CN117061005A - Digital analog forwarding system - Google Patents
Digital analog forwarding system Download PDFInfo
- Publication number
- CN117061005A CN117061005A CN202311070264.XA CN202311070264A CN117061005A CN 117061005 A CN117061005 A CN 117061005A CN 202311070264 A CN202311070264 A CN 202311070264A CN 117061005 A CN117061005 A CN 117061005A
- Authority
- CN
- China
- Prior art keywords
- analog
- digital
- symbols
- symbol
- modulated
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
- 238000013139 quantization Methods 0.000 claims abstract description 15
- 238000000034 method Methods 0.000 claims description 30
- 230000008569 process Effects 0.000 claims description 20
- 230000005540 biological transmission Effects 0.000 claims description 13
- 230000001427 coherent effect Effects 0.000 claims description 13
- 238000000926 separation method Methods 0.000 claims description 7
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000006735 deficit Effects 0.000 description 11
- 238000012545 processing Methods 0.000 description 9
- 238000004891 communication Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 230000010287 polarization Effects 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000001514 detection method Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 238000010295 mobile communication Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2575—Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/5161—Combination of different modulation schemes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/616—Details of the electronic signal processing in coherent optical receivers
- H04B10/6162—Compensation of polarization related effects, e.g., PMD, PDL
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/616—Details of the electronic signal processing in coherent optical receivers
- H04B10/6164—Estimation or correction of the frequency offset between the received optical signal and the optical local oscillator
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/616—Details of the electronic signal processing in coherent optical receivers
- H04B10/6165—Estimation of the phase of the received optical signal, phase error estimation or phase error correction
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Electromagnetism (AREA)
- Optics & Photonics (AREA)
- Error Detection And Correction (AREA)
Abstract
The invention discloses a digital analog forwarding system, which comprises: a DSP transmitting end, a DSP receiving end and a time interleaving digital-analog wireless forwarding architecture; the DSP transmitting end carries out quantization modulation on a wireless signal to be modulated to obtain a modulated digital symbol and an analog symbol, and carries out time domain interleaving through a time interleaving digital-analog wireless forwarding framework to obtain an interleaved digital symbol and an interleaved analog symbol, wherein the digital symbol and the analog symbol are alternately placed in the time interleaving digital-analog wireless forwarding framework; and the DSP receiving end judges and recovers the interleaved digital symbols and analog symbols to obtain wireless signals. Because the invention alternately places the digital symbols and the analog symbols for time domain interleaving through the time interleaving digital-analog wireless forwarding architecture, the damage estimated from the digital symbols can be directly used for compensating the damage of the analog signals in the DSP receiving end to obtain the wireless signals, thereby realizing the dynamic damage compensation of the analog symbols.
Description
Technical Field
The invention relates to the technical field of communication, in particular to a digital-analog forwarding system.
Background
With the rapid development of the fifth generation (5G) mobile communication, for the mobile forwarding network, radio signals may be transmitted from a baseband unit (BBU) to a Remote Radio Unit (RRU) using Radio over Fiber (RoF), so as to support multiple mobile users. Whereas the conventional forwarding scheme includes: analogRoF(a-RoF)schemes,digitalRoFbasedonphasemodulation(PM)(PM-a-RoF)schemes,andmixeddigitalAnalogRoFbasedondsp(da-RoF)schemes,butimprovesignaltonoiseratioattheexpenseofspectralefficiencyandcapacity.
In order to increase the capacity of the RoF system, the modulation dimension of the DA-RoF is generally increased by using a bi-polarized quadrature amplitude modulation coherent detection system. Although the modulation dimension of the DA-RoF is improved, there are still dynamic impairments such as phase noise and dynamic polarization rotation.
The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present invention and is not intended to represent an admission that the foregoing is prior art.
Disclosure of Invention
The invention mainly aims to provide a digital analog forward transmission system, which aims to solve the technical problems that the existing double-bias quadrature amplitude modulation coherent detection system improves the modulation dimension of DA-RoF, but the dynamic damage such as phase noise, dynamic polarization rotation and the like still exists.
