separating the received downlink signals into a first HF downlink signal and an IF downlink signal; converting the IF downlink signal into a second HF downlink signal; transmitting the first HF downlink signal to one or more than one service antennas or any telecom system through a first far-end unit input/output terminal; and transmitting the second HF downlink signal to one or more than one service antennas or any telecom system through a second far-end input/output terminal .
  • a single cable is required for communication of MIMO signals from a base station to UE’s antennas in a wireless communication system, e.g. a 5G communication system.
  • MIMO transmission can be implemented more easily and efficiently, and the cost and space required for cabling installation can be reduced significantly.
  • Figure 1 is a schematic diagram illustrating a system for MIMO transmission in a wireless communication system according to a first embodiment of the invention
  • Figure 2 is a schematic diagram illustrating a head-end downlink signal amplification unit according to one embodiment of the invention
  • Figure 3 is a schematic diagram illustrating a far-end downlink signal amplification unit according to one embodiment of the invention
  • Figure 4(a) is a flowchart illustrating a method for MIMO downlink transmission at the head-end unit according to the first embodiment of the invention
  • Figure 4(b) is a flowchart illustrating a method for uplink transmission at the head- end unit according to the first embodiment of the invention
  • Figure 5(a) is a flowchart illustrating a method for MIMO downlink transmission at the tar-end unit according to the first embodiment of the invention
  • Figure 5(b) is a flowchart illustrating a method for uplink transmission at the tar-end unit according to the first embodiment of the invention
  • Figure 6 is a schematic diagram showing a system for MIMO transmission in a wireless communication system according to a second embodiment of the invention.
  • Embodiments described in the context of one of the methods or systems are analogously valid for the other methods or systems. Similarly, embodiments described in the context of a method are analogously valid for a system, and vice versa.
  • the articles “a”, “an” and “the” as used with regard to a feature or element include a reference to one or more of the features or elements.
  • the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.
  • Some embodiments of the invention provide a first apparatus for MIMO transmission in a wireless communication system.
  • the first apparatus may be installed at the base station side in the wireless communication system.
  • the first apparatus is configured to conduct downlink transmission and at least includes: a first head-end input/output terminal configured to receive a first high frequency (HF) downlink signal; a second head-end input/output terminal configured to receive second HF downlink signal which has the same physical cell identification (PCI) as the first HF downlink signal; a head-end downlink signal amplification unit configured to convert the second HF downlink signal into an intermediate frequency (IF) downlink signal; a head-end signal processing unit configured to combine the first HF downlink signal and the IF downlink signal; and a head-end cable terminal configured to transmit the combined signals from the head-end signal processing unit to a far-end unit via a single cable.
  • HF high frequency
  • PCI physical cell identification
  • the first apparatus may be further configured to conduct uplink transmission.
  • the head-end cable terminal may be further configured to receive a HF uplink signal from a far-end unit through the single cable and transmit the received HF uplink signal to the head-end signal processing unit, wherein the head-end signal processing unit may be further configured to transmit the received HF uplink signal to a base station or a repeater through the first and/or the second head-end input/output terminal.
  • the first apparatus may further include an uplink signal division unit which is configured to divide the HF uplink signal from the head-end signal processing unit into a first frequency part and a second frequency part; wherein the first frequency part is transmitted to the base station or the repeater through the first head-end input/output terminal, and the second frequency part is transmitted to the base station or the repeater through the second head-end input/output terminal.
  • an uplink signal division unit which is configured to divide the HF uplink signal from the head-end signal processing unit into a first frequency part and a second frequency part; wherein the first frequency part is transmitted to the base station or the repeater through the first head-end input/output terminal, and the second frequency part is transmitted to the base station or the repeater through the second head-end input/output terminal.
  • the first apparatus may further include a head-end signal separation unit which is configured to transmit an downlink signal from the second head-end input/output terminal to the head-end downlink signal amplification unit, and transmit an uplink signal received from the head-end signal processing unit or the uplink signal division unit to the second head-end input/output terminal.
  • a head-end signal separation unit which is configured to transmit an downlink signal from the second head-end input/output terminal to the head-end downlink signal amplification unit, and transmit an uplink signal received from the head-end signal processing unit or the uplink signal division unit to the second head-end input/output terminal.
  • the head-end downlink signal amplification unit may include a heterodyne amplifier.
  • the heterodyne amplifier includes a first amplifier, a forward down converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, which are sequentially connected in series.
  • Some embodiments of the invention provide a second apparatus for MIMO transmission in a wireless communication system.
  • the second apparatus may be installed at the user terminal side in the wireless communication system.
  • the second apparatus is configured to conduct downlink transmission and at least includes: a tar-end cable terminal configured to receive a downlink signal from a head-end unit through a single cable; a tar-end signal processing unit configured to separate the downlink signal received from the tar-end cable terminal into a first HF downlink signal and an IF downlink signal; a tar-end downlink signal amplification unit configured to convert the IF downlink signal from the tar-end signal processing unit into a second HF downlink signal; a first tar-end unit input/output terminal configured to transmit the first HF downlink signal from the tar-end signal processing unit to one or more service antennas or any telecom system; and a second tar-end input/output terminal configured to transmit the second HF downlink signal to one or more service antennas or any telecom system.
  • the second apparatus may further include an output adjustment unit which is configured to detect a first power level of the first HF downlink signal transmitted to the first tar-end unit input/output terminal via a bypass line, detect a second power level of the second HF downlink signal from the tar-end signal amplification unit and adjust the second power level based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
  • an output adjustment unit which is configured to detect a first power level of the first HF downlink signal transmitted to the first tar-end unit input/output terminal via a bypass line, detect a second power level of the second HF downlink signal from the tar-end signal amplification unit and adjust the second power level based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
  • the output adjustment unit may include a first detection unit configured to detect the first power level of the first HF downlink signal; a second detection unit configured to detect the second power level of the second HF downlink signal; and a controller configured to adjust the second power level based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
  • the far-end downlink signal amplification unit may include a heterodyne amplifier.
  • the heterodyne amplifier includes a first amplifier, a forward up converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, a variable attenuator M and a power amplifier, which are sequentially connected in series.
  • the second apparatus may be further configured to conduct uplink transmission.
  • the first and/or the second far-end input/output terminal may be further configured to receive uplink signals and transmit the received uplink signals to the far-end signal processing unit; wherein the far-end signal processing unit is further configured to transmit the uplink signals to the far-end cable terminal; and the far-end cable terminal is further configured to transmit the uplink signals to the head-end unit via the single cable.
  • the first and/or the second far-end input/output terminal may be further configured to receive uplink signals and transmit the received uplink signals to the far-end signal processing unit; wherein the far-end signal processing unit is further configured to transmit the uplink signals to the far-end cable terminal; and the far-end cable terminal is further configured to transmit the uplink signals to the head-end unit via the single cable.
  • Some embodiments of the invention provide a system for MIMO transmission in a wireless communication system.
  • the system may include a first apparatus and at least one second apparatus wherein the communication between the first apparatus and the at least one second apparatus is conducted through a single cable, e.g. a coaxial cable.
