A satellite communication system and method based on 5G technology

Abstract

The present invention discloses a satellite communication system and method based on 5G technology, belonging to the field of satellite communication technology. The signals transmitted by the system in both uplink and downlink are based on a continuous wireless frame structure. Each wireless frame includes several subframes with a length of 1ms. Each subframe includes N time slots. Each time slot includes several symbols, and the symbols are all modulated using a single carrier. In the signal transmitted downlink by the system, the time slot is a downlink time slot. The downlink time slot includes a control symbol for transmitting control information and several data symbols for transmitting data information. The control symbol is divided into K control information blocks according to the frequency band. Each control information block is an independent single-carrier signal. In the signal transmitted uplink by the system, the time slot is an uplink time slot, and the symbols in the uplink time slot are all data symbols. The present invention adopts a single-carrier waveform, thereby reducing the signal peak-to-average ratio, improving the efficiency of the satellite power amplifier, improving the power consumption and heat generation performance of the satellite, and enhancing the satellite data communication capability.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a satellite communication system and method based on 5G technology. Background Art

[0002] Compared to terrestrial mobile communication networks, satellite communication systems can achieve wide-area, even global, coverage, providing undifferentiated communication services to users worldwide. Furthermore, terrestrial fifth-generation mobile communication (5G) systems already possess a well-developed industrial chain, a vast user base, and flexible and efficient application service models. The integration of satellite communication and 5G, leveraging their strengths and complementing their weaknesses, will together form a seamless, integrated global communication network covering land, sea, air, and space, meeting the diverse service needs of users everywhere. This represents a key direction for future communications development.

[0003] The frame structure of the ground 5G system is as follows Figure 1 As shown in Figure 1, both downlink and uplink signals are based on a continuous radio frame structure. Each radio frame is 10ms long and can be divided into 10 subframes of 1ms each. Each subframe contains N time slots, where the value of N is related to the system bandwidth. Each time slot can be divided into 14 symbols, each of which is an OFDM waveform. The first few symbols in a single time slot are control information, and the remaining symbols are data. Each user's data is distinguished by the frequency domain and occupies a specific frequency domain position (PRB) of all data symbols, as shown in Figure 1. Figure 2 shown.

[0004] OFDM waveforms have the characteristics of high transmission efficiency and effective resistance to multipath fading, and have been widely used in wireless communication systems such as wireless LANs and 4G / 5G. However, one of the main disadvantages of OFDM systems is their large peak-to-average power ratio (PAPR), which directly affects the operating cost and efficiency of the entire system. When the peak-to-average power ratio is large, the power amplifier, A / D, and D / A converter must have a large linear dynamic range. Otherwise, when the signal peak enters the nonlinear region of the amplifier, the signal will be distorted, causing intermodulation interference and out-of-band radiation between subcarriers, destroying the orthogonality between subcarriers, and reducing system performance. To avoid this, a common method is to use a power amplifier with a large dynamic range or to compensate the operating point of the power amplifier. However, doing so will greatly reduce the efficiency of the power amplifier, and most of the energy will be converted into heat and wasted.

[0005] Unlike terrestrial cellular networks, satellites have limited power resources. To maximize throughput under given transmit power conditions, power amplifiers must operate near saturation. 5G transmission links use OFDM waveforms, which have a high peak-to-average ratio. Directly using 5G signal waveforms in satellite transmission links reduces power amplifier efficiency and introduces heat dissipation issues. Therefore, minimizing the peak-to-average ratio while maintaining high bandwidth utilization is a key issue in the design of converged signal systems for 5G and satellite communications. Summary of the Invention

[0006] In view of the problem that the OFDM waveform used in the ground 5G system transmission link in the existing technology has a high peak-to-average ratio, which will lead to reduced power amplifier efficiency and greater heat dissipation when applied to satellite transmission links. The purpose of the present invention is to provide a satellite communication system and method based on 5G technology, so as to at least partially solve the above problems.

[0007] To achieve the above object, the technical solution of the present invention is:

[0008] In a first aspect, the present invention provides a satellite communication system based on 5G technology, wherein both uplink and downlink signals transmitted by the system are based on a continuous radio frame structure, each radio frame includes a plurality of subframes with a length of 1 ms, each subframe includes N time slots, each time slot includes a plurality of symbols, and each symbol is modulated using a single carrier.

[0009] Among them, the time slot in the signal sent in the downlink of the system is a downlink time slot, and the downlink time slot includes a control symbol for transmitting control information and a number of data symbols for transmitting data information. The control symbol is divided into K control information blocks according to the frequency band, and each of the control information blocks is an independent single-carrier signal; the time slot in the signal sent in the uplink of the system is an uplink time slot, and the symbols in the uplink time slot are all data symbols.