To achieve the above object, the present invention provides a digital-to-analog forwarding system including: a DSP transmitting end, a DSP receiving end and a time interleaving digital-analog wireless forwarding architecture;
the DSP transmitting end is used for carrying out quantization modulation on the wireless signal to be modulated when the wireless signal to be modulated is received, so as to obtain a modulated digital symbol and an analog symbol;
the time-interleaved digital-to-analog wireless front-end architecture is used for performing time-domain interleaving on the modulated digital symbols and analog symbols to obtain interleaved digital symbols and analog symbols, wherein the digital symbols and the analog symbols are alternately placed in the time-interleaved digital-to-analog wireless front-end architecture;
and the DSP receiving end is used for judging and recovering the digital symbols and the analog symbols after interleaving to obtain wireless signals.
Optionally, the time-interleaved digital-to-analog wireless preamble architecture includes alternating a plurality of digital symbol combinations and a plurality of analog symbol combinations.
Optionally, when the time-interleaved digital-to-analog wireless forwarding architecture is a higher-order architecture, the higher-order digital symbols and the higher-order analog symbols generated by the separation of the analog symbols of the previous order are alternately placed.
Optionally, the DSP transmitting end is further configured to perform quantization operation on a wireless signal to be modulated to obtain a modulated digital symbol, where the process is:
S Tx ＝Q ro (S Tx )；
wherein Q is ro To quantize a quantization factor using a rounding principle, S Tx For the wireless signal to be modulated, D Tx Is a modulated digital symbol.
Optionally, the DSP transmitting end is further configured to perform a difference between the to-be-modulated wireless signal and the modulated digital symbol to obtain a modulated analog symbol, where the process is:
A Tx ＝S Tx -D Tx ；
wherein S is Tx For the wireless signal to be modulated, D Tx For modulated digital symbols, A Tx Is a modulated analog symbol.
Optionally, the DSP receiving end is further configured to perform symbol decision on the interleaved digital symbol to obtain a decided digital signal;
the DSP receiving end is also used for carrying out damage compensation on the interleaved analog symbols to obtain compensated analog signals.
Optionally, the DSP receiving end is further configured to add the determined digital signal and the compensated analog signal to obtain a recovered wireless signal, where the process is:
S Rx ＝A Rx +D Rx ；
wherein D is Rx A as the digital signal after the judgment Rx For compensated analog signals, S Rx Is the recovered wireless signal.
Optionally, the time-interleaved digital-analog wireless forwarding architecture is further configured to perform high-order separation on an analog symbol of a previous order to obtain a high-order digital symbol and a high-order analog symbol, and perform time-domain interleaving on the high-order digital symbol and the high-order analog symbol to obtain an interleaved digital symbol and an interleaved analog symbol.
Optionally, the DSP receiving end is further configured to add the digital symbol of the high order and the analog symbol of the high order to obtain a recovered wireless signal, where the process is:
S Rx_N ＝A Rx +D Rx_1 +D Rx_2 +…+D Rx_N ；
wherein D is Rx_1 D is the digital signal after the first order judgment Rx_2 Is a digital signal after the second order judgment, D Rx_N Is a digital signal after Nth order judgment, A Rx For compensated analog signals, S Rx_N Is the recovered wireless signal.
Optionally, the DSP receiving end and the DSP transmitting end are implemented based on a coherent receiver, which includes a PIN detector and a photo detector with transimpedance amplification.
The invention provides a digital-analog forwarding system, which comprises: a DSP transmitting end, a DSP receiving end and a time interleaving digital-analog wireless forwarding architecture; the DSP transmitting end is used for carrying out quantization modulation on the wireless signal to be modulated when the wireless signal to be modulated is received, so as to obtain a modulated digital symbol and an analog symbol; the time-interleaved digital-to-analog wireless front-end architecture is used for performing time-domain interleaving on the modulated digital symbols and analog symbols to obtain interleaved digital symbols and analog symbols, wherein the digital symbols and the analog symbols are alternately placed in the time-interleaved digital-to-analog wireless front-end architecture; and the DSP receiving end is used for judging and recovering the digital symbols and the analog symbols after interleaving to obtain wireless signals. The invention alternately places the digital symbols and the analog symbols for time domain interleaving through the time interleaving digital-analog wireless forwarding architecture, so that the estimated damage from the digital symbols can be directly used for damage compensation of the analog signals in the DSP receiving end to obtain wireless signals, and the dynamic damage compensation of the analog symbols is realized.