  • a single cable e.g. a coaxial cable.
  • the wireless communication system mentioned in the embodiments of the invention may include a 2G, 3G, 3.5G, 4G, 4.5G, 5G communication system or any communication system that supports usage of coaxial cable infrastructure.
  • Some embodiments of the invention provide a base station side method for MIMO transmission at the head-end unit in a wireless communication system.
  • This method at least includes: receiving a first high frequency (HF) downlink signal through a first head-end input/output terminal; receiving a second HF downlink signal through a second head-end input/output terminal; converting the second HF downlink signal into an intermediate frequency (IF) downlink signal; combining the first HF downlink signal and the IF downlink signal; and transmitting the combined signals to a far-end unit through a head-end unit cable terminal via a single cable.
  • HF high frequency
  • IF intermediate frequency
  • this method also includes uplink transmission.
  • the method may further include: receiving a HF uplink signal from the far-end unit through the head-end cable terminal via the single cable; and transmitting the received HF uplink signal to a base station or a repeater through the first and/or the second head- end input/output terminal.
  • the method may further include: before transmitting the received HF uplink signal to the base station or the repeater, dividing the received HF uplink signal into a first frequency part and a second frequency part; transmitting the first frequency part to the base station or the repeater through the first head-end input/output terminal, and transmitting the second frequency part to the base station or the repeater through the second head-end input/output terminal.
  • the step of converting the second HF downlink signal into an IF downlink signal may include: using a heterodyne amplifier to convert the second HF downlink signal into the IF downlink signal wherein the heterodyne amplifier includes a first amplifier, a forward down converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, which are sequentially connected in series.
  • the heterodyne amplifier includes a first amplifier, a forward down converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, which are sequentially connected in series.
  • the method at least includes: receiving a signal from a head-end unit through a far-end cable terminal via a single cable; separating the received signal into a first HF downlink signal and an IF downlink signal; converting the IF downlink signal into a second HF downlink signal; transmitting the first HF downlink signal to one or more than one service antennas or any telecom system through a first far-end unit input/output terminal; and transmitting the second HF downlink signal to one or more than one service antennas or any telecom system through a second far-end input/output terminal.
  • the method may further include: detecting a first power level of the first HF downlink signal transmitted to the first far-end unit input/output terminal via a bypass line, detecting a second power level of the second HF downlink signal, and adjusting the second power level of the second HF downlink signal based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
  • the step of converting the IF downlink signal into a second HF downlink signal may include: using a heterodyne amplifier to convert the IF downlink signal into second HF downlink signal wherein the heterodyne amplifier includes a first amplifier, a forward up converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, a variable attenuator and a power amplifier, which are sequentially connected in series.
  • the method may further include a process of uplink transmission.
  • the method may further include: receiving an uplink signal through the first or the second tar-end input/output terminal; and transmitting the received uplink signal to the head-end unit via the single cable.
  • FIG. 1 is a schematic diagram illustrating a system 10 for MIMO transmission in a wireless communication system according to a first embodiment of the invention.
  • the system 10 includes a head-end unit 100 and a tar-end unit 300.
  • the communication between the head-end unit 100 and the tar-end unit 300 is conducted via a single cable 200.
  • the single cable 200 may be a coaxial cable.
  • the head-end unit 100 and the tar-end unit 300 are used for both downlink and uplink transmission.
  • the head-end unit 100 includes a first head-end input/output terminal 110, a second head-end input/output terminal 111 , a head-end cable terminal 112, a head-end signal separation unit 130, a head-end signal processing unit 140, a head-end downlink signal amplification unit 170, and an uplink signal division unit 180.
  • the first head-end input/output terminal 110 is configured to receive a first high frequency (HF) downlink signal from a base station or a repeater and transmit the first HF downlink signal to the signal processing unit 140 through a bypass line 160; and transmit a first frequency uplink signal received from the uplink signal division unit 180 to a base station or a repeater.
  • HF high frequency
  • the second head-end input/output terminal 111 is configured to receive a second HF downlink signal which has the same physical cell identification (PCI) as the first HF downlink signal and transmit the second HF downlink signal to the head-end signal separation unit 130; and transmit a second frequency uplink signal from the head-end signal separation unit 130 to a base station or a repeater.
  • PCI physical cell identification
  • the head-end signal separation unit 130 is used to separate received downlink and uplink signals. Specifically, the head-end signal separation unit 130 is configured to transmit the second HF downlink signal from the second head-end input/output terminal 111 to the head-end downlink signal amplification unit 170, and transmit the second frequency uplink signal from the uplink signal division unit 180 to the second head-end input/output terminal 111.
  • the head-end downlink signal amplification unit 170 which is connected between the head-end signal separation unit 130 and the signal processing unit 140 is used to form a forward amplification path.
  • the head-end downlink signal amplification unit 170 is configured to convert the second HF downlink signal into an intermediate frequency (IF) downlink signal and transmit the IF downlink signal to the head-end signal processing unit 140.
  • IF intermediate frequency
  • FIG. 2 is a schematic diagram illustrating a head-end downlink signal amplification unit 170 according to one embodiment of the invention.
  • the downlink signal amplification unit 170 may be a heterodyne amplifier.
  • the heterodyne amplifier includes an amplifier A, a forward down converter including a local oscillator B and a mixer C, an amplifier D, a filter E and an amplifier F, which are sequentially connected in series.
  • the head-end signal processing unit 140 is configured to combine the first HF downlink signal from the first head-end input/output terminal 110 and the IF downlink signal from the head-end downlink signal amplification unit 170, transmit the combined signals to the head-end cable terminal 112; receive an uplink signal from the head-end cable terminal 112 and transmit the received uplink signal to the uplink signal division unit 180.
  • the uplink signal division unit 180 is configured to divide the HF uplink signal from the head-end signal processing unit 140 into a first frequency uplink signal and a second frequency uplink signal; wherein the first frequency uplink signal is transmitted to the first head-end input/output terminal 110, and the second frequency uplink signal is transmitted to the head-end signal separation unit 130.
  • the head-end cable terminal 112 is installed at one side of the head-end unit 100 for connection to the single cable 200.
  • the head-end cable terminal 112 is configured to transmit the combined signals from the head-end signal processing unit 140 to the far-end unit 300 via the single cable 200 and transmit an uplink signal from the far-end unit 300 to the head-end signal processing unit 140.
  • the head-end unit 100 may be optional in other embodiments of the invention.
  • the head-end unit may not include the head-end signal separation unit 130 and the uplink signal division unit 180 if the head- end unit is only used for downlink transmission.
  • the head-end unit may not include the uplink signal division unit 180, accordingly, the head-end signal separation unit 130 may be configured as an uplink band filter to transmit an uplink signal from the head-end signal processing unit 140 to the second head-end input/output terminal 111.
  • Far-End Unit 300 (The second apparatus)
  • the far-end unit 300 includes a first far-end input/output terminal 310, a second far-end input-output terminal 311 , a far-end cable terminal 312, a far-end signal processing unit 340, a far-end downlink signal amplification unit 370 and an output adjustment unit 390.
  • the far-end cable terminal 312 is installed at one side of the far-end unit 300 for the connection to the single cable 200 to link up with the head-end cable terminal 112.
  • the far- end cable terminal 312 is configured to receive a downlink signal from the head-end unit 100 through the single cable 200, and transmit an uplink signal from the far-end signal processing unit 340 to the head-end cable terminal 112 through the single cable 200.
  • the far-end signal processing unit 340 is connected to the far-end cable terminal 312 and configured to separate the downlink signal received from the far-end cable terminal 112 of the head-end unit 100 into a first HF downlink signal and an IF downlink signal; transmit the first HF downlink signal to the first far-end input/output terminal 310 through a bypass line 360, and transmit the IF downlink signal to the far-end downlink signal amplification unit 370.
