Fractional-order digital-analog hybrid fronthaul method and system

Abstract

The present invention provides a fractional-order digital-analog hybrid fronthaul method and system, comprising: a signal processing and transmission step: at the transmitting end, splitting the wireless signal into two parts, performing different-order digital-analog hybrid modulation on the two parts, and then performing frequency division multiplexing to achieve fractional bandwidth expansion; a signal reception and processing step: at the receiving end, demodulating the two different-order digital-analog hybrid optical wireless signals to recover the wireless signal. By adopting fractional-order digital-analog hybrid modulation, the present invention overcomes the problem that conventional digital-analog hybrid modulation can only achieve integer-multiple bandwidth expansion, thereby achieving the effect of improving the flexibility of the fronthaul system.

Description

Technical Field

[0001] The present invention relates to the technical field of digital-analog hybrid fronthaul technology, and in particular to a fractional-order digital-analog hybrid fronthaul method and system. Background Art

[0002] Mobile fronthaul ensures connectivity between the optical core network and the wireless mobile network, transmitting wireless signals between the baseband processing unit and the remote radio unit. To meet the high-capacity and high-fidelity requirements of fronthaul links, signal-to-noise ratio (SNR) and spectral efficiency are key performance indicators for wireless over fiber (ROF) technology. Hybrid digital-analog RLOF technology achieves a good compromise between SNR and spectral efficiency by splitting wireless signals into digital and analog components and multiplexing them for transmission. However, it lacks flexibility, and how to flexibly adjust the bandwidth expansion of wireless signals based on the actual fiber system bandwidth remains a key issue.

[0003] Patent document CN117061005A (Application Number: 202311070264.X) discloses a digital-analog fronthaul system. This method alternates the time between modulated digital and analog symbols. At the receiving end, the impairments estimated from the digital symbols are used to directly compensate for the impairments of the analog signal, thereby improving the ability to compensate for the impairments of the analog signal. However, this patent can only achieve bandwidth expansion by integer multiples and cannot be adjusted according to the actual bandwidth of the optical fiber transmission system. This lacks flexibility and cannot fully solve the above-mentioned technical problems. Summary of the Invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide a fractional-order digital analog hybrid forward transmission method and system.

[0005] The fractional-order digital-analog hybrid forward transmission method provided by the present invention includes:

[0006] Signal processing and transmission steps: At the transmitter, the wireless signal is split into two parts, which are modulated with different orders of mixed digital and analog signals, and then frequency-division multiplexed to achieve fractional bandwidth expansion.

[0007] Signal reception and processing steps: At the receiving end, the two parts of the mixed digital-analog optical wireless signals of different orders are demodulated to restore the wireless signal.

[0008] Preferably, the signal processing and transmitting step includes:

[0009] Step 1: Perform frequency domain carrier aggregation on wireless signals from different channels and normalize them to obtain aggregated wireless sampling point signals.

[0010] Step 2: Split the aggregated wireless sampling point signal into a first part and a second part of the wireless signal;

[0011] Step 3: Perform N1-order and N2-order digital-analog hybrid modulation on the first and second wireless signals, respectively, and perform time division multiplexing on each to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal;

[0012] Step 4: Pulse shaping is performed on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal, the N1-order digital-analog mixed signal is scaled, and then frequency division multiplexing is performed on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal to obtain a fractional-order digital-analog mixed signal;

[0013] Step 5: The fractional-order digital-analog mixed signal is subjected to electro-optical conversion, and then the fractional-order digital-analog mixed optical signal is transmitted through an optical fiber.

[0014] Preferably, the signal receiving and processing steps include:

[0015] Step 6: The fractional-order digital-analog mixed optical signal after optical fiber transmission is converted into an electrical signal by a photodiode, and then the electrical signal is sampled to obtain a fractional-order digital-analog mixed signal with noise at the receiving end;

[0016] Step 7: Normalize and perform frequency division multiplexing on the fractional-order digital-analog mixed signal with noise at the receiving end to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal with noise at the receiving end;

[0017] Step 8: Time-division multiplexing is performed on the N1-order mixed digital-analog signal and the N2-order mixed digital-analog signal with noise at the receiving end, and the first and second wireless signals at the receiving end are obtained by performing N1-order and N2-order mixed digital-analog demodulation.