Drawings
FIG. 1 is a block diagram of a first embodiment of a digital-to-analog forwarding system of the present invention;
FIG. 2 is a schematic diagram of a digital-to-analog forwarding system implemented based on a coherent communication system according to a first embodiment of the present invention;
FIG. 3 is a schematic diagram of a modified first-order time-interleaved digital-to-analog wireless preamble architecture of a digital-to-analog preamble system according to a second embodiment of the present invention;
fig. 4 is a schematic diagram of a modified high-order time-interleaved digital-to-analog wireless preamble architecture of a digital-to-analog preamble system according to a second embodiment of the present invention.
The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Detailed Description
It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
An embodiment of the present invention provides a digital-to-analog forwarding system, and referring to fig. 1, fig. 1 is a block diagram of a first embodiment of the digital-to-analog forwarding system according to the present invention.
With the rapid development of the fifth generation (5G) mobile communication, for the mobile forwarding network, radio signals may be transmitted from a baseband unit (BBU) to a Remote Radio Unit (RRU) using Radio over Fiber (RoF), so as to support multiple mobile users. The traditional forwarding schemes include the following steps:
1. analog RoF (Analog-RoF, a-RoF), however Analog signals are susceptible to inter-symbol interference and nonlinear distortion, which require compensation in Digital Signal Processing (DSP). Nonlinear compensation using a nonlinear equalizer has been proposed. However, the signal-to-noise ratio of the non-linear equalizer based a-RoF scheme is limited to about 22-25 db. It can only support 64-QAM at most, below the 32 dB SNR requirement required to support 1024-QAM specified in the latest 3GPP standards.
2. phasemodulation(PM)baseda-ROF(PM-a-ROF)schemesimprovethesignaltonoiseratioattheexpenseofspectralefficiencyby6dbforeveryhalvingofspectralefficiency.
3. theDSP-basedmixeddigital-analogRoF(DA-RoF)schemeachievesasignal-to-noiseratiogainofover10db,exceedingthe6dbgainofthePM-a-RoFscheme,attheexpenseofhalfspectralefficiency.
But the above approach improves the signal-to-noise ratio at the expense of spectral efficiency and capacity. To further increase the capacity of RoF systems, the modulation dimension of DA-RoF is typically increased by a factor of four using a bi-polarized quadrature amplitude modulation coherent detection system. In coherent communication systems, however, dynamic impairments such as phase noise and dynamic polarization rotation still exist. To alleviate this problem, there are two schemes, one is pilot-based, that can estimate dynamic channel impairments. However, the pilot increases the PAPR of the transmitted signal, making it more susceptible to channel noise. The second is to use the homodyne coherence of homology, can dispel the influence of the phase noise perfectly under the precondition of phase matching, this scheme needs extra polarization controller to control the local oscillator light transmitted jointly, in order to carry on the coherent reception, will increase the hardware complexity of the system.
Therefore, the invention provides a digital analog forwarding system, which can track and compensate dynamic damage on the premise of not increasing hardware complexity and not using pilot frequency, thereby realizing a RoF system with ultra-large capacity and meeting the forwarding demands of the later 5G and 6G times.
In this embodiment, the digital-analog forwarding system includes: a DSP transmitting end, a DSP receiving end and a time interleaving digital-analog wireless forwarding architecture;
the DSP transmitting end is used for carrying out quantization modulation on the wireless signal to be modulated when the wireless signal to be modulated is received, so as to obtain a modulated digital symbol and an analog symbol;
the time-interleaved digital-to-analog wireless front-end architecture is used for performing time-domain interleaving on the modulated digital symbols and analog symbols to obtain interleaved digital symbols and analog symbols, wherein the digital symbols and the analog symbols are alternately placed in the time-interleaved digital-to-analog wireless front-end architecture;
and the DSP receiving end is used for judging and recovering the digital symbols and the analog symbols after interleaving to obtain wireless signals.