  • the far-end downlink signal amplification unit 370 is connected between the far-end signal processing unit 340 and the second far-end input-output terminal 311 to form a forward amplification path.
  • the far-end downlink signal amplification unit 370 is configured to convert the IF downlink signal from the far-end signal processing unit 340 into a second HF downlink signal, and transmit the second HF downlink signal to the second far-end input-output terminal 311 .
  • FIG 3 is a schematic diagram showing the far-end downlink signal amplification unit 370 according to one embodiment of the invention.
  • the far-end downlink signal amplification unit 370 may be a heterodyne amplifier.
  • the heterodyne amplifier includes an amplifier G, a forward up converter including a local oscillator H and a mixer I, an amplifier J, a filter K and an amplifier L, a variable attenuator M and a power amplifier N, which are sequentially connected in series.
  • the output adjustment unit 390 is used to adjust an output power level of the second HF downlink signal from the far-end downlink signal amplification unit 370.
  • the output adjustment unit 390 may include a first detection unit 391 configured to detect a first power level of the first HF downlink signal; a second detection unit 392 configured to detect a second power level of the second HF downlink signal; and a controller 393 configured to adjust the second power level, i.e. the output power level of the second HF downlink signal, based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
  • the controller 393 may be configured to adjust the second power level of the second HF downlink signal by controlling the variable attenuator M of the far-end downlink signal amplification unit 370 based on the detected first power level.
  • the first far-end unit input/output terminal 310 and the second far-end input/output terminal 311 are a pair of terminals installed at one side of the far-end unit 300 to connect to any MIMO capable antennas 400 and telecom systems.
  • the first far-end unit input/output terminal 310 is configured to transmit the first HF downlink signal from the far-end signal processing unit 340 to one or more service antennas or any telecom system; and receive uplink signals from one or more service antennas or any telecom system and transmit the received uplink signals to the far-end signal processing unit 340 through the bypass line 360.
  • the second far-end input/output terminal 311 is configured to transmit the second
  • the far-end unit 300 may not be used for uplink transmission, or maybe only one of the two terminals is used for uplink transmission, e.g. the first far-end input/output terminal 310.
  • the far-end unit 300 may not include the output adjustment unit 390.
  • Figure 4(a) is a flowchart illustrating a method 400a for MIMO downlink transmission at the head-end unit 100 according to the first embodiment of the invention.
  • the head-end unit 100 receives a first HF downlink signal through the first head-end input/output terminal 110; and receives a second HF downlink signal through the second head-end input/output terminal 111.
  • the head-end downlink signal application unit 170 in the head-end unit 100 converts the second HF downlink signal into an IF downlink signal.
  • the heterodyne amplifier as shown in Figure 2 may be used to convert the second HF downlink signal into the IF downlink signal.
  • the head-end signal processing unit 140 combines the first HF downlink signal and the IF downlink signal.
  • the combined signals are transmitted to the far-end unit 300 through the head-end cable terminal 112 via the single cable 200.
  • Figure 4(b) is a flowchart illustrating a method 400b for uplink transmission at the head-end unit 100 according to the first embodiment of the invention.
  • the head-end signal processing unit 140 receives a HF uplink signal from the far-end unit 300 through the head-end cable terminal 112 via the single cable 200.
  • the uplink signal division unit 180 divides the HF uplink signal from the head-end signal processing unit 140 via a bypass line 160 into a first frequency uplink signal/part and a second frequency uplink signal/part.
  • the first frequency uplink signal is transmitted to a base station or a repeater through the first head-end input/output terminal 110; and the second frequency uplink signal is transmitted to a base station or a repeater through the second head-end input/output terminal 111.
  • the head-end unit 100 may not include the uplink signal division unit 180. Accordingly, the received uplink signal may be transmitted to a base station or a repeater only through the first head-end input/output terminal 110.
  • the head-end signal separation unit 130 may be configured as an uplink band filter to transmit a received uplink signal from the head-end signal processing unit 140 to a base station and a repeater through the second head-end input/output terminal 111.
  • Figure 5(a) is a flowchart illustrating a method 500a for MIMO downlink transmission at the far-end unit 300 according to the first embodiment of the invention.
  • the far-end unit 300 receives downlink signals from the head-end unit 100 through the far-end cable terminal 312 via the single cable 200.
  • the far-end signal processing unit 340 separates the received downlink signals into a first HF downlink signal and an IF downlink signal.
  • the first HF downlink signal is transmitted to one or more than one service antennas or any telecom system through the first far-end unit input/output terminal 310.
  • the far-end downlink signal amplification unit 370 converts the IF downlink signal into a second HF downlink signal.
  • the heterodyne amplifier as shown in Figure 3 may be used to convert the IF downlink signal into the second HF downlink signal.
  • the output adjustment unit 390 detects a first power level of the first HF downlink signal transmitted to the first far-end unit input/output terminal 310 via the bypass line 360, detects a second power level of the second HF downlink signal, and adjusts the second power level of the second HF downlink signal based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
  • the second HF downlink signal is transmitted to one or more than one service antennas or any telecom system through the second far-end input/output terminal 311.
  • Figure 5(b) is a flowchart illustrating a method 500b for uplink transmission at the far- end unit 100 according to the first embodiment of the invention.
  • the far-end unit 300 receives an uplink signal through the first far-end input/output terminal 310 or the second far-end input/output terminal 311 .
  • the received uplink signal is transmitted to the far-end signal processing unit 340 via the bypass line 360.
  • the far-end signal processing unit 340 transmits the received uplink signal to the head-end unit 100 via the single cable 200. It should be noted that in some embodiments of the invention, the uplink signal may be only received through one of the first far-end input/output terminal 310 and the second far-end input/output terminal 311 .
  • FIG 6 is a schematic diagram showing a system 20 for MIMO transmission in a wireless communication system according to a second embodiment of the invention.
  • the system 20 includes a head-end unit 100 installed at the base station side and a plurality of far-end units 300 which are installed in the UEs side respectively.
  • the head-end unit 100 is connected to the plurality of far-end units 300 via a single cable 200 and the communication between the base station and the UEs’ antennas is performed via the single cable 200.
  • the wireless communication system in embodiments of the invention may be 2G, 3G, 3.5G, 4G, 4.5G, 5G communication system or any communication system that supports usage of coaxial cable infrastructure.
  • embodiments of the invention provide a head- end unit, a far-end unit, a system and methods for implementation of MIMO transmission in a wireless communication system.
  • embodiments of the invention provide a simple system for MIMO transmission since only one cable is required for the communication between a base station and the UEs’ antennas.
  • the cost and required space for cabling installation, as well as the turn- around time for implementation of MIMO transmission are reduced significantly.
  • the solution provided by embodiments of the invention may be used to cost effectively and efficiently implement or upgrade a 5G indoor coverage using the existing coaxial cable and/or common infrastructure. It is to be understood that the embodiments and features described above should be considered exemplary and not restrictive.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Embodiments of the invention provide apparatuses, system and methods for MIMO transmission in a wireless communication system. One apparatus comprises: a first head-end input/output terminal configured to receive a first high frequency (HF) downlink signal; a second head-end input/output terminal configured to receive a second HF downlink signal which have the same physical cell identification (PCI) as the first HF downlink signal; a head-end downlink signal amplification unit configured to convert the second HF downlink signal into an intermediate frequency (IF) downlink signal; a head-end signal processing unit configured to combine the first HF downlink signal and the IF downlink signal; and a head-end cable terminal configured to transmit the combined signals from the head-end signal processing unit to a far-end unit via a single cable.

