5G uplink low-power-consumption repeated transmission method

Abstract

The invention discloses a 5G uplink low-power-consumption repeated transmission method, and relates to the technical field of communication, in a 5G Redcap system, on the premise that uplink retransmission based on a linear programming method in the patent meets the uplink bit error rate requirement, signal transmission is carried out at the power as low as possible, the power consumption of a terminal is saved as far as possible, which is of great significance to the energy conservation of the terminal with limited battery energy consumption, and the method is worthy of popularization and application. Such equipment as an inspection unmanned aerial vehicle in an electric power scene.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and in particular to a 5G uplink low-power consumption repeated transmission method. Background Art

[0002] Since 5G NR is used to support various scenarios such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), and massive machine type communications (mMTC), 5G NR is very flexible compared to 4G LTE. However, a key issue of the 5G NR system is its limited coverage, because 5G NR uses higher frequency bands to support wider bandwidths and inevitably suffers from greater path loss in these frequency bands]. Therefore, coverage enhancement is one of the key design factors that need to be considered for the 5G NR system, and this feature has been standardized as part of the 3GPP R17 5G specification. In R17, the coverage performance of various channels and signals used for 5G NR was evaluated to verify the coverage requirements of the 5G-NR system. The evaluation results show that PUSCH (uplink shared channel) is the uplink coverage bottleneck. R17 supports three main coverage enhancement schemes, such as PUSCH repetition enhancement, TB (transport block) processing on multi-slot PUSCH, and joint channel estimation.

[0003] PUSCH repeated transmission is an important means of enhancing uplink coverage. Figure 1 As shown, assuming that a frame has 20 time slots, the base station can configure 6 repeated transmissions for the terminal in time slots #5, #9, #10, #15, #19 and #20, so as to obtain diversity gain brought by repeated transmission and improve uplink coverage performance.

[0004] However, the transmission power used by the terminal for retransmission during uplink retransmission depends on the specific implementation. If each time slot is retransmitted at the maximum power, the base station may obtain a receiving equivalent signal-to-noise ratio that is much higher than the target signal-to-noise ratio of the signal that can actually be demodulated through receiving and combining, which will lead to power waste of the terminal. Obviously, the ideal transmission power of the terminal is to make the receiving equivalent signal-to-noise ratio of the uplink signal equal to the target signal-to-noise ratio of the signal that can be demodulated after combining at the base station.

[0005] In the 5G R17 Redcap protocol, in order to increase the uplink coverage distance, the repeated transmission of the uplink shared channel PUSCH is supported, and up to 32 uplink retransmissions are supported. During the uplink repeated transmission process, the transmit power used by the terminal for retransmission depends on the specific implementation. If each time slot is repeatedly transmitted at the maximum power, the base station may obtain a received equivalent signal-to-noise ratio that is much larger than the signal-to-noise ratio that can be demodulated through receiving and combining, resulting in power waste of the terminal. Obviously, the ideal transmit power of the terminal is just enough to make the uplink signal after combining at the base station, and its received equivalent signal-to-noise ratio is equal to the target signal-to-noise ratio that can be demodulated. Summary of the invention

[0006] In order to overcome the shortcomings of the above technologies, the present invention provides a 5G uplink low-power repeated transmission method which transmits signals at the lowest possible power and saves terminal power consumption as much as possible while meeting the uplink bit error rate requirements.

[0007] The technical solution adopted by the present invention to overcome the technical problems is:

[0008] A 5G uplink low-power repeated transmission method, comprising:

[0009] S1. The base station allocates S uplink time slots for retransmission to the terminal, and the i-th uplink time slot is s i , the uplink time slot set is Π, Π={s1,s2,...,s i ,...,s S};

[0010] S2. The base station obtains the i-th historical uplink time slot s′ i ;

[0011] S3. The base station measures and obtains the i-th historical uplink time slot s′ i Signal-to-noise ratio And notify the terminal;

[0012] S4. The terminal is based on the signal-to-noise ratio Calculate the signal-to-noise ratio of the retransmitted i-th uplink retransmission time slot si

[0013] S5. The base station calculates the baseband signal Y after each receiving antenna combines the S uplink time slot signals assigned to the terminal for retransmission m ;

[0014] S6. The terminal calculates the average output signal-to-noise ratio snr of the retransmitted S uplink time slots eff ;

[0015] S7. The terminal outputs the average signal-to-noise ratio snr of the retransmitted S uplink time slots effand P is the maximum terminal transmission power P. Solve the linear programming to obtain the terminal transmission power of the i-th uplink time slot si

[0016] S8. The baseband signal Y after merging the S uplink time slot signals retransmitted by the terminal according to each receiving antenna m , the i-th uplink time slot s i The terminal transmission power Calculate the final signal on the subcarrier

[0017] Furthermore, in step S2, the historical uplink time slot set of the base station is Ω, Ω = {s′1, s′2, ..., s′ i ,...,s′ N}, N is the number of historical uplink time slots.