[0018] Step 9: Recombine the first and second wireless signals of the receiving end to recover the aggregated wireless sampling point signal;

[0019] Step 10: Carrier deaggregation is performed on the aggregated wireless sampling point signals and the signals are allocated to corresponding channels.

[0020] Preferably, the step 2 includes:

[0021] Step 2.1: Select a target bandwidth expansion factor and use R t Indicates that R t is a rational number greater than 2 and a non-integer;

[0022] Step 2.2: Based on the target bandwidth expansion multiple, the ratio of the sequence length of the first and second parts of the wireless signal to the sequence length of the entire aggregated wireless sampling point signal is:

[0023]

[0024] Wherein, p represents the ratio of the sequence length of the first part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation, and q represents the ratio of the sequence length of the second part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation. Indicates rounding a number to an integer less than or equal to itself. Indicates rounding a number to an integer greater than or equal to itself;

[0025] Step 2.3: Based on the calculated ratios p and q of the sequence lengths of the first and second wireless signal parts to the sequence length of the entire aggregated wireless sampling point signal, the aggregated wireless sampling point signal is divided into two parts to obtain the first and second wireless signal parts.

[0026] Preferably, the step 3 includes:

[0027] Step 3.1: Based on the target bandwidth extension multiple, calculate the digital-analog hybrid modulation orders N1 and N2 of the first and second wireless signals. The expressions are as follows:

[0028]

[0029] Step 3.2: Perform N1-order digital-analog hybrid modulation on the first part of the wireless signal, that is, divide the first part of the wireless signal into N1 segments of digital signals and 1 segment of analog signals through N1 rounding operations, and then perform time-division multiplexing on these N1+1 segments of signals to obtain an N1-order digital-analog hybrid signal; perform N2-order digital-analog hybrid modulation on the second part of the wireless signal, that is, divide the second part of the wireless signal into N2 segments of digital signals and 1 segment of analog signals through N2 rounding operations, and then perform time-division multiplexing on these N2+1 segments of signals to obtain an N2-order digital-analog hybrid signal.

[0030] The fractional-order digital-analog hybrid forward transmission system provided by the present invention includes:

[0031] Signal processing and transmission module: At the transmitter, the wireless signal is split into two parts, which are modulated with different orders of mixed digital and analog signals, and then frequency-division multiplexed to achieve fractional bandwidth expansion.

[0032] Signal reception and processing module: At the receiving end, the two parts of the mixed digital-analog optical wireless signals of different orders are demodulated to restore the wireless signal.

[0033] Preferably, the signal processing and transmitting module includes:

[0034] Module M1: Performs frequency domain carrier aggregation on wireless signals from different channels and normalizes them to obtain aggregated wireless sampling point signals.

[0035] Module M2: splits the aggregated wireless sampling point signal into the first part and the second part of the wireless signal;

[0036] Module M3: performs N1-order and N2-order digital-analog mixed modulation on the first and second wireless signals, respectively, and performs time division multiplexing on each of them to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal;

[0037] Module M4: performs pulse shaping on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal, scales the N1-order digital-analog mixed signal, and then frequency-division multiplexes the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal to obtain a fractional-order digital-analog mixed signal;

[0038] Module M5: converts the fractional-order digital-analog mixed signal into an electro-optical signal, and then transmits the fractional-order digital-analog mixed optical signal through an optical fiber.

[0039] Preferably, the signal receiving and processing module includes:

[0040] Module M6: Converts the fractional-order mixed digital-analog optical signal transmitted through the optical fiber into an electrical signal through a photodiode. The electrical signal is then sampled to obtain a noisy fractional-order mixed digital-analog signal at the receiving end.