Description

APPARATUSES, SYSTEM AND METHODS FOR MIMO TRANSMISSION
IN A WIRELESS COMMUNICATION SYSTEM
Field of Invention
The invention relates to MIMO transmission in a wireless communication system, more particularly, apparatuses, system and methods for MIMO transmission in a wireless communication system via a single cable, e.g. a coaxial cable.
Background
Multiple wireless communication systems such as Code Division Multiple Access (“CDMA”), Frequency Division Multiple Access (”FDMA”), Time Division Multiple Access (“TDMA”), 3GPP Long Term Evolution (“LTE”) and Orthogonal Frequency Division Multiple
Access (“OFDMA”) are widely implemented to provide various types of communication contents to all users by sharing available system resources, for example, bandwidths and transmission power.
In general, multiple wireless communication systems can support communications with a plurality of user equipment (”UE”) simultaneously. Each UE communicates with one or more base stations through uplink and downlink transmission. The uplink refers to communication link from UE to the base station(s) whereas downlink refers to communication link from the base station(s) to UE. These communication links may be configured using a single input single output (“SISO”) method, a multiple input single output (“MISO”) method, or a multiple input multiple output (“MIMO”) method.
Wireless communication systems with MIMO method to perform data transmission use multiple transmission antennas and multiple receiving antennas. MIMO channels formed by multiple transmission antennas and multiple receiving antennas may be divided into independent channels which are called spatial channels to support improved performance, for example, higher throughput and/or higher reliability of MIMO systems.
In an existing solution for achieving MIMO transmission in a wireless communication system, multiple pairs of transmission cables corresponding to the number of MIMO antennas are required to transmit MIMO signals from a base station to UE’s antennas. This may result in various issues in implementation of MIMO transmission in a wireless communication system, e.g. high cost and space for cabling installation, especially in a specific building or space, and long turn-around time for implementation.
Summary of Invention Embodiments of the invention provide a cost effective, space-saving and more efficient solution for implementing MIMO transmission in a wireless communication system.
According to one aspect of the invention, a first apparatus for MIMO transmission in a wireless communication system is provided. The first apparatus comprises: a first head- end input/output terminal configured to receive a first high frequency (HF) downlink signal; a second head-end input/output terminal configured to receive a second HF downlink signal which have the same physical cell identification (PCI) as the first HF downlink signal; a head-end downlink signal amplification unit configured to convert the second HF downlink signal into an intermediate frequency (IF) downlink signal; a head-end signal processing unit configured to combine the first HF downlink signal and the IF downlink signal; and a head-end cable terminal configured to transmit the combined signals from the head-end signal processing unit to a far-end unit via a single cable.
According to a second aspect of the invention, a second apparatus for MIMO transmission in a wireless communication system is provided, the second apparatus comprises: a far-end cable terminal configured to receive downlink signals from a head-end unit through a single cable; a far-end signal processing unit configured to separate the downlink signals received from the far-end cable terminal into a first HF downlink signal and an IF downlink signal; a far-end downlink signal amplification unit configured to convert the IF downlink signal from the far-end signal processing unit into a second HF downlink signal; a first far-end unit input/output terminal configured to transmit the first HF downlink signal from the far-end signal processing unit to one or more service antennas or any telecom system; and a second far-end input/output terminal configured to transmit the second HF downlink signal to one or more service antennas or any telecom system. According to a third aspect of the invention, a system for MIMO transmission in a wireless communication system is provided. The system comprises: a first apparatus and at least one second apparatus according to embodiments of the invention, wherein the communication between the first apparatus and the at least one second apparatus is conducted through a single cable, e.g. a coaxial cable. According to a fourth aspect of the invention, a method for MIMO transmission at the first apparatus in a wireless communication system is provided. The method comprises: receiving a first high frequency (HF) downlink signal through a first head-end input/output terminal; receiving a second HF downlink signal through a second head-end input/output terminal; converting the second HF downlink signal into an intermediate frequency (IF) downlink signal; combining the first HF downlink signal and the IF downlink signal; and transmitting the combined signals to a far-end unit through a head-end unit cable terminal via a single cable.
According to a fifth aspect of the invention, a method for MIMO transmission at the second apparatus in a wireless communication system is provided. The method comprises: receiving downlink signals from a head-end unit through a far-end cable terminal via a single cable; separating the received downlink signals into a first HF downlink signal and an IF downlink signal; converting the IF downlink signal into a second HF downlink signal; transmitting the first HF downlink signal to one or more than one service antennas or any telecom system through a first far-end unit input/output terminal; and transmitting the second HF downlink signal to one or more than one service antennas or any telecom system through a second far-end input/output terminal .
With the apparatuses, system and methods provided in embodiments of the invention, only a single cable is required for communication of MIMO signals from a base station to UE’s antennas in a wireless communication system, e.g. a 5G communication system. As such, MIMO transmission can be implemented more easily and efficiently, and the cost and space required for cabling installation can be reduced significantly.
Brief Description of the Drawings
The invention will be described in detail with reference to the accompanying drawings, in which:
Figure 1 is a schematic diagram illustrating a system for MIMO transmission in a wireless communication system according to a first embodiment of the invention;
Figure 2 is a schematic diagram illustrating a head-end downlink signal amplification unit according to one embodiment of the invention; Figure 3 is a schematic diagram illustrating a far-end downlink signal amplification unit according to one embodiment of the invention;
Figure 4(a) is a flowchart illustrating a method for MIMO downlink transmission at the head-end unit according to the first embodiment of the invention; Figure 4(b) is a flowchart illustrating a method for uplink transmission at the head- end unit according to the first embodiment of the invention;
Figure 5(a) is a flowchart illustrating a method for MIMO downlink transmission at the tar-end unit according to the first embodiment of the invention; Figure 5(b) is a flowchart illustrating a method for uplink transmission at the tar-end unit according to the first embodiment of the invention;
Figure 6 is a schematic diagram showing a system for MIMO transmission in a wireless communication system according to a second embodiment of the invention.
Detailed Description of Embodiments of the Invention In the following description, numerous specific details are set forth in order to provide a thorough understanding of various illustrative embodiments of the invention. It will be understood, however, to one skilled in the art, that embodiments of the invention may be practiced without some or all of these specific details. It is understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the invention.
Embodiments described in the context of one of the methods or systems are analogously valid for the other methods or systems. Similarly, embodiments described in the context of a method are analogously valid for a system, and vice versa.
Features that are described in the context of an embodiment may correspondingly be applicable to the same or similar features in the other embodiments. Features that are described in the context of an embodiment may correspondingly be applicable to the other embodiments, even if not explicitly described in these other embodiments. Furthermore, additions and/or combinations and/or alternatives as described for a feature in the context of an embodiment may correspondingly be applicable to the same or similar feature in the other embodiments.
As used herein, the articles “a”, “an” and “the” as used with regard to a feature or element include a reference to one or more of the features or elements. As used herein, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.
As used herein, the term “configured to” is interchangeable with “operative” or “adapted to”.
Some embodiments of the invention provide a first apparatus for MIMO transmission in a wireless communication system. The first apparatus may be installed at the base station side in the wireless communication system. The first apparatus is configured to conduct downlink transmission and at least includes: a first head-end input/output terminal configured to receive a first high frequency (HF) downlink signal; a second head-end input/output terminal configured to receive second HF downlink signal which has the same physical cell identification (PCI) as the first HF downlink signal; a head-end downlink signal amplification unit configured to convert the second HF downlink signal into an intermediate frequency (IF) downlink signal; a head-end signal processing unit configured to combine the first HF downlink signal and the IF downlink signal; and a head-end cable terminal configured to transmit the combined signals from the head-end signal processing unit to a far-end unit via a single cable.
In some embodiments of the invention, the first apparatus may be further configured to conduct uplink transmission. Accordingly, the head-end cable terminal may be further configured to receive a HF uplink signal from a far-end unit through the single cable and transmit the received HF uplink signal to the head-end signal processing unit, wherein the head-end signal processing unit may be further configured to transmit the received HF uplink signal to a base station or a repeater through the first and/or the second head-end input/output terminal.
In some embodiments of the invention, to further improve the speed of uplink transmission, the first apparatus may further include an uplink signal division unit which is configured to divide the HF uplink signal from the head-end signal processing unit into a first frequency part and a second frequency part; wherein the first frequency part is transmitted to the base station or the repeater through the first head-end input/output terminal, and the second frequency part is transmitted to the base station or the repeater through the second head-end input/output terminal.
In some embodiments of the invention, when the second head-end unit input/output terminal is used for both downlink and uplink transmission, the first apparatus may further include a head-end signal separation unit which is configured to transmit an downlink signal from the second head-end input/output terminal to the head-end downlink signal amplification unit, and transmit an uplink signal received from the head-end signal processing unit or the uplink signal division unit to the second head-end input/output terminal.