[0010] In a preferred embodiment, each of the radio frames includes 10 subframes with a length of 1 ms; each of the time slots includes 14 symbols, and the first symbol in the downlink time slot is the control symbol.

[0011] In a preferred embodiment, several data symbols in the downlink time slot correspond to one or more terminals. When there are multiple corresponding terminals, the correspondence between the data symbols and the terminals is indicated by K control information blocks in the control symbol.

[0012] In a preferred embodiment, each control information block in the downlink time slot is scrambled by the C-RNTI of the corresponding terminal, so that each terminal uses its own C-RNTI to descramble the corresponding information control block in each downlink time slot.

[0013] In a preferred embodiment, the number K of control information blocks in the downlink time slot is sent to all terminals in a system message in a broadcasting manner.

[0014] In a preferred embodiment, the control information block carries a downlink scheduling grant or an uplink scheduling grant.

[0015] In a preferred embodiment, the downlink scheduling grant and the uplink scheduling grant include the total number of data information blocks allocated to the terminal, the starting data information block position, the modulation mode, and the code rate; wherein each of the data symbols includes several data information blocks.

[0016] In a second aspect, the present invention further provides a satellite communication method based on 5G technology, which is applied to the system as described above, comprising the following steps:

[0017] The satellite indicates to the terminal the number K of control information blocks contained in the downlink time slot through a system message;

[0018] The terminal uses its own C-RNTI to descramble K control information blocks in the control symbol in each downlink time slot;

[0019] If all control information blocks fail to be descrambled, the terminal skips the current downlink time slot; for control information blocks that are successfully descrambled, the terminal operates on subsequent data symbols according to instructions of the control information blocks.

[0020] In a preferred embodiment, for a control information block that is successfully descrambled, if the descrambled information block is a downlink scheduling authorization, the terminal demodulates the downlink data from the data symbols of the current downlink time slot according to the indication of the downlink scheduling authorization; if the descrambled information block is an uplink scheduling authorization, the terminal sends uplink data in the data symbols of the subsequent uplink time slot according to the indication of the uplink scheduling authorization.

[0021] By adopting the above technical solution, the beneficial effect of the present invention is that: the technical solution of the present invention continues to use the 5G technology framework, but on this basis does not use the original OFDM waveform of 5G, but adopts a single carrier waveform, thereby reducing the signal peak-to-average ratio, improving the efficiency of the satellite power amplifier, improving the satellite's power consumption and heat generation performance, and improving the satellite's data communication capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the frame structure of a terrestrial 5G system in the prior art;

[0023] Figure 2 Schematic diagram of the time slot structure of the terrestrial 5G system in the prior art;

[0024] Figure 3 Schematic diagram of the time slot structure in embodiment 1 of the present invention;

[0025] Figure 4 This is a flow chart of the method in embodiment 2 of the present invention. DETAILED DESCRIPTION

[0026] The following is a further description of specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0027] It should be noted that, in the description of the present invention, the terms "up", "down", "left", "right", "front", "back", etc. indicating directions or positional relationships are based on the description of the structure of the present invention shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, it cannot be understood as a limitation on the present invention.

[0028] The "first" and "second" in this technical solution are only used to distinguish the same or similar structures, or corresponding structures with similar functions, and are not an arrangement of the importance of these structures, nor do they have any ranking, size comparison, or other meanings.

[0029] In addition, unless otherwise expressly specified or limited, the terms "installed" and "connected" should be understood broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be internal communication between two structures. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on the overall principles of the present invention and the specific context of this solution.

[0030] Example 1

[0031] A satellite communication system based on 5G technology, in which the uplink and downlink signals sent by the system are based on a continuous wireless frame structure, such as Figure 1 As shown, this embodiment is similar to existing terrestrial 5G systems. Each radio frame consists of 10 1ms subframes, each containing N time slots, where N is related to the system bandwidth. Each time slot contains 14 symbols. Compared to existing terrestrial 5G systems, this embodiment also differs in that the symbols in the time slots are modulated using a single carrier.

[0032] Among them, in the downlink signal sent by the system (the signal sent by the satellite to the terminal), the time slot is called the downlink time slot. The downlink time slot includes 1 control symbol for transmitting control information and 13 data symbols for transmitting data information. The first symbol in the downlink time slot is the control symbol. The control symbol is divided into K control information blocks according to the frequency band, and each control information block is an independent single-carrier signal, such as Figure 3 In the uplink signal sent by the system (the signal sent by the terminal to the satellite), the time slot is called the uplink time slot, and the 14 symbols in the uplink time slot are all data symbols.