The DSP transmitting end refers to a transmitting part of the digital signal processing (Digital Signal Processing) system. In wireless communications, the main function of the DSP transmitting end is to convert digital information into analog signals suitable for wireless transmission and to perform the necessary modulation, coding and filtering operations.
It is understood that the DSP receiving end refers to the receiving portion of the digital signal processing system. In wireless communication, a main function of a DSP receiving end is to receive and process an analog signal transmitted from a wireless channel, convert it into a digital signal, and perform subsequent processing and decoding.
It should be understood that the time-interleaved digital-to-analog wireless preamble architecture is a new time-interleaved (time-interleaved) DA-RoF (TI-DA-RoF) architecture proposed in this embodiment. On the basis of realizing a high-capacity forward system, compared with the prior art, the method can estimate and compensate the dynamic damage without pilot frequency assistance or an autocorrelation framework. In the time-interleaved digital-analog wireless forwarding architecture, digital symbols and analog symbols are alternately placed, and the estimated damage from the digital symbols can be directly used for compensating the damage of analog signals through a DSP receiving end, so that the dynamic damage compensation of an analog part is realized.
It should be noted that, the wireless signal to be modulated refers to an original signal before digital modulation, and the original signal may be digital data, a voice signal, or other types of information. Digital symbols are the different signal states or waveforms used in modulation to represent digital information. Analog symbols are discrete representations of symbols used in modulation to transmit an analog signal, since in analog communications the signal is continuously changing, whereas for processing and transmission in digital systems, the signal needs to be discretized into a series of discrete analog symbols.
In a specific implementation, when the DSP transmitting end receives a wireless signal to be modulated, the wireless signal to be modulated is quantized and modulated to obtain a modulated digital symbol and a modulated analog symbol; and then, the modulated digital symbols and the modulated analog symbols are alternately placed through the time interleaving digital-analog wireless forwarding architecture, and are subjected to time domain interleaving, so that the damage of the system can be estimated through the modulated digital symbols and applied to the adjacent modulated analog symbols, and the damage compensation of the analog part is performed. Finally, the digital symbol and the analog symbol after interleaving are judged and recovered through the DSP receiving end, and a wireless signal is obtained. The analog part is directly compensated after the damage is estimated based on the digital part, so that the blind equalization of the link damage can be realized, the dynamic damage can be tracked to a certain extent, the practicability of the link system is improved, and the high-fidelity transmission of the wireless signal is realized.
For ease of understanding, the process is illustrated as being implemented on a hardware basis, but the present solution is not limited thereto. Referring to fig. 2, fig. 2 is a schematic diagram of a digital-to-analog forwarding system implemented based on a coherent communication system according to a first embodiment of the digital-to-analog forwarding system of the present invention. As shown in fig. 2, the lower part is a hardware base including: a double-bias IQ modulator, a coherent receiver, a laser and a local oscillator laser; the signal is subjected to analog-to-digital conversion and digital-to-analog conversion in the transmission process by the double-offset IQ modulator. The first-order time interleaving digital-to-analog wireless forwarding architecture is selected to perform TI-DA-RoF modulation on the wireless signal to be transmitted. The method comprises the steps of receiving signals by using a coherent receiver, compensating the damage by polarization rotation, frequency offset estimation and carrier phase recovery through a transmitting end DSP and a receiving end DSP, and then recovering wireless signals through demodulation of TI-DA-RoF. The specific modulation process and demodulation process in the forward link are: modulating by an N rho-QAM quantizer to obtain an alpha-times amplified digital signal and a beta-times amplified analog signal, alternately placing the modulated digital symbols and the modulated analog symbols by the time interleaving digital-analog wireless forwarding architecture, and performing time domain interleaving on the modulated digital symbols, so that the damage of a system can be estimated by the modulated digital symbols and applied to adjacent modulated analog symbols, and damage compensation of an analog part is performed. And finally, carrying out symbol judgment on the digital symbol, and then carrying out 1/alpha and 1/beta times reduction to obtain a wireless signal.