In some embodiments, the head-end downlink signal amplification unit may include a heterodyne amplifier. The heterodyne amplifier includes a first amplifier, a forward down converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, which are sequentially connected in series.
Some embodiments of the invention provide a second apparatus for MIMO transmission in a wireless communication system. The second apparatus may be installed at the user terminal side in the wireless communication system. The second apparatus is configured to conduct downlink transmission and at least includes: a tar-end cable terminal configured to receive a downlink signal from a head-end unit through a single cable; a tar-end signal processing unit configured to separate the downlink signal received from the tar-end cable terminal into a first HF downlink signal and an IF downlink signal; a tar-end downlink signal amplification unit configured to convert the IF downlink signal from the tar-end signal processing unit into a second HF downlink signal; a first tar-end unit input/output terminal configured to transmit the first HF downlink signal from the tar-end signal processing unit to one or more service antennas or any telecom system; and a second tar-end input/output terminal configured to transmit the second HF downlink signal to one or more service antennas or any telecom system.
In some embodiments of the invention, to synchronize the first and the second HF downlink signal, the second apparatus may further include an output adjustment unit which is configured to detect a first power level of the first HF downlink signal transmitted to the first tar-end unit input/output terminal via a bypass line, detect a second power level of the second HF downlink signal from the tar-end signal amplification unit and adjust the second power level based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
In one example, the output adjustment unit may include a first detection unit configured to detect the first power level of the first HF downlink signal; a second detection unit configured to detect the second power level of the second HF downlink signal; and a controller configured to adjust the second power level based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal. In some embodiments of the invention, the far-end downlink signal amplification unit may include a heterodyne amplifier. The heterodyne amplifier includes a first amplifier, a forward up converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, a variable attenuator M and a power amplifier, which are sequentially connected in series.
In some embodiments of the invention, the second apparatus may be further configured to conduct uplink transmission. Accordingly, the first and/or the second far-end input/output terminal may be further configured to receive uplink signals and transmit the received uplink signals to the far-end signal processing unit; wherein the far-end signal processing unit is further configured to transmit the uplink signals to the far-end cable terminal; and the far-end cable terminal is further configured to transmit the uplink signals to the head-end unit via the single cable. It should be noted that in some embodiments, maybe only one of the first and second far-end input/output terminals is configured to conduct uplink transmission, while in other embodiments, both of the first and second far-end input/output terminals may be configured to conduct uplink transmission.
Some embodiments of the invention provide a system for MIMO transmission in a wireless communication system. The system may include a first apparatus and at least one second apparatus wherein the communication between the first apparatus and the at least one second apparatus is conducted through a single cable, e.g. a coaxial cable. It should be noted that the wireless communication system mentioned in the embodiments of the invention may include a 2G, 3G, 3.5G, 4G, 4.5G, 5G communication system or any communication system that supports usage of coaxial cable infrastructure.
Some embodiments of the invention provide a base station side method for MIMO transmission at the head-end unit in a wireless communication system. This method at least includes: receiving a first high frequency (HF) downlink signal through a first head-end input/output terminal; receiving a second HF downlink signal through a second head-end input/output terminal; converting the second HF downlink signal into an intermediate frequency (IF) downlink signal; combining the first HF downlink signal and the IF downlink signal; and transmitting the combined signals to a far-end unit through a head-end unit cable terminal via a single cable.
In some embodiments of the invention, this method also includes uplink transmission. The method may further include: receiving a HF uplink signal from the far-end unit through the head-end cable terminal via the single cable; and transmitting the received HF uplink signal to a base station or a repeater through the first and/or the second head- end input/output terminal.
To further improve the speed of uplink transmission, the method may further include: before transmitting the received HF uplink signal to the base station or the repeater, dividing the received HF uplink signal into a first frequency part and a second frequency part; transmitting the first frequency part to the base station or the repeater through the first head-end input/output terminal, and transmitting the second frequency part to the base station or the repeater through the second head-end input/output terminal.
In some embodiments of the invention, the step of converting the second HF downlink signal into an IF downlink signal may include: using a heterodyne amplifier to convert the second HF downlink signal into the IF downlink signal wherein the heterodyne amplifier includes a first amplifier, a forward down converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, which are sequentially connected in series. Some embodiments of the invention also provide a user terminal side method for
MIMO transmission at the far-end unit in a wireless communication system. The method at least includes: receiving a signal from a head-end unit through a far-end cable terminal via a single cable; separating the received signal into a first HF downlink signal and an IF downlink signal; converting the IF downlink signal into a second HF downlink signal; transmitting the first HF downlink signal to one or more than one service antennas or any telecom system through a first far-end unit input/output terminal; and transmitting the second HF downlink signal to one or more than one service antennas or any telecom system through a second far-end input/output terminal.
In some embodiments of the invention, to synchronize the first and the second HF downlink signals, the method may further include: detecting a first power level of the first HF downlink signal transmitted to the first far-end unit input/output terminal via a bypass line, detecting a second power level of the second HF downlink signal, and adjusting the second power level of the second HF downlink signal based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal. In some embodiments of the invention, the step of converting the IF downlink signal into a second HF downlink signal may include: using a heterodyne amplifier to convert the IF downlink signal into second HF downlink signal wherein the heterodyne amplifier includes a first amplifier, a forward up converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, a variable attenuator and a power amplifier, which are sequentially connected in series.
In some embodiments of the invention, the method may further include a process of uplink transmission. The method may further include: receiving an uplink signal through the first or the second tar-end input/output terminal; and transmitting the received uplink signal to the head-end unit via the single cable.
Figure 1 is a schematic diagram illustrating a system 10 for MIMO transmission in a wireless communication system according to a first embodiment of the invention. As shown in Figure 1 , the system 10 includes a head-end unit 100 and a tar-end unit 300. The communication between the head-end unit 100 and the tar-end unit 300 is conducted via a single cable 200. The single cable 200 may be a coaxial cable. In this embodiment, the head-end unit 100 and the tar-end unit 300 are used for both downlink and uplink transmission.
Head-End Unit 100 (the first apparatus) In the this embodiment, the head-end unit 100 includes a first head-end input/output terminal 110, a second head-end input/output terminal 111 , a head-end cable terminal 112, a head-end signal separation unit 130, a head-end signal processing unit 140, a head-end downlink signal amplification unit 170, and an uplink signal division unit 180.
The first head-end input/output terminal 110 is configured to receive a first high frequency (HF) downlink signal from a base station or a repeater and transmit the first HF downlink signal to the signal processing unit 140 through a bypass line 160; and transmit a first frequency uplink signal received from the uplink signal division unit 180 to a base station or a repeater.
The second head-end input/output terminal 111 is configured to receive a second HF downlink signal which has the same physical cell identification (PCI) as the first HF downlink signal and transmit the second HF downlink signal to the head-end signal separation unit 130; and transmit a second frequency uplink signal from the head-end signal separation unit 130 to a base station or a repeater.
The head-end signal separation unit 130 is used to separate received downlink and uplink signals. Specifically, the head-end signal separation unit 130 is configured to transmit the second HF downlink signal from the second head-end input/output terminal 111 to the head-end downlink signal amplification unit 170, and transmit the second frequency uplink signal from the uplink signal division unit 180 to the second head-end input/output terminal 111.
The head-end downlink signal amplification unit 170 which is connected between the head-end signal separation unit 130 and the signal processing unit 140 is used to form a forward amplification path. The head-end downlink signal amplification unit 170 is configured to convert the second HF downlink signal into an intermediate frequency (IF) downlink signal and transmit the IF downlink signal to the head-end signal processing unit 140.
Figure 2 is a schematic diagram illustrating a head-end downlink signal amplification unit 170 according to one embodiment of the invention. In this embodiment, the downlink signal amplification unit 170 may be a heterodyne amplifier. As shown in Figure 2, the heterodyne amplifier includes an amplifier A, a forward down converter including a local oscillator B and a mixer C, an amplifier D, a filter E and an amplifier F, which are sequentially connected in series.
The head-end signal processing unit 140 is configured to combine the first HF downlink signal from the first head-end input/output terminal 110 and the IF downlink signal from the head-end downlink signal amplification unit 170, transmit the combined signals to the head-end cable terminal 112; receive an uplink signal from the head-end cable terminal 112 and transmit the received uplink signal to the uplink signal division unit 180.
The uplink signal division unit 180 is configured to divide the HF uplink signal from the head-end signal processing unit 140 into a first frequency uplink signal and a second frequency uplink signal; wherein the first frequency uplink signal is transmitted to the first head-end input/output terminal 110, and the second frequency uplink signal is transmitted to the head-end signal separation unit 130.
The head-end cable terminal 112 is installed at one side of the head-end unit 100 for connection to the single cable 200. The head-end cable terminal 112 is configured to transmit the combined signals from the head-end signal processing unit 140 to the far-end unit 300 via the single cable 200 and transmit an uplink signal from the far-end unit 300 to the head-end signal processing unit 140.