[0041] Module M7: normalizes and performs frequency division multiplexing on the fractional-order digital-analog mixed signal with noise at the receiving end to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal with noise at the receiving end;

[0042] Module M8: performs time division multiplexing on the N1-order mixed digital-analog signal and the N2-order mixed digital-analog signal with noise at the receiving end, and obtains the first and second wireless signals at the receiving end through N1-order and N2-order mixed digital-analog demodulation.

[0043] Module M9: recombines the first and second wireless signals of the receiving end to recover the aggregated wireless sampling point signal;

[0044] Module M10: de-aggregates the aggregated wireless sampling point signals and assigns them to corresponding channels.

[0045] Preferably, the module M2 includes:

[0046] Module M2.1: Select the bandwidth expansion multiple of a target, using R t Indicates that R t is a rational number greater than 2 and a non-integer;

[0047] Module M2.2: Based on the target bandwidth expansion multiple, the ratio of the sequence length of the first and second parts of the wireless signal to the sequence length of the entire aggregated wireless sampling point signal is:

[0048]

[0049] Wherein, p represents the ratio of the sequence length of the first part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation, and q represents the ratio of the sequence length of the second part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation. Indicates rounding a number to an integer less than or equal to itself. Indicates rounding a number to an integer greater than or equal to itself;

[0050] Module M2.3: Based on the calculated ratios p and q of the sequence lengths of the first and second wireless signal parts to the sequence lengths of the entire aggregated wireless sampling point signal, the aggregated wireless sampling point signal is divided into two parts to obtain the first and second wireless signal parts.

[0051] Preferably, the module M3 includes:

[0052] Module M3.1: Based on the target bandwidth expansion multiple, calculate the digital-analog hybrid modulation orders N1 and N2 of the first and second wireless signals, as shown in the following expressions:

[0053]

[0054] Module M3.2: Perform N1-order mixed digital-analog modulation on the first part of the wireless signal. That is, the first part of the wireless signal is divided into N1 digital signal segments and 1 analog signal segment through N1 rounding operations. The N1+1 signal segments are then time-division multiplexed to obtain an N1-order mixed digital-analog signal. Perform N2-order mixed digital-analog modulation on the second part of the wireless signal. That is, the second part of the wireless signal is divided into N2 digital signal segments and 1 analog signal segment through N2 rounding operations. The N2+1 signal segments are then time-division multiplexed to obtain an N2-order mixed digital-analog signal.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] (1) By adopting fractional-order digital-analog hybrid modulation, the present invention solves the problem that conventional digital-analog hybrid modulation can only achieve integer-multiple bandwidth expansion, thereby improving the flexibility of the fronthaul system.

[0057] (2) The present invention solves the problem of low efficiency of signal-to-noise ratio as bandwidth increases by optimizing the power of two parts of different-order digital-analog mixed signals, and achieves an effect of approximately linear signal-to-noise ratio growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0059] Figure 1 This is the flow chart of the transmitter of the fractional-order digital-analog hybrid fronthaul system;

[0060] Figure 2 This is the flow chart of the receiving end of the fractional-order digital analog hybrid fronthaul system;

[0061] Figure 3 It is the spectrum diagram of fractional-order digital-analog mixed signal. DETAILED DESCRIPTION

[0062] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0063] Example 1

[0064] The present invention provides a fractional-order digital-analog hybrid forward transmission method, comprising:

[0065] Signal processing and transmission steps: At the transmitter, the wireless signal is split into two parts, which are modulated with different orders of mixed digital and analog signals, and then frequency-division multiplexed to achieve fractional bandwidth expansion.

[0066] Signal reception and processing steps: At the receiving end, the two parts of the mixed digital-analog optical wireless signals of different orders are demodulated to restore the wireless signal.

[0067] like Figure 1 , the signal processing and transmitting steps include:

[0068] Step 1: Perform frequency domain carrier aggregation on wireless signals from different channels and normalize them to obtain aggregated wireless sampling point signals.