[0018] Furthermore, in step S3, the formula

[0019] Calculate the i-th historical uplink time slot s′ i Signal-to-noise ratio

[0020] Where:

[0021] σ 2 is the received signal noise power at the base station;

[0022] The i-th historical uplink time slot s′ of the base station at the j-th base station receiving antenna i The frequency domain channel response at the mth uplink signal subcarrier;

[0023] j∈{1,2,...,N R},N R is the number of receiving antennas, m∈{1,2,...,M}, M is the number of uplink signal subcarriers;

[0024] |·| is used to obtain the absolute value.

[0025] Further, in step S4, the formula

[0026] Calculate the i-th uplink time slot s i Signal-to-noise ratio

[0027] Where:

[0028] interp1(·) is the interp1 function of Matlab.

[0029] Further, in step S5, the formula

[0030] The baseband signal Y after each receiving antenna combines the S uplink time slot signals assigned to the terminal for retransmission is calculated. m ;

[0031] Where:

[0032] is the i-th uplink time slot s i An uplink frequency channel response vector at the mth uplink signal subcarrier;

[0033]

[0034] is the i-th uplink time slot s i The terminal transmit power;

[0035] is the i-th uplink time slot s i The weighting coefficient of

[0036] is the i-th uplink time slot s i The channel matrix at the mth uplink signal subcarrier,

[0037]

[0038] is the i-th uplink time slot s i The channel frequency domain response of the jth receiving antenna port at the mth uplink signal subcarrier;

[0039] is the i-th uplink time slot s i The received signal vector at the mth uplink signal subcarrier is:

[0040] is the i-th uplink time slot s i The received signal vector of the j-th receiving antenna port at the m-th uplink signal subcarrier;

[0041]

[0042] is the i-th uplink time slot s i The jth zero mean value at the mth uplink signal subcarrier, the zero mean value set is

[0043] Further, in step S6, the formula

[0044] Calculate the average output signal-to-noise ratio snr of the retransmitted S uplink time slots eff ;

[0045] Where:

[0046] is the i-th uplink time slot s i The terminal transmit power.

[0047] Further, the linear programming is solved in step S7 as follows;

[0048]

[0049] Where:

[0050] snr tar The target signal-to-noise ratio is obtained by simulating the MCS demodulation performance of the transmitted service using Matlab software;

[0051] T is transpose;

[0052] P is the maximum transmit power of the terminal.

[0053] Further, in step S8, the formula

[0054] Calculate the final signal on the subcarrier

[0055] In the formula is the terminal estimated by the base station in the i-th uplink time slot s i The transmit power on.

[0056] Furthermore, through the formula

[0057] Calculate the terminal estimated by the base station in the i-th uplink time slot s i Transmit power on

[0058] Where E(·) is the mean;

[0059] Q m′ is the pilot defined by the 3GPP Redcap protocol;

[0060] is the i-th uplink time slot s i The received signal vector at the m′th pilot subcarrier is:

[0061]

[0062] The i-th uplink time slot s iThe received signal vector of the jth receiving antenna port at the m′th subcarrier where the pilot is placed;

[0063]

[0064] is the i-th uplink time slot s i The channel matrix at the m′th subcarrier where the pilot is placed,

[0065] is the i-th uplink time slot s i The channel frequency domain response of the jth receiving antenna port at the m′th subcarrier where the pilot is placed;

[0066] is the i-th uplink time slot s i The jth zero mean value at the m′th pilot subcarrier, the zero mean value set is Furthermore, through the formula Calculate the i-th uplink time slot s i Channel frequency domain response of the jth receiving antenna port at the m′th pilot subcarrier By formula

[0067] Calculate the i-th uplink time slot s i Channel frequency domain response of the jth receiving antenna port at the mth uplink signal subcarrier

[0068] The beneficial effect of the present invention is that in the 5G Redcap system, the uplink retransmission based on the linear programming method in this patent is used to transmit signals at the lowest possible power while meeting the uplink bit error rate requirements, thereby saving terminal power consumption as much as possible. This is of great significance for energy saving of terminals with limited battery power consumption, such as inspection drones and other equipment in power scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 Schematic diagram of repeated transmission of PUSCH;