It should be noted that some components in the head-end unit 100 may be optional in other embodiments of the invention. In one example, the head-end unit may not include the head-end signal separation unit 130 and the uplink signal division unit 180 if the head- end unit is only used for downlink transmission. In another example, although the head-end unit is used for uplink transmission, the head-end unit may not include the uplink signal division unit 180, accordingly, the head-end signal separation unit 130 may be configured as an uplink band filter to transmit an uplink signal from the head-end signal processing unit 140 to the second head-end input/output terminal 111. Far-End Unit 300 (The second apparatus)
As shown in Figure 1 , the far-end unit 300 includes a first far-end input/output terminal 310, a second far-end input-output terminal 311 , a far-end cable terminal 312, a far-end signal processing unit 340, a far-end downlink signal amplification unit 370 and an output adjustment unit 390. The far-end cable terminal 312 is installed at one side of the far-end unit 300 for the connection to the single cable 200 to link up with the head-end cable terminal 112. The far- end cable terminal 312 is configured to receive a downlink signal from the head-end unit 100 through the single cable 200, and transmit an uplink signal from the far-end signal processing unit 340 to the head-end cable terminal 112 through the single cable 200. The far-end signal processing unit 340 is connected to the far-end cable terminal 312 and configured to separate the downlink signal received from the far-end cable terminal 112 of the head-end unit 100 into a first HF downlink signal and an IF downlink signal; transmit the first HF downlink signal to the first far-end input/output terminal 310 through a bypass line 360, and transmit the IF downlink signal to the far-end downlink signal amplification unit 370.
The far-end downlink signal amplification unit 370 is connected between the far-end signal processing unit 340 and the second far-end input-output terminal 311 to form a forward amplification path. The far-end downlink signal amplification unit 370 is configured to convert the IF downlink signal from the far-end signal processing unit 340 into a second HF downlink signal, and transmit the second HF downlink signal to the second far-end input-output terminal 311 .
Figure 3 is a schematic diagram showing the far-end downlink signal amplification unit 370 according to one embodiment of the invention. In this embodiment, the far-end downlink signal amplification unit 370 may be a heterodyne amplifier. As shown in Figure 3, the heterodyne amplifier includes an amplifier G, a forward up converter including a local oscillator H and a mixer I, an amplifier J, a filter K and an amplifier L, a variable attenuator M and a power amplifier N, which are sequentially connected in series. The output adjustment unit 390 is used to adjust an output power level of the second HF downlink signal from the far-end downlink signal amplification unit 370. In this embodiment, the output adjustment unit 390 may include a first detection unit 391 configured to detect a first power level of the first HF downlink signal; a second detection unit 392 configured to detect a second power level of the second HF downlink signal; and a controller 393 configured to adjust the second power level, i.e. the output power level of the second HF downlink signal, based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal. Specifically, the controller 393 may be configured to adjust the second power level of the second HF downlink signal by controlling the variable attenuator M of the far-end downlink signal amplification unit 370 based on the detected first power level.
The first far-end unit input/output terminal 310 and the second far-end input/output terminal 311 are a pair of terminals installed at one side of the far-end unit 300 to connect to any MIMO capable antennas 400 and telecom systems. The first far-end unit input/output terminal 310 is configured to transmit the first HF downlink signal from the far-end signal processing unit 340 to one or more service antennas or any telecom system; and receive uplink signals from one or more service antennas or any telecom system and transmit the received uplink signals to the far-end signal processing unit 340 through the bypass line 360. The second far-end input/output terminal 311 is configured to transmit the second
HF downlink signal from the far-end downlink signal amplification unit 370 to one or more service antennas or any telecom system; and receive uplink signals from one or more service antennas or any telecom system and transmit the received uplink signals to the far- end signal processing unit 340 through the bypass line 360. It should be noted that although in this embodiment, both of the first and the second far-end input/output terminal 310/311 are used for uplink transmission, in other embodiments, the far-end unit 300 may not be used for uplink transmission, or maybe only one of the two terminals is used for uplink transmission, e.g. the first far-end input/output terminal 310. In addition, in other embodiments, the far-end unit 300 may not include the output adjustment unit 390.
Forward path process
Downlink transmission in the head-end unit 100
Figure 4(a) is a flowchart illustrating a method 400a for MIMO downlink transmission at the head-end unit 100 according to the first embodiment of the invention.
In block 401a, the head-end unit 100 receives a first HF downlink signal through the first head-end input/output terminal 110; and receives a second HF downlink signal through the second head-end input/output terminal 111.
In block 402a, the head-end downlink signal application unit 170 in the head-end unit 100 converts the second HF downlink signal into an IF downlink signal.
In one example, the heterodyne amplifier as shown in Figure 2 may be used to convert the second HF downlink signal into the IF downlink signal.
In block 403a, the head-end signal processing unit 140 combines the first HF downlink signal and the IF downlink signal. In block 404a, the combined signals are transmitted to the far-end unit 300 through the head-end cable terminal 112 via the single cable 200.
Uplink transmission in the head-end unit 100
Figure 4(b) is a flowchart illustrating a method 400b for uplink transmission at the head-end unit 100 according to the first embodiment of the invention. In block 401b, the head-end signal processing unit 140 receives a HF uplink signal from the far-end unit 300 through the head-end cable terminal 112 via the single cable 200.
In block 402b, the uplink signal division unit 180 divides the HF uplink signal from the head-end signal processing unit 140 via a bypass line 160 into a first frequency uplink signal/part and a second frequency uplink signal/part.
In block 403b, the first frequency uplink signal is transmitted to a base station or a repeater through the first head-end input/output terminal 110; and the second frequency uplink signal is transmitted to a base station or a repeater through the second head-end input/output terminal 111. It should be noted that in other embodiments of the invention, the head-end unit 100 may not include the uplink signal division unit 180. Accordingly, the received uplink signal may be transmitted to a base station or a repeater only through the first head-end input/output terminal 110. Alternatively, the head-end signal separation unit 130 may be configured as an uplink band filter to transmit a received uplink signal from the head-end signal processing unit 140 to a base station and a repeater through the second head-end input/output terminal 111.
Backward path process
Downlink transmission in the far-end unit 300
Figure 5(a) is a flowchart illustrating a method 500a for MIMO downlink transmission at the far-end unit 300 according to the first embodiment of the invention.
In block 501a, the far-end unit 300 receives downlink signals from the head-end unit 100 through the far-end cable terminal 312 via the single cable 200.
In block 502a, the far-end signal processing unit 340 separates the received downlink signals into a first HF downlink signal and an IF downlink signal. In block 503a, the first HF downlink signal is transmitted to one or more than one service antennas or any telecom system through the first far-end unit input/output terminal 310.
In block 504a, the far-end downlink signal amplification unit 370 converts the IF downlink signal into a second HF downlink signal.
In one example, the heterodyne amplifier as shown in Figure 3 may be used to convert the IF downlink signal into the second HF downlink signal.
In block 505a, the output adjustment unit 390 detects a first power level of the first HF downlink signal transmitted to the first far-end unit input/output terminal 310 via the bypass line 360, detects a second power level of the second HF downlink signal, and adjusts the second power level of the second HF downlink signal based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
In block 506a, the second HF downlink signal is transmitted to one or more than one service antennas or any telecom system through the second far-end input/output terminal 311.
Uplink transmission in the far-end unit 300
Figure 5(b) is a flowchart illustrating a method 500b for uplink transmission at the far- end unit 100 according to the first embodiment of the invention.
In block 501 b, the far-end unit 300 receives an uplink signal through the first far-end input/output terminal 310 or the second far-end input/output terminal 311 .
In block 502b, the received uplink signal is transmitted to the far-end signal processing unit 340 via the bypass line 360.
In block 503b, the far-end signal processing unit 340 transmits the received uplink signal to the head-end unit 100 via the single cable 200. It should be noted that in some embodiments of the invention, the uplink signal may be only received through one of the first far-end input/output terminal 310 and the second far-end input/output terminal 311 .
Figure 6 is a schematic diagram showing a system 20 for MIMO transmission in a wireless communication system according to a second embodiment of the invention. In this embodiment, the system 20 includes a head-end unit 100 installed at the base station side and a plurality of far-end units 300 which are installed in the UEs side respectively. As shown in Figure 4, the head-end unit 100 is connected to the plurality of far-end units 300 via a single cable 200 and the communication between the base station and the UEs’ antennas is performed via the single cable 200.
It should be noted that the wireless communication system in embodiments of the invention may be 2G, 3G, 3.5G, 4G, 4.5G, 5G communication system or any communication system that supports usage of coaxial cable infrastructure.
As will be appreciated from the above, embodiments of the invention provide a head- end unit, a far-end unit, a system and methods for implementation of MIMO transmission in a wireless communication system. Compared with the existing solution for MIMO transmission, embodiments of the invention provide a simple system for MIMO transmission since only one cable is required for the communication between a base station and the UEs’ antennas. As such, the cost and required space for cabling installation, as well as the turn- around time for implementation of MIMO transmission are reduced significantly. For example, the solution provided by embodiments of the invention may be used to cost effectively and efficiently implement or upgrade a 5G indoor coverage using the existing coaxial cable and/or common infrastructure. It is to be understood that the embodiments and features described above should be considered exemplary and not restrictive. Many other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the invention. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. Furthermore, certain terminology has been used for the purposes of descriptive clarity, and not to limit the disclosed embodiments of the invention.

Claims

Claims
1. An apparatus for MIMO transmission in a wireless communication system, the apparatus comprising: a first head-end input/output terminal configured to receive a first high frequency (HF) downlink signal; a second head-end input/output terminal configured to receive a second HF downlink signal which have the same physical cell identification (PCI) as the first HF downlink signal; a head-end downlink signal amplification unit configured to convert the second HF downlink signal into an intermediate frequency (IF) downlink signal; a head-end signal processing unit configured to combine the first HF downlink signal and the IF downlink signal; and a head-end cable terminal configured to transmit the combined signals from the head- end signal processing unit to a far-end unit via a single cable.
2. The apparatus according to claim 1 , wherein the head-end cable terminal is further configured to receive a HF uplink signal from a far-end unit through the single cable and transmit the received HF uplink signal to the head-end signal processing unit, wherein the head-end signal processing unit is further configured to transmit the received HF uplink signal to a base station or a repeater through the first and/or the second head-end input/output terminal.
3. The apparatus according to claim 2, further comprising an uplink signal division unit configured to divide the HF uplink signal from the head-end signal processing unit into a first frequency uplink signal and a second frequency uplink signal; wherein the first frequency uplink signal is transmitted to the base station or the repeater through the first head-end input/output terminal, and the second frequency uplink signal is transmitted to the base station or the repeater through the second head-end input/output terminal.
4. The apparatus according to claim 2 or claim 3, further comprising a head-end signal separation unit configured to transmit the second HF downlink signal from the second head-end input/output terminal to the head-end downlink signal amplification unit, and transmit an uplink signal received from the head-end signal processing unit or the uplink signal division unit to the second head-end input/output terminal.
5. The apparatus according to any preceding claim, wherein the head-end downlink signal amplification unit includes a heterodyne amplifier which includes a first amplifier, a forward down converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, which are sequentially connected in series.
6. An apparatus for MIMO transmission in a wireless communication system, the apparatus comprising: a far-end cable terminal configured to receive downlink signals from a head-end unit through a single cable; a far-end signal processing unit configured to separate the downlink signals received from the far-end cable terminal into a first HF downlink signal and an IF downlink signal; a far-end downlink signal amplification unit configured to convert the IF downlink signal from the far-end signal processing unit into a second HF downlink signal; a first far-end unit input/output terminal configured to transmit the first HF downlink signal from the far-end signal processing unit to one or more service antennas or any telecom system; and a second far-end input/output terminal configured to transmit the second HF downlink signal to one or more service antennas or any telecom system.
7. The apparatus according to claim 6, further comprising an output adjustment unit configured to detect a first power level of the first HF downlink signal transmitted to the first far-end unit input/output terminal via a bypass line, detect a second power level of the second HF downlink signal from the far-end signal amplification unit and adjust the second power level based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
8. The apparatus according to claim 7, wherein the output adjustment unit includes: a first detection unit configured to detect the first power level of the first HF downlink signal; a second detection unit configured to detect the second power level of the second HF downlink signal; and a controller configured to adjust the second power level based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
9. The apparatus according to any one of claim 6 to claim 8, wherein the far-end downlink signal amplification unit includes a heterodyne amplifier which includes a first amplifier, a forward up converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, a variable attenuator and a power amplifier, which are sequentially connected in series.
10. The apparatus according to any one of claim 6 to claim 9, wherein the first far-end input/output terminal and/or the second far-end input/output terminal is further configured to receive uplink signals and transmit the received uplink signals to the far-end signal processing unit; wherein the far-end signal processing unit is further configured to transmit the uplink signals to the far-end cable terminal; and the far-end cable terminal is further configured to transmit the uplink signals to the head-end unit via the single cable.
11. A system for MIMO transmission in a wireless communication system, the system comprising: a first apparatus according to any one of claim 1 to claim 5, and at least one second apparatus according to any one of claim 6 to claim 10, wherein the communication between the first apparatus and the at least one second apparatus is conducted through a single cable.
12. The system according to claim 11 , wherein the wireless communication system includes a 2G, 3G, 3.5G, 4G, 4.5G, 5G communication system or any communication system that supports usage of coaxial cable infrastructure.
13. A method for MIMO transmission in a wireless communication system, the method comprising: receiving a first high frequency (HF) downlink signal through a first head-end input/output terminal; receiving a second HF downlink signal through a second head-end input/output terminal; converting the second HF downlink signal into an intermediate frequency (IF) downlink signal; combining the first HF downlink signal and the IF downlink signal ; and transmitting the combined signals to a far-end unit through a head-end unit cable terminal via a single cable.
14. The method according to claim 13, further comprising: receiving a HF uplink signal from the far-end unit through the head-end cable terminal via the single cable; and transmitting the received HF uplink signal to a base station or a repeater through the first and/or the second head-end input/output terminal.
15. The method according to claim 14, further comprising: before transmitting the received HF uplink signal to the base station or the repeater, dividing the received HF uplink signal into a first frequency uplink signal and a second frequency uplink signal; transmitting the first frequency uplink signal to the base station or the repeater through the first head-end input/output terminal, and transmitting the second frequency uplink signal to the base station or the repeater through the second head-end input/output terminal.
16. The method according to any one of claim 13 to claim 15, wherein the step of converting the second HF downlink signal into an IF downlink signal comprises: using a heterodyne amplifier to convert the second HF downlink signal into the IF downlink signal wherein the heterodyne amplifier includes a first amplifier, a forward down converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, which are sequentially connected in series.
17. A method for MIMO transmission in a wireless communication system, the method comprising: receiving downlink signals from a head-end unit through a far-end cable terminal via a single cable; separating the received downlink signals into a first HF downlink signal and an IF downlink signal; converting the IF downlink signal into a second HF downlink signal; transmitting the first HF downlink signal to one or more than one service antennas or any telecom system through a first far-end unit input/output terminal; and transmitting the second HF downlink signal to one or more than one service antennas or any telecom system through a second far-end input/output terminal .
18. The method according to claim 17, further comprising: detecting a first power level of the first HF downlink signal transmitted to the first far- end unit input/output terminal via a bypass line, detecting a second power level of the second HF downlink signal, and adjusting the second power level of the second HF downlink signal based on the detected first power level to synchronize the second HF downlink signal to the first HF downlink signal.
19. The method according to claim 17 or claim 18, wherein the step of converting the IF downlink signal into a second HF downlink signal comprises: using a heterodyne amplifier to convert the IF downlink signal into second HF downlink signal wherein the heterodyne amplifier includes a first amplifier, a forward up converter including a local oscillator and a mixer, a second amplifier, a filter and a third amplifier, a variable attenuator and a power amplifier, which are sequentially connected in series.
20. The method according to any one of claim 17 to claim 19, further comprising: receiving an uplink signal through the first or the second far-end input/output terminal; and transmitting the received uplink signal to the head-end unit via the single cable.
PCT/SG2019/050631 2019-12-23 2019-12-23 Apparatuses, system and methods for mimo transmission in a wireless communication system WO2021133243A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/SG2019/050631 WO2021133243A1 (en) 2019-12-23 2019-12-23 Apparatuses, system and methods for mimo transmission in a wireless communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/SG2019/050631 WO2021133243A1 (en) 2019-12-23 2019-12-23 Apparatuses, system and methods for mimo transmission in a wireless communication system