[0069] Step 2: Split the aggregated wireless sampling point signal into a first part and a second part of the wireless signal;

[0070] Step 3: Perform N1-order and N2-order digital-analog hybrid modulation on the first and second wireless signals, respectively, and perform time division multiplexing on each to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal;

[0071] Step 4: Pulse shaping is performed on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal, the N1-order digital-analog mixed signal is scaled, and then frequency division multiplexing is performed on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal to obtain a fractional-order digital-analog mixed signal;

[0072] Step 5: The fractional-order digital-analog mixed signal is subjected to electro-optical conversion, and then the fractional-order digital-analog mixed optical signal is transmitted through an optical fiber.

[0073] like Figure 2 , the signal receiving and processing steps include:

[0074] Step 6: The fractional-order digital-analog mixed optical signal after optical fiber transmission is converted into an electrical signal by a photodiode, and then the electrical signal is sampled to obtain a fractional-order digital-analog mixed signal with noise at the receiving end;

[0075] Step 7: Normalize and perform frequency division multiplexing on the fractional-order digital-analog mixed signal with noise at the receiving end to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal with noise at the receiving end;

[0076] Step 8: Time-division multiplexing is performed on the N1-order mixed digital-analog signal and the N2-order mixed digital-analog signal with noise at the receiving end, and the first and second wireless signals at the receiving end are obtained by performing N1-order and N2-order mixed digital-analog demodulation.

[0077] Step 9: Recombine the first and second wireless signals of the receiving end to recover the aggregated wireless sampling point signal;

[0078] Step 10: Carrier deaggregation is performed on the aggregated wireless sampling point signals and the signals are allocated to corresponding channels.

[0079] The step 2 comprises the following steps:

[0080] Step 2.1: Select a target bandwidth expansion factor and use R t Indicates that R t is a rational number greater than 2 and a non-integer;

[0081] Step 2.2: Based on the target bandwidth expansion multiple, the ratio of the sequence length of the first and second parts of the wireless signal to the sequence length of the entire aggregated wireless sampling point signal is:

[0082]

[0083] Wherein, p represents the ratio of the sequence length of the first part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation, and q represents the ratio of the sequence length of the second part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation. Indicates rounding a number to an integer less than or equal to itself. Indicates rounding a number to an integer greater than or equal to itself;

[0084] Step 2.3: Based on the calculated ratios p and q of the sequence lengths of the first and second wireless signal parts to the sequence length of the entire aggregated wireless sampling point signal, the aggregated wireless sampling point signal is divided into two parts to obtain the first and second wireless signal parts.

[0085] The step 3 comprises the following steps:

[0086] Step 3.1: Based on the target bandwidth extension multiple, calculate the digital-analog hybrid modulation orders N1 and N2 of the first and second wireless signals. The expressions are as follows:

[0087]

[0088] Step 3.2: Perform N1-order digital-analog hybrid modulation on the first part of the wireless signal, that is, divide the first part of the wireless signal into N1 segments of digital signals and 1 segment of analog signals through N1 rounding operations, and then perform time-division multiplexing on these N1+1 segments of signals to obtain an N1-order digital-analog hybrid signal; perform N2-order digital-analog hybrid modulation on the second part of the wireless signal, that is, divide the second part of the wireless signal into N2 segments of digital signals and 1 segment of analog signals through N2 rounding operations, and then perform time-division multiplexing on these N2+1 segments of signals to obtain an N2-order digital-analog hybrid signal.

[0089] Figure 3 The spectrum of the fractional-order digital-analog mixed signal after frequency division multiplexing is presented. The power of the two subcarriers is optimized. The first subcarrier is the first-order digital-analog mixed signal, and the second subcarrier is the second-order digital-analog mixed signal.

[0090] Example 2

[0091] The present invention also provides a fractional-order digital-analog hybrid fronthaul system, which can be implemented by executing the process steps of the fractional-order digital-analog hybrid fronthaul method. That is, those skilled in the art can understand the fractional-order digital-analog hybrid fronthaul method as a preferred implementation of the fractional-order digital-analog hybrid fronthaul system.