[0033] In a downlink timeslot, the 13 data symbols can correspond to a single terminal or multiple terminals (i.e., the 13 data symbols can be sent to different terminals). When there are multiple terminals, the correspondence between the data symbols and the terminals is indicated by the K control information blocks in the control symbol. The number of control information blocks K in a downlink timeslot is broadcast to all terminals in a system message.

[0034] For example, each control information block in a downlink time slot is scrambled by the C-RNTI of the corresponding terminal, so that each terminal descrambles the corresponding information control block using its own C-RNTI in each downlink time slot.

[0035] The control information block carries a downlink scheduling grant or an uplink scheduling grant. These grants include the total number of data blocks allocated to the terminal, the starting data block location, the modulation scheme, and the bit rate. Each data symbol contains several data blocks. Specifically, a downlink scheduling grant indicates which data blocks in the current downlink timeslot are allocated to the terminal for data download; an uplink scheduling grant indicates which data blocks in subsequent uplink timeslots the terminal should use to upload data.

[0036] Example 2

[0037] A satellite communication method based on 5G technology is applied to the system disclosed in Example 1, such as Figure 4 As shown, the following steps are included:

[0038] The satellite indicates to the terminal the number K of control information blocks contained in the downlink time slot through a system message;

[0039] The terminal uses its own C-RNTI to descramble K control information blocks in the control symbol in each downlink time slot;

[0040] If all control information blocks fail to be descrambled, the terminal skips the current downlink time slot; for control information blocks that are successfully descrambled, the terminal operates on subsequent data symbols according to the instructions of the control information blocks.

[0041] Specifically, for the control information block that is successfully descrambled, if the descrambled result is a downlink scheduling authorization, the terminal demodulates the downlink data from the data symbol of the current downlink time slot according to the instructions of the downlink scheduling authorization; if the descrambled result is an uplink scheduling authorization, the terminal sends the uplink data in the data symbol of the subsequent uplink time slot according to the instructions of the uplink scheduling authorization.

[0042] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations to these embodiments may be made without departing from the principles and spirit of the present invention, and these changes and modifications still fall within the scope of protection of the present invention.

Claims

1. A satellite communication system based on 5G technology, characterized by: The uplink and downlink signals transmitted by the system are based on a continuous radio frame structure, each radio frame includes several subframes with a length of 1 ms, each subframe includes N time slots, each time slot includes several symbols, and the symbols are modulated using a single carrier; The time slot in the signal transmitted in the downlink of the system is a downlink time slot, and the downlink time slot includes a control symbol for transmitting control information and a plurality of data symbols for transmitting data information. The control symbol is divided into K control information blocks according to the frequency band, and each control information block is an independent single-carrier signal. The time slot in the signal transmitted in the uplink of the system is an uplink time slot, and the symbols in the uplink time slot are all data symbols. Each of the radio frames includes 10 subframes with a length of 1 ms; each of the time slots includes 14 of the symbols, and the first symbol in the downlink time slot is the control symbol; Several data symbols in the downlink time slot correspond to one or more terminals. When there are multiple corresponding terminals, the correspondence between the data symbols and the terminals is indicated by K control information blocks in the control symbol.

2. The system according to claim 1, wherein: Each control information block in the downlink time slot is scrambled by the C-RNTI of the corresponding terminal, so that each terminal uses its own C-RNTI to descramble the corresponding information control block in each downlink time slot.

3. The system according to claim 2, characterized in that: The number K of control information blocks in the downlink time slot is sent to all terminals in a system message in a broadcasting manner.

4. The system according to claim 2, wherein: The control information block carries a downlink scheduling grant or an uplink scheduling grant.

5. The system according to claim 4, characterized in that: The downlink scheduling grant and the uplink scheduling grant include the total number of data information blocks allocated to the terminal, the starting data information block position, the modulation mode, and the code rate; wherein each of the data symbols includes a plurality of data information blocks.

6. A satellite communication method based on 5G technology, applied to the system according to any one of claims 1 to 5, characterized in that: The following steps are involved: The satellite indicates to the terminal the number K of control information blocks contained in the downlink time slot through a system message; The terminal uses its own C-RNTI to descramble K control information blocks in the control symbol in each downlink time slot; If all control information blocks fail to be descrambled, the terminal skips the current downlink time slot; for control information blocks that are successfully descrambled, the terminal operates on subsequent data symbols according to instructions of the control information blocks.

7. The method according to claim 6, characterized in that: For the control information block that is successfully descrambled, if the descrambled result is a downlink scheduling authorization, the terminal demodulates the downlink data from the data symbols of the current downlink time slot according to the instructions of the downlink scheduling authorization; if the descrambled result is an uplink scheduling authorization, the terminal sends uplink data in the data symbols of the subsequent uplink time slot according to the instructions of the uplink scheduling authorization.

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