In the proposed time-interleaved digital-to-analog wireless forwarding architecture, high-fidelity transmission of wireless signals can be realized, and in a channel with an actual 21 dB signal-to-noise ratio, wireless signal transmission equivalent to more than 32 dB signal-to-noise ratio can be realized, and the transmission requirement of 1024-QAM can be met. Compared with the existing pilot frequency auxiliary scheme and homodyne self-coherent scheme, the method can realize carrier recovery based on blind phase search of digital signals. Compared with a pilot auxiliary scheme, the scheme can simplify the DSP flow of the transmitting end and avoid the peak-to-average power ratio improvement caused by pilot insertion, and the quantization noise in the DAC conversion process can be increased by the larger peak-to-average power ratio. Compared with the homodyne self-coherence scheme, the scheme does not need an extra optical fiber link (used for transmitting the homologous local oscillation LO) and an extra polarization controller (used for controlling the polarization direction of the LO), so that the hardware complexity and the power consumption are lower.
In the embodiment, when the DSP transmitting end receives a wireless signal to be modulated, the wireless signal to be modulated is subjected to quantization modulation to obtain a modulated digital symbol and a modulated analog symbol; and then, the modulated digital symbols and the modulated analog symbols are alternately placed through the time interleaving digital-analog wireless forwarding architecture, and are subjected to time domain interleaving, so that the damage of the system can be estimated through the modulated digital symbols and applied to the adjacent modulated analog symbols, and the damage compensation of the analog part is performed. Finally, the digital symbol and the analog symbol after interleaving are judged and recovered through the DSP receiving end, and a wireless signal is obtained. Because the invention alternately places the digital symbols and the analog symbols for time domain interleaving through the time interleaving digital-analog wireless forwarding architecture, the analog portion is directly compensated after the damage is estimated based on the digital portion, the link damage can be subjected to blind equalization, and the dynamic damage compensation of the analog symbols is realized.
Based on the above-described first embodiment, a second embodiment of the digital-analog fronthaul system of the present invention is presented.
In this embodiment, the DSP transmitting end is further configured to perform quantization operation on a wireless signal to be modulated to obtain a modulated digital symbol, where the process is:
D Tx ＝Q ro (S Tx )；
wherein Q is ro To quantize a quantization factor using a rounding principle, S Tx For the wireless signal to be modulated, D Tx Is a modulated digital symbol.
In a specific implementation, in a DSP transmitting end, a wireless signal S to be modulated is transmitted Tx Quantization operation is carried out to obtain a digital symbol D which is amplified accurately Tx 。
Further, in this embodiment, the DSP transmitting end is further configured to perform a difference between the to-be-modulated wireless signal and the modulated digital symbol to obtain a modulated analog symbol, where the process is:
A Tx ＝S Tx -D Tx ；
wherein S is Tx For the wireless signal to be modulated, D Tx For modulated digital symbols, A Tx Is a modulated analog symbol.
In a specific implementation, quantization noise is obtained by differencing the wireless signal to be modulated and the quantized digital symbol, namely the modulated accurate analog symbol A is obtained Tx 。
Further, in this embodiment, the DSP receiving end is further configured to perform symbol decision on the interleaved digital symbol to obtain a decided digital signal;
the DSP receiving end is also used for carrying out damage compensation on the interleaved analog symbols to obtain compensated analog signals.
Further, in this embodiment, the DSP receiving end is further configured to add the determined digital signal and the compensated analog signal to obtain a recovered wireless signal, where the process is:
S Rx ＝A Rx +D Rx ；
wherein D is Rx A as the digital signal after the judgment Rx For compensated analog signals, S Rx Is the recovered wireless signal.
In a specific implementation, in a DSP receiving end, the digital signal D after decision is processed Rx And an analog signal A after damage compensation Rx And adding, and recovering the wireless signals.
Further, considering the architecture of multiple symbol combinations, the present embodiment proposes a modified time-interleaved digital-to-analog wireless preamble architecture with N digital and N analog symbol time-domain interleaving combinations. Fig. 3 is a schematic diagram of a digital symbol and analog symbol arrangement of a modified first-order time-interleaved digital-to-analog wireless forwarding architecture in a second embodiment of the digital-to-analog forwarding system according to the present invention. The time-interleaved digital-to-analog wireless preamble architecture described in this embodiment includes alternating a plurality of digital symbol combinations and a plurality of analog symbol combinations.