[0070] Figure 2 is a flow chart of the method of the present invention;

[0071] Figure 3 It is a simulation frame structure diagram of the present invention;

[0072] Figure 4 It is a simulation diagram of the bit error rate and throughput of the present invention;

[0073] Figure 5 is a graph showing the relationship between the input signal-to-noise ratio and the output signal-to-noise ratio of the present invention;

[0074] Figure 6 The transmit power diagram of each time slot calculated by the present invention;

[0075] Figure 7 This is a performance diagram of retransmission according to the calculated transmission power of the present invention. DETAILED DESCRIPTION

[0076] The following is combined with Figure 1 To Attachment Figure 7 The present invention is further described.

[0077] As attached Figure 2 A 5G uplink low-power repeated transmission method is shown, comprising:

[0078] S1. The base station allocates S uplink time slots for retransmission to the terminal, and the i-th uplink time slot is s i , the uplink time slot set is Π, Π={s1,s2,...,s i ,...,s S}.

[0079] S2. The base station obtains the i-th historical uplink time slot s′ i .

[0080] S3. The base station measures and obtains the i-th historical uplink time slot s′ i Signal-to-noise ratio And notify the terminal.

[0081] S4. The terminal is based on the signal-to-noise ratio Calculate the i-th uplink retransmission time slot s for retransmission i Signal-to-noise ratio

[0082] S5. The base station calculates the baseband signal Y after each receiving antenna combines the S uplink time slot signals assigned to the terminal for retransmission m .

[0083] S6. The terminal calculates the average output signal-to-noise ratio snr of the retransmitted S uplink time slots eff .

[0084] S7. The terminal outputs the average signal-to-noise ratio snr of the retransmitted S uplink time slots eff and P is the maximum transmission power of the terminal. Solve the linear programming and get the i-th uplink time slot s i The terminal transmission power

[0085] S8. The baseband signal Y after merging the S uplink time slot signals retransmitted by the terminal according to each receiving antenna m , the terminal transmission power of the i-th uplink time slot si Calculate the final signal on the subcarrier

[0086] Under the premise of meeting the uplink bit error rate requirements, signal transmission is carried out at the lowest possible power to save terminal power consumption as much as possible.

[0087] In one embodiment of the present invention, the historical uplink time slot set of the base station in step S2 is Ω, Ω = {s′1, s′2, ..., s′ i ,...,s′ N}, N is the number of historical uplink time slots.

[0088] In one embodiment of the present invention, in step S3, the formula Calculate the i-th historical uplink time slot s′ i Signal-to-noise ratio

[0089] Where:

[0090] σ 2 is the received signal noise power at the base station;

[0091] The i-th historical uplink time slot s′ of the base station at the j-th base station receiving antenna i The frequency domain channel response at the mth uplink signal subcarrier;

[0092] j∈{1,2,...,N R},N R is the number of receiving antennas, m∈{1,2,...,M}, M is the number of uplink signal subcarriers;

[0093] |·| is used to obtain the absolute value.

[0094] In one embodiment of the present invention, in step S4, the formula Calculate the i-th uplink retransmission time slot s i Signal-to-noise ratio Signal-to-Noise Ratio Inform the terminal;

[0095] Where:

[0096] interp1(·) is the interp1 function of Matlab.

[0097] In one embodiment of the present invention, in step S5, the formula

[0098] The baseband signal Y after each receiving antenna combines the S uplink time slot signals assigned to the terminal for retransmission is calculated. m ;

[0099] Where:

[0100] is the i-th uplink time slot s i An uplink frequency channel response vector at the mth uplink signal subcarrier;

[0101]

[0102] is the i-th uplink time slot s i The terminal transmit power;

[0103] is the i-th uplink time slot s i The weighting coefficient of

[0104] is the i-th uplink time slot s i The channel matrix at the mth uplink signal subcarrier,

[0105]

[0106] is the i-th uplink time slot s i The channel frequency domain response of the jth receiving antenna port at the mth uplink signal subcarrier;

[0107] is the i-th uplink time slot s i The received signal vector at the mth uplink signal subcarrier is:

[0108] is the i-th uplink time slot s i The received signal vector of the j-th receiving antenna port at the m-th uplink signal subcarrier;

[0109]

[0110] is the i-th uplink time slot s i The jth zero mean value at the mth uplink signal subcarrier, the zero mean value set is

[0111] In one embodiment of the present invention, in step S6, the formula Calculate the average output signal-to-noise ratio snr of the retransmitted S uplink time slots eff ;

[0112] Where:

[0113] is the i-th uplink time slot s i The terminal transmit power.