[0092] The fractional-order digital-analog hybrid fronthaul system provided by the present invention includes: a signal processing and transmission module: at the transmitting end, the wireless signal is split into two parts, the two parts are modulated with digital-analog hybrid of different orders, and then frequency division multiplexing is performed to achieve fractional bandwidth expansion; a signal receiving and processing module: at the receiving end, the two parts of the digital-analog hybrid optical wireless signals of different orders are demodulated to restore the wireless signal.

[0093] The signal processing and transmission module includes: module M1: performing frequency domain carrier aggregation on wireless signals from different channels in the frequency domain and normalizing them to obtain aggregated wireless sampling point signals; module M2: performing signal splitting on the aggregated wireless sampling point signals to divide them into a first part and a second part of wireless signals; module M3: performing N1-order and N2-order digital-analog mixed modulation on the first part and the second part of the wireless signals respectively, and performing time division multiplexing on each of them to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal; module M4: performing pulse shaping on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal, scaling the N1-order digital-analog mixed signal, and then performing frequency division multiplexing on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal to obtain a fractional-order digital-analog mixed signal; module M5: performing electro-optical conversion on the fractional-order digital-analog mixed signal, and then transmitting the fractional-order digital-analog mixed optical signal through optical fiber.

[0094] The signal receiving and processing module includes: module M6: performing photoelectric conversion on the fractional-order digital-analog mixed optical signal after optical fiber transmission through a photodiode to obtain an electrical signal, and then sampling the electrical signal to obtain a noisy fractional-order digital-analog mixed signal at the receiving end; module M7: normalizing and frequency-demultiplexing the noisy fractional-order digital-analog mixed signal at the receiving end to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal at the receiving end; module M8: performing time-demultiplexing on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal at the receiving end, and performing N1-order and N2-order digital-analog mixed demodulation to obtain the first and second parts of the wireless signals at the receiving end; module M9: performing signal recombination on the first and second parts of the wireless signals at the receiving end to recover the aggregated wireless sampling point signals; module M10: performing carrier deaggregation on the aggregated wireless sampling point signals and assigning them to corresponding channels.

[0095] The module M2 includes: Module M2.1: Select a bandwidth expansion multiple of a certain target, use R t Indicates that R t is a rational number greater than 2 and a non-integer; Module M2.2: Based on the target bandwidth expansion multiple, the ratio of the sequence length of the first and second parts of the wireless signal to the sequence length of the entire aggregated wireless sampling point signal is: Wherein, p represents the ratio of the sequence length of the first part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation, and q represents the ratio of the sequence length of the second part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation. Indicates rounding a number to an integer less than or equal to itself. Indicates rounding a number to an integer greater than or equal to itself. Module M2.3: Based on the calculated ratios p and q of the sequence lengths of the first and second parts of the wireless signal to the sequence lengths of the entire aggregated wireless sampling point signal, the aggregated wireless sampling point signal is divided into two parts to obtain the first and second parts of the wireless signal.

[0096] The module M3 includes: module M3.1: according to the target bandwidth extension multiple, the digital-analog hybrid modulation orders N1 and N2 of the first and second wireless signals are calculated, and the expressions are as follows: Module M3.2: Perform N1-order mixed digital-analog modulation on the first part of the wireless signal. That is, the first part of the wireless signal is divided into N1 digital signal segments and 1 analog signal segment through N1 rounding operations. The N1+1 signal segments are then time-division multiplexed to obtain an N1-order mixed digital-analog signal. Perform N2-order mixed digital-analog modulation on the second part of the wireless signal. That is, the second part of the wireless signal is divided into N2 digital signal segments and 1 analog signal segment through N2 rounding operations. The N2+1 signal segments are then time-division multiplexed to obtain an N2-order mixed digital-analog signal.

[0097] Those skilled in the art will appreciate that, in addition to implementing the system, device, and various modules provided by the present invention in purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, and the like by logically programming the method steps. Therefore, the system, device, and various modules provided by the present invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; the modules for implementing various functions can also be considered both software programs for implementing the method and structures within the hardware component.