In the field of communications, OFDM Symbol (and CP) is a time unit for transmitting data in OFDM multi-carrier modulation technology, and is composed of a plurality of subcarriers, and efficient spectrum utilization and interference rejection are achieved by orthogonal modulation.
Further, considering the high-order architecture, the present embodiment proposes a modified high-order time-interleaved digital-to-analog wireless preamble architecture, which performs time-domain interleaving by dividing the analog part generated in the first order into digital and analog symbols again; the analog part of the second order generation is then separated again into digital and analog symbols, followed by time domain interleaving, and so on. Fig. 4 is a schematic diagram of a modified high-order time-interleaved digital-to-analog wireless forwarding architecture of a digital-to-analog forwarding system according to a second embodiment of the present invention, in which the digital symbols and analog symbols are arranged. In this embodiment, when the time-interleaved digital-to-analog wireless forwarding architecture is a high-order architecture, high-order digital symbols and high-order analog symbols generated by separating analog symbols of a previous order are alternately placed.
It should be noted that, different arrangements of the digital and analog symbols have an influence on the result of the later digital signal processing, and the arrangement of one digital and one analog is more beneficial to the damage estimation and compensation of the channel, so that the damage compensation of the analog part can be more accurate. Since the estimation of channel impairments is based on the digital part, the analog part is not able to estimate the impairments, and due to the slowly varying nature of the system impairments, such as polarization rotation and phase noise, adjacent analog signals can be compensated for by the impairment estimation of the digital part in case the impairments in adjacent symbols are not significantly changed.
In the high-order time-interleaved digital-to-analog wireless forwarding architecture, the larger the digital part duty ratio is, the stronger the robustness of the system is. Because the digital part can make decisions, it is a precondition for using digital signal processing algorithms. The larger the digital portion duty cycle, the more advantageous it is to estimate and compensate for channel impairments. The analog part is directly compensated after the damage is estimated based on the digital part, so that the blind equalization of the link damage can be realized, the dynamic damage can be tracked to a certain extent, the practicability of the link system is improved, and the high-fidelity transmission of the wireless signal is realized.
Further, the time-interleaved digital-to-analog wireless forwarding architecture in this embodiment is further configured to perform high-order separation on an analog symbol of a previous order to obtain a high-order digital symbol and a high-order analog symbol, and perform time-domain interleaving on the high-order digital symbol and the high-order analog symbol to obtain an interleaved digital symbol and analog symbol.
It should be noted that, by expanding the time-interleaved digital-to-analog wireless forwarding architecture proposed in this embodiment to a high-order time-interleaved digital-to-analog wireless forwarding architecture, the analog signal generated by the first-order digital-to-analog conversion is separated into digital and analog according to the first-order method, so that the analog signal can be split into analog and digital again. The larger the digital part duty ratio is, the more favorable the estimation and compensation of channel damage are.
Further, in this embodiment, the DSP receiving end is further configured to add the digital symbol of the high order and the analog symbol of the high order to obtain a recovered wireless signal, where the process is:
S Rx_N ＝A Rx +D Rx_1 +D Rx_2 +…+D Rx_N ；
wherein D is Rx_1 D is the digital signal after the first order judgment Rx_2 Is a digital signal after the second order judgment, D Rx_N Is a digital signal after Nth order judgment, A Rx For compensated analog signals, S Rx_N Is the recovered wireless signal.
In a specific implementation, the analog signal generated by the first-order digital-to-analog conversion is subjected to digital-to-analog separation again according to the first-order method, and then the analog signal can be subjected to analog-to-digital separation again to obtain a higher-order digital signal and a higher-order analog signal. The larger the digital portion duty cycle, the more advantageous it is to estimate and compensate for channel impairments.
Further, in this embodiment, the DSP receiving end and the DSP transmitting end are implemented based on a coherent receiver, where the coherent receiver includes a PIN detector and a photo detector with transimpedance amplification.