[0114] In one embodiment of the present invention, solving the linear programming in step S7 is:

[0115]

[0116] Where:

[0117] snr tar The target signal-to-noise ratio is obtained by simulating the MCS demodulation performance of the transmitted service using Matlab software;

[0118] T is transpose;

[0119] P is the maximum transmit power of the terminal.

[0120] In one embodiment of the present invention, in step S8, the formula Calculate the final signal on the subcarrier In the formula is the terminal estimated by the base station in the i-th uplink time slot s i The transmit power on.

[0121] In one embodiment of the present invention, by formula Calculate the terminal estimated by the base station in the i-th uplink time slot s i Transmit power on

[0122] Where E(·) is the mean;

[0123] Q m′ is the pilot defined by the 3GPP Redcap protocol;

[0124] is the i-th uplink time slot s i The received signal vector at the m′th pilot subcarrier is:

[0125]

[0126] The i-th uplink time slot s i The received signal vector of the jth receiving antenna port at the m′th subcarrier where the pilot is placed;

[0127]

[0128] is the i-th uplink time slot s i The channel matrix at the m′th subcarrier where the pilot is placed,

[0129] is the i-th uplink time slot s i The channel frequency domain response of the jth receiving antenna port at the m′th subcarrier where the pilot is placed;

[0130] is the i-th uplink time slot s i The jth zero mean value at the m′th pilot subcarrier, the zero mean value set is In one embodiment of the present invention, by formula Calculate the i-th uplink time slot s i Channel frequency domain response of the jth receiving antenna port at the m′th pilot subcarrier

[0131] By formula

[0132] Calculate the i-th uplink time slot s i Channel frequency domain response of the jth receiving antenna port at the mth uplink signal subcarrier This section simulates and compares the benefits of the uplink low-power retransmission power compared to the maximum transmission power when the present invention is adopted. The system simulation parameter settings are shown in Table 1:

[0133] Table 1 System simulation parameter configuration

[0134]

[0135] The simulation uses a 10ms frame structure and the configuration is as shown in the attached Figure 3 As shown, D stands for downlink, U stands for uplink, and S stands for flexible time slot:

[0136] To evaluate the performance of power allocation based on linear programming, it is assumed that the uplink signal-to-noise ratio γ of the terminal is known ideally. s The simulation results are shown in the attached Figure 4 As shown, attached Figure 4 The figure represents the RAW-BER before decoding, the BER after decoding, and the normalized throughput simulation results under different input signal-to-noise ratios. The larger the input signal-to-noise ratio, the closer the terminal is to the base station when the base station noise power is fixed, and the greater the power of the uplink transmission signal when it reaches the base station. The input signal-to-noise ratio refers to the signal-to-noise ratio before merging multiple uplink time slots: It can be seen that when snr in =3dB, the RAW-BER is 0.012, the BER is reduced to below 1e-4, and the throughput reaches more than 99.9%.

[0137] Attached Figure 5 is the snr obtained by simulation in With SNR eff relationship, snr in=3dB, the corresponding snr eff =11dB. Therefore, snr tar =11dB.

[0138] Attached Figure 6 The transmission power of each time slot obtained by the present invention under different input signal-to-noise ratios is shown in the simulation. The larger the input signal-to-noise ratio, that is, the closer the terminal is to the base station, the smaller the required transmission power is. in =12dB, the actual transmit power is 31.5% of the maximum transmit power.

[0139] Attached Figure 7 The uplink performance of the retransmission time slot under different input signal-to-noise ratios is shown in the figure. The simulation shows that under different input signal-to-noise ratios, the RAW-BER is around 0.01 and the throughput is above 99.9%, meeting the uplink transmission performance target. Figure 6 As shown in snr in =3dB, the transmission power is 82% of the maximum power, at snr in =12dB, the transmission power is 31.5% of the maximum power, and the energy saving gain is obvious.