[0098] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A fractional-order digital analog hybrid forward transmission method, characterized in that: include: Signal processing and transmission steps: At the transmitter, the wireless signal is split into two parts, which are modulated with different orders of mixed digital and analog signals, and then frequency-division multiplexed to achieve fractional bandwidth expansion. Signal reception and processing steps: At the receiving end, the two parts of the mixed digital-analog optical wireless signals of different orders are demodulated to recover the wireless signal; The signal processing and transmitting steps include: Step 1: Perform frequency domain carrier aggregation on wireless signals from different channels and normalize them to obtain aggregated wireless sampling point signals. Step 2: Split the aggregated wireless sampling point signal into a first part and a second part of the wireless signal; Step 3: Perform N1-order and N2-order digital-analog hybrid modulation on the first and second wireless signals, respectively, and perform time division multiplexing on each to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal; Step 4: Pulse shaping is performed on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal, the N1-order digital-analog mixed signal is scaled, and then frequency division multiplexing is performed on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal to obtain a fractional-order digital-analog mixed signal; Step 5: The fractional-order digital-analog mixed signal is subjected to electro-optical conversion, and then the fractional-order digital-analog mixed optical signal is transmitted through an optical fiber; The signal receiving and processing steps include: Step 6: The fractional-order digital-analog mixed optical signal after optical fiber transmission is converted into an electrical signal by a photodiode, and then the electrical signal is sampled to obtain a fractional-order digital-analog mixed signal with noise at the receiving end; Step 7: Normalize and perform frequency division multiplexing on the fractional-order digital-analog mixed signal with noise at the receiving end to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal with noise at the receiving end; Step 8: Time-division multiplexing is performed on the N1-order mixed digital-analog signal and the N2-order mixed digital-analog signal with noise at the receiving end, and the first and second wireless signals at the receiving end are obtained by performing N1-order and N2-order mixed digital-analog demodulation. Step 9: Recombine the first and second wireless signals of the receiving end to recover the aggregated wireless sampling point signal; Step 10: Carrier deaggregation is performed on the aggregated wireless sampling point signals and the signals are allocated to corresponding channels; The step 2 includes: Step 2.1: Select a target bandwidth expansion factor and use R t Indicates that R t is a rational number greater than 2 and a non-integer; Step 2.2: Based on the target bandwidth expansion multiple, the ratio of the sequence length of the first and second parts of the wireless signal to the sequence length of the entire aggregated wireless sampling point signal is: Wherein, p represents the ratio of the sequence length of the first part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation, and q represents the ratio of the sequence length of the second part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation. Indicates rounding a number to an integer less than or equal to itself. Indicates rounding a number to an integer greater than or equal to itself; Step 2.3: Based on the calculated ratios p and q of the sequence lengths of the first and second wireless signal parts to the sequence length of the entire aggregated wireless sampling point signal, the aggregated wireless sampling point signal is divided into two parts to obtain the first and second wireless signal parts.

2. The fractional-order digital-analog hybrid forward transmission method according to claim 1, characterized in that: The step 3 comprises: Step 3.1: Based on the target bandwidth extension factor, calculate the digital-analog hybrid modulation orders N1 and N2 of the first and second wireless signals. The expressions are as follows: Step 3.2: Perform N1-order digital-analog hybrid modulation on the first part of the wireless signal, that is, divide the first part of the wireless signal into N1 segments of digital signals and 1 segment of analog signals through N1 rounding operations, and then perform time-division multiplexing on these N1+1 segments of signals to obtain an N1-order digital-analog hybrid signal; perform N2-order digital-analog hybrid modulation on the second part of the wireless signal, that is, divide the second part of the wireless signal into N2 segments of digital signals and 1 segment of analog signals through N2 rounding operations, and then perform time-division multiplexing on these N2+1 segments of signals to obtain an N2-order digital-analog hybrid signal.