In this embodiment, considering a high-order architecture, a modified high-order time-interleaved digital-analog wireless preamble architecture is proposed, where an analog part generated in the first order is divided into digital and analog symbols again, and then time-domain interleaving is performed; the analog part of the second order generation is then separated again into digital and analog symbols, followed by time domain interleaving, and so on. The greater the digital fraction, the more robust the system. Because the digital part can make decisions, it is a precondition for using digital signal processing algorithms. The larger the digital portion duty cycle, the more advantageous it is to estimate and compensate for channel impairments. The analog part is directly compensated after the damage is estimated based on the digital part, so that the blind equalization of the link damage can be realized, the dynamic damage can be tracked to a certain extent, the practicability of the link system is improved, and the high-fidelity transmission of the wireless signal is realized.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.
The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.
From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. read-only memory/random-access memory, magnetic disk, optical disk), comprising instructions for causing a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method according to the embodiments of the present invention.
The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.
Claims (10)
1. A digital-to-analog forwarding system, the digital-to-analog forwarding system comprising: a DSP transmitting end, a DSP receiving end and a time interleaving digital-analog wireless forwarding architecture;
the DSP transmitting end is used for carrying out quantization modulation on the wireless signal to be modulated when the wireless signal to be modulated is received, so as to obtain a modulated digital symbol and an analog symbol;
the time-interleaved digital-to-analog wireless front-end architecture is used for performing time-domain interleaving on the modulated digital symbols and analog symbols to obtain interleaved digital symbols and analog symbols, wherein the digital symbols and the analog symbols are alternately placed in the time-interleaved digital-to-analog wireless front-end architecture;
and the DSP receiving end is used for judging and recovering the digital symbols and the analog symbols after interleaving to obtain wireless signals.
2. The digital-to-analog transmission system of claim 1, wherein said time-interleaved digital-to-analog wireless transmission architecture comprises alternating a plurality of digital symbol combinations and a plurality of analog symbol combinations.
3. The digital-to-analog forwarding system of claim 1 wherein when the time-interleaved digital-to-analog wireless forwarding architecture is a higher-order architecture, higher-order digital symbols and higher-order analog symbols generated by the separation of the analog symbols of the previous order are placed alternately.
4. The digital-to-analog forwarding system of claim 1, wherein the DSP transmitting end is further configured to perform quantization operation on a wireless signal to be modulated to obtain a modulated digital symbol, and the process is as follows:
D Tx ＝Q ro (S Tx )；
wherein Q is ro To quantize a quantization factor using a rounding principle, S Tx For the wireless signal to be modulated, D Tx Is a modulated digital symbol.
5. The digital-to-analog forwarding system of claim 4, wherein the DSP transmitting end is further configured to perform a process of obtaining a modulated analog symbol by differencing the wireless signal to be modulated and the modulated digital symbol, the process comprising:
A Tx ＝S Tx -D Tx ；
wherein S is Tx For the wireless signal to be modulated, D Tx For modulated digital symbols, A Tx Is a modulated analog symbol.
6. The digital-to-analog forwarding system of claim 5 wherein said DSP receiver is further configured to perform symbol decisions on said interleaved digital symbols to obtain a decided digital signal;
the DSP receiving end is also used for carrying out damage compensation on the interleaved analog symbols to obtain compensated analog signals.
7. The digital-to-analog forwarding system of claim 6 wherein the DSP receiving end is further configured to add the determined digital signal and the compensated analog signal to obtain a recovered wireless signal, which is:
S Rx ＝A Rx +D Rx ；
wherein D is Rx A as the digital signal after the judgment Rx For compensated analog signals, S Rx Is the recovered wireless signal.
8. The digital-to-analog transmission system of claim 3, wherein said time-interleaved digital-to-analog radio transmission architecture is further configured to perform high-order separation on analog symbols of a previous order to obtain high-order digital symbols and high-order analog symbols, and perform time-domain interleaving on said high-order digital symbols and said high-order analog symbols to obtain interleaved digital symbols and analog symbols.
9. The digital-to-analog forwarding system of claim 8, wherein the DSP receiving end is further configured to add the digital symbol of the higher order and the analog symbol of the higher order to obtain the recovered wireless signal, where:
S Rx_N ＝A Rx +D Rx_1 +D Rx_2 +…+D Rx_N ；
wherein D is Rx_1 D is the digital signal after the first order judgment Rx_2 Is a digital signal after the second order judgment, D Rx_N Is a digital signal after Nth order judgment, A Rx For compensated analog signals, S Rx_N Is the recovered wireless signal.