[0140] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A 5G uplink low-power repeated transmission method, characterized in that: include: S1. The base station allocates S uplink time slots for retransmission to the terminal, and the i-th uplink time slot is s i , the uplink time slot set is Π, Π={s1,s2,...,s i ,...,s S }; S2. The base station obtains the i-th historical uplink time slot s′ i ; S3. The base station measures and obtains the i-th historical uplink time slot s′ i Signal-to-noise ratio And notify the terminal; S4.Base station based on signal-to-noise ratio Calculate the i-th uplink retransmission time slot s for retransmission i Signal-to-noise ratio S5. The base station calculates the baseband signal Y after each receiving antenna combines the S uplink time slot signals assigned to the terminal for retransmission m ; S6. The terminal calculates the average output signal-to-noise ratio snr of the retransmitted S uplink time slots eff ; S7. The terminal outputs the average signal-to-noise ratio snr of the retransmitted S uplink time slots eff and P is the maximum transmission power of the terminal. Solve the linear programming and get the i-th uplink time slot s i The terminal transmission power S8. The baseband signal Y after merging the S uplink time slot signals retransmitted by the terminal according to each receiving antenna m , the i-th uplink time slot s i The terminal transmission power Calculate the final signal on the subcarrier 2. The 5G uplink low-power repeated transmission method according to claim 1, characterized in that: In step S2, the historical uplink time slot set of the base station is Ω, Ω = {s′1, s′2, ..., s′ i ,...,s′ N }, N is the number of historical uplink time slots.

3. The 5G uplink low-power repeated transmission method according to claim 1, characterized in that: In step S3, the formula Calculate the i-th historical uplink time slot s′ i Signal-to-noise ratio Where: σ 2 is the received signal noise power at the base station; The i-th historical uplink time slot s′ of the base station at the j-th base station receiving antenna i The frequency domain channel response at the mth uplink signal subcarrier; j∈{1,2,...,N R },N R is the number of receiving antennas, m∈{1,2,...,M}, M is the number of uplink signal subcarriers; ··|To obtain the absolute value.

4. The 5G uplink low-power repeated transmission method according to claim 1, characterized in that: In step S4, the formula Calculate the i-th uplink time slot s i Signal-to-noise ratio Where: interp1(·) is the interp1 function of Matlab.

5. The 5G uplink low-power repeated transmission method according to claim 3, characterized in that: In step S5, the formula The baseband signal Y after each receiving antenna combines the S uplink time slot signals assigned to the terminal for retransmission is calculated. m ; Where: is the i-th uplink time slot s i An uplink frequency channel response vector at the mth uplink signal subcarrier; is the i-th uplink time slot s i The terminal transmit power; is the i-th uplink time slot s i The weighting coefficient of is the i-th uplink time slot s i The channel matrix at the mth uplink signal subcarrier, is the i-th uplink time slot s i The channel frequency domain response of the jth receiving antenna port at the mth uplink signal subcarrier; is the i-th uplink time slot s i The received signal vector at the mth uplink signal subcarrier is: is the i-th uplink time slot s i The received signal vector of the j-th receiving antenna port at the m-th uplink signal subcarrier; is the i-th uplink time slot s i The jth zero mean value at the mth uplink signal subcarrier, the zero mean value set is 6. The 5G uplink low-power repeated transmission method according to claim 3, characterized in that: In step S6, the formula Calculate the average output signal-to-noise ratio snr of the retransmitted S uplink time slots eff ; Where: is the i-th uplink time slot s i The terminal transmit power.

7. The 5G uplink low-power repeated transmission method according to claim 6, characterized in that: The linear programming solution in step S7 is: Where: snr tar The target signal-to-noise ratio is obtained by simulating the MCS demodulation performance of the transmitted service using Matlab software; T is transpose; P is the maximum transmit power of the terminal.

8. The 5G uplink low-power repeated transmission method according to claim 5, characterized in that: In step S8, the formula Calculate the final signal on the subcarrier In the formula is the terminal estimated by the base station in the i-th uplink time slot s i The transmit power on.

9. The 5G uplink low-power repeated transmission method according to claim 8, characterized in that: By formula Calculate the terminal estimated by the base station in the i-th uplink time slot s i Transmit power on Where E(·) is the mean; Q m′ is the pilot defined by the 3GPP Redcap protocol; is the i-th uplink time slot s i The received signal vector at the m′th pilot subcarrier is: The i-th uplink time slot s i The received signal vector of the jth receiving antenna port at the m′th subcarrier where the pilot is placed; is the i-th uplink time slot s i The channel matrix at the m′th subcarrier where the pilot is placed, is the i-th uplink time slot s i The channel frequency domain response of the jth receiving antenna port at the m′th subcarrier where the pilot is placed; is the i-th uplink time slot s i The jth zero mean value at the m′th pilot subcarrier, the zero mean value set is 10. The 5G uplink low-power repeated transmission method according to claim 9, characterized in that: By formula Calculate the i-th uplink time slot s i Channel frequency domain response of the jth receiving antenna port at the m′th pilot subcarrier By formula Calculate the i-th uplink time slot s i Channel frequency domain response of the jth receiving antenna port at the mth uplink signal subcarrier

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