3. A fractional-order digital analog hybrid fronthaul system, characterized in that: include: Signal processing and transmission module: At the transmitter, the wireless signal is split into two parts, which are modulated with different orders of mixed digital and analog signals, and then frequency-division multiplexed to achieve fractional bandwidth expansion. Signal reception and processing module: At the receiving end, it demodulates the two parts of the mixed digital-analog optical wireless signals of different orders and recovers the wireless signal; The signal processing and transmission module includes: Module M1: Performs frequency domain carrier aggregation on wireless signals from different channels and normalizes them to obtain aggregated wireless sampling point signals. Module M2: splits the aggregated wireless sampling point signal into the first part and the second part of the wireless signal; Module M3: performs N1-order and N2-order digital-analog mixed modulation on the first and second wireless signals, respectively, and performs time division multiplexing on each of them to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal; Module M4: performs pulse shaping on the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal, scales the N1-order digital-analog mixed signal, and then frequency-division multiplexes the N1-order digital-analog mixed signal and the N2-order digital-analog mixed signal to obtain a fractional-order digital-analog mixed signal; Module M5: converts the fractional-order digital-analog mixed signal into optical signals and then transmits the fractional-order digital-analog mixed optical signal through optical fiber. The signal receiving and processing module includes: Module M6: Converts the fractional-order mixed digital-analog optical signal transmitted through the optical fiber into an electrical signal through a photodiode. The electrical signal is then sampled to obtain a noisy fractional-order mixed digital-analog signal at the receiving end. Module M7: normalizes and performs frequency division multiplexing on the fractional-order digital-analog mixed signal with noise at the receiving end to obtain an N1-order digital-analog mixed signal and an N2-order digital-analog mixed signal with noise at the receiving end; Module M8: performs time division multiplexing on the N1-order mixed digital-analog signal and the N2-order mixed digital-analog signal with noise at the receiving end, and obtains the first and second wireless signals at the receiving end through N1-order and N2-order mixed digital-analog demodulation. Module M9: recombines the first and second wireless signals of the receiving end to recover the aggregated wireless sampling point signal; Module M10: deaggregates the aggregated wireless sampling point signals and assigns them to the corresponding channels; The module M2 includes: Module M2.1: Select the bandwidth expansion multiple of a target, using R t Indicates that R t is a rational number greater than 2 and a non-integer; Module M2.2: Based on the target bandwidth expansion multiple, the ratio of the sequence length of the first and second parts of the wireless signal to the sequence length of the entire aggregated wireless sampling point signal is: Wherein, p represents the ratio of the sequence length of the first part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation, and q represents the ratio of the sequence length of the second part of the wireless signal to the sequence length of the entire wireless sampling point signal after aggregation. Indicates rounding a number to an integer less than or equal to itself. Indicates rounding a number to an integer greater than or equal to itself; Module M2.3: Based on the calculated ratios p and q of the sequence lengths of the first and second wireless signal parts to the sequence lengths of the entire aggregated wireless sampling point signal, the aggregated wireless sampling point signal is divided into two parts to obtain the first and second wireless signal parts.

4. The fractional-order digital-analog hybrid fronthaul system according to claim 3, characterized in that: The module M3 includes: Module M3.1: Based on the target bandwidth expansion multiple, calculate the digital-analog hybrid modulation orders N1 and N2 of the first and second wireless signals, as shown in the following expressions: Module M3.2: Perform N1-order mixed digital-analog modulation on the first part of the wireless signal. That is, the first part of the wireless signal is divided into N1 digital signal segments and 1 analog signal segment through N1 rounding operations. The N1+1 signal segments are then time-division multiplexed to obtain an N1-order mixed digital-analog signal. Perform N2-order mixed digital-analog modulation on the second part of the wireless signal. That is, the second part of the wireless signal is divided into N2 digital signal segments and 1 analog signal segment through N2 rounding operations. The N2+1 signal segments are then time-division multiplexed to obtain an N2-order mixed digital-analog signal.

Images