Publications (1)

Publication Number Publication Date
WO2021133243A1 true WO2021133243A1 (en) 2021-07-01

Family

ID=76574976

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SG2019/050631 WO2021133243A1 (en) 2019-12-23 2019-12-23 Apparatuses, system and methods for mimo transmission in a wireless communication system

Country Status (1)

Country Link
WO (1) WO2021133243A1 (en)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102457316A (en) * 2010-10-15 2012-05-16 中兴通讯股份有限公司 System and method for multi-antenna transmission using indoor wireless signal coverage system
KR20150054234A (en) * 2013-11-11 2015-05-20 주식회사 지에스인스트루먼트 MIMO Repeater
CN106357310A (en) * 2016-09-14 2017-01-25 京信通信系统（中国）有限公司 Multi-input multi-output signal transmission method and system
US20170149550A1 (en) * 2014-12-30 2017-05-25 Solid, Inc. Distributed antenna system for multiple input multiple output signal
EP3297314A1 (en) * 2015-06-29 2018-03-21 Huawei Technologies Co., Ltd. Distributed antenna system and signal transmission method
US20180191440A1 (en) * 2016-12-30 2018-07-05 Advanced Rf Technologies, Inc. Analog optical repeater and single optical line transmitting method for multi-band multiple-input multiple-output (mimo)
CN207677724U (en) * 2017-10-31 2018-07-31 中邮科通信技术股份有限公司 Realize a cable transmission devices of the LTE MIMO in existing room subsystem
US20190068250A1 (en) * 2016-04-29 2019-02-28 Kmw Inc. Distributed antenna system for supporting mimo service
CN109547105A (en) * 2017-09-22 2019-03-29 罗森伯格（上海）通信技术有限公司 A kind of communication equipment for realizing MIMO transmission

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102457316A (en) * 2010-10-15 2012-05-16 中兴通讯股份有限公司 System and method for multi-antenna transmission using indoor wireless signal coverage system
KR20150054234A (en) * 2013-11-11 2015-05-20 주식회사 지에스인스트루먼트 MIMO Repeater
US20170149550A1 (en) * 2014-12-30 2017-05-25 Solid, Inc. Distributed antenna system for multiple input multiple output signal
EP3297314A1 (en) * 2015-06-29 2018-03-21 Huawei Technologies Co., Ltd. Distributed antenna system and signal transmission method
US20190068250A1 (en) * 2016-04-29 2019-02-28 Kmw Inc. Distributed antenna system for supporting mimo service
CN106357310A (en) * 2016-09-14 2017-01-25 京信通信系统（中国）有限公司 Multi-input multi-output signal transmission method and system
US20180191440A1 (en) * 2016-12-30 2018-07-05 Advanced Rf Technologies, Inc. Analog optical repeater and single optical line transmitting method for multi-band multiple-input multiple-output (mimo)
CN109547105A (en) * 2017-09-22 2019-03-29 罗森伯格（上海）通信技术有限公司 A kind of communication equipment for realizing MIMO transmission
CN207677724U (en) * 2017-10-31 2018-07-31 中邮科通信技术股份有限公司 Realize a cable transmission devices of the LTE MIMO in existing room subsystem

Similar Documents

Publication Publication Date Title
US11792776B2 (en) Time-division duplexing (TDD) in distributed communications systems, including distributed antenna systems (DASs)
KR100352852B1 (en) A transmitting device of receiving signal for optical bts
EP2590441B1 (en) Base station and method for one cell to cover multiple areas
US10141985B2 (en) Determining actual loop gain in a distributed antenna system (DAS)
US20160249365A1 (en) Offsetting unwanted downlink interference signals in an uplink path in a distributed antenna system (das)
US20100041341A1 (en) Method and apparatus for determining an end of a subframe in a tdd system
CN106357310B (en) Multiple input multiple output signal transmission method and system
US11483057B2 (en) Base station signal matching device, and base station interface unit and distributed antenna system including the same
CN107211484A (en) Symmetrical and full duplex relaying device in wireless system
CN102664683A (en) Remote signal processing method and remote unit used in remote optical fiber type wireless distribution systems
KR101282070B1 (en) Mimo repeater
CN209949102U (en) Low-intermodulation multi-system combiner
WO2021133243A1 (en) Apparatuses, system and methods for mimo transmission in a wireless communication system
EP2733976A1 (en) System, device, and method for transmitting multi-input-multi-output signals
US20180316457A1 (en) Methods and Apparatus for Multiplexing and Demultiplexing Signals
US12088364B2 (en) Wireless communication apparatus, antenna detection method and user device
CN110324064B (en) Low intermodulation multi-system combiner
JP2019216366A (en) Wireless communication device and wireless communication method
JP2012222379A (en) Radio communication device and radio communication method for performing transmission power control
US20180213419A1 (en) Channel simulator having function of supporting carrier aggregation and carrier aggregation block used for the same
KR20120001047A (en) Mobile communication repeater system and integrated line repeater
WO2015156508A1 (en) Filter for relaying apparatus of mobile communication system
US20220360318A1 (en) Radio communication apparatus, and radio communication method
KR101542551B1 (en) An apparatus for controlling delay of remote optical unit for wireless communication and the method thereof
CN115967966A (en) Relay coverage system and multi-channel time delay balancing method thereof

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19957058

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19957058

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 03/11/2022)

122 Ep: pct application non-entry in european phase

Ref document number: 19957058

Country of ref document: EP

Kind code of ref document: A1