10. The digital-to-analog forwarding system of any of claims 1-9, wherein the DSP receiving end and the DSP transmitting end are implemented based on a coherent receiver comprising a PIN detector and a photo detector with transimpedance amplification.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311070264.XA CN117061005A (en) | 2023-08-22 | 2023-08-22 | Digital analog forwarding system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311070264.XA CN117061005A (en) | 2023-08-22 | 2023-08-22 | Digital analog forwarding system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117061005A true CN117061005A (en) | 2023-11-14 |
Family
ID=88662393
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311070264.XA Pending CN117061005A (en) | 2023-08-22 | 2023-08-22 | Digital analog forwarding system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117061005A (en) |
-
2023
- 2023-08-22 CN CN202311070264.XA patent/CN117061005A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2667071C1 (en) | Cascade modulation of the waveform with the in line control signal for the high-productive peripheral transit of mobile communication | |
| CN109347562B (en) | CO-OFDM system phase noise optimization compensation method | |
| US6810007B1 (en) | OFDM transmission/receiving system and block encoding method therefor | |
| CN111865432B (en) | Blind phase noise compensation method in CO-FBMC/OQAM system | |
| Chen et al. | Real-Time Generation and Reception of OFDM Signals for $ X $-Band RoF Uplink With Heterodyne Detection | |
| WO2004084466A2 (en) | Method and apparatus for sub sample-per-symbol demodulator for a spectrally efficient waveform with an lpi feature | |
| Wang et al. | SNR improved digital-PCM radio-over-fiber scheme supporting 65536 QAM for mobile fronthaul | |
| Zhang et al. | 14 1Tb/s CPRI-equivalent rate 1024-QAM transmission via combs-cloned self-homodyne WDM digital-analog radio-over-fiber system | |
| CN117061005A (en) | Digital analog forwarding system | |
| da Silva et al. | Experimental Characterization of $10\times 8$ GBd DP-1024QAM Transmission with 8-bit DACs and Intradyne Detection | |
| Yin et al. | Demonstration of 100Gb/s/λ 32QAM-DMT Transmission in Intra-DCI Using 10G-calss EML Modulator and 4-bit DAC | |
| JP2013016978A (en) | Optical communication system and optical communication method | |
| JP2013009023A (en) | Receiving device, communication system, receiving method, and communication method | |
| JP4108554B2 (en) | Digital AGC circuit | |
| CN1926797A (en) | System and method for sending and receiving QAM signal in low signal-noise ratio | |
| Li et al. | Deep Learning-Based End-to-End Bit-Wise Autoencoder for G-Band Fiber-Terahertz Integrated DFT-S-OFDM Communication System | |
| Zhu et al. | 1.02 Tb/s CPRI-Equivalent Rate Direct Detection Transmission Supporting 1024-QAM Using IQ Interleaved Digital-Analog Radio-over-Fiber for Mobile Fronthaul | |
| CN116016081B (en) | Non-cooperative digital communication signal blind demodulation method and system based on two-stage blind separation | |
| CN116582183B (en) | Digital modulation optical fiber radio method | |
| Chen et al. | Digital Coherent Fronthual Employing Sample Bits Interleaving and Uneven 16-QAM | |
| Zhang et al. | 15-Gbaud PAM4 digital mobile fronthaul with enhanced differential pulse coding modulation supporting 122 LTE-A channels with up to 4096QAM | |
| Yin et al. | Demonstration of $100\text {Gb}/\mathrm {s}/\lambda\32\text {QAM} $-DMT Transmission in Intra-DCI Using 10G-calss EML Modulator and 4-bit DAC | |
| Zhu et al. | Efficient SNR Scaling at> 10dB per Extra Bandwidth Using Cascaded Hybrid Digital-Analog Radio-over-Fiber for Fronthaul | |
| Li et al. | DFT-Spread Based PAPR Reduction of OFDM for Short Reach Communication Systems | |
| Ribeiro et al. | On the design of robust multi-user receivers for base station cooperation systems |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |