WO2016165486A1

WO2016165486A1 - Transmitter and signal output method

Info

Publication number: WO2016165486A1
Application number: PCT/CN2016/074298
Authority: WO
Inventors: 孙泰然; 陶俊
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-09-06
Filing date: 2016-02-22
Publication date: 2016-10-20
Also published as: CN106506014B; CN106506014A

Abstract

Disclosed are a transmitter and a signal output method. The transmitter comprises: an encoder modulator, a digital up-conversion module, a high-speed serial transmitter module, a bandpass filter, a power amplifier module, and a passive combiner module. By means of the technical solution of the present invention, the encoding efficiency is greatly improved, the digital predistortion of a system is easily realized, and the structure complexity and costs of the transmitter are greatly reduced, thereby facilitating integration and commercial use; in addition, the adjustment accuracy of branch time delay is relatively high, thereby being beneficial to the modulation of branch balance.

Description

Transmitter and signal output method

Technical field

The present invention relates to the field of mobile communications, and in particular to a transmitter and a signal output method.

Background technique

With the successful commercialization of the LTE-Advanced (LTE-A), the next-generation 5G standard is poised for growth, and the demand for mobile RF systems by various equipment manufacturers and operators is also constantly upgrading. Currently, there are more than 40 total frequency bands of 2G, 3G, and 4G LTE in the world, and in order to acquire frequency band resources, technologies such as Carrier Aggregation (CA) and Multi-Antenna (MIMO) are required, and wireless base stations are required to have broadband. Features such as wide, high efficiency, and flexible configurability greatly increase the complexity of the RF front end. An efficient transmitter based on Linear Amplification with Nonlinear Components (LINC) is an ideal solution to meet the future evolution of mobile communication systems.

Modern communication systems use non-constant envelope modulation. Traditional transmitter schemes use power back-off to meet their linearity requirements, resulting in severely reduced transmitter efficiency. Since LINC technology (linear amplification technology for nonlinear components) has been proposed, it is considered to be one of the most promising transmitter technologies due to its high efficiency and linearity. The coding modulation technique mainly involved is called Outphasing technology. It was proposed in 1935. The idea is to split the input signal S into two-way constant envelope signals S1 and S2, and then use nonlinear high efficiency. The power amplifier (PA) amplifies the constant envelope signal and finally outputs it at the combiner. 1 is a schematic diagram of a basic architecture of a LINC transmitter in the prior art. As shown in FIG. 1, the baseband digital processor decomposes a single peak-to-average ratio signal into two constant envelope signals, and outputs them through a dac and an IQ modulator. For the nonlinear power amplifier, after entering the combiner, the original signal is restored. The decomposition principle is shown in Fig. 2. The band-limited signal S(t)=r(t)·e ^{-jθ(t) of the} amplitude modulation phase modulation characteristic, 0≤r(t)≤r _max , where r _max is the input The maximum value of the signal amplitude is separated by a signal separator (Signal Components Separator, SCS for short) to generate the following two signals:

make

In the research and practice of traditional LINC technology, the inventors found that the prior art has the following deficiencies:

1, the structure is complex, including multiple analog components, such as the need for digital-to-analog converters (DAC), and analog modulators, even with IC technology is difficult to integrate, package.

2. Due to the high cost caused by using dac and a large number of analog links, especially due to the bandwidth widening after using the outphasing algorithm, the bandwidth requirement for dac is also greatly improved, and it is necessary to adopt a better performance dac, which will inevitably bring about cost increase.

3. Due to the complexity of the link, a large amount of nonlinearity will inevitably be introduced. In addition, the link balance is difficult to control, which inevitably leads to a large increase in the nonlinearity of the output.

Summary of the invention

In view of the above problems in the prior art, the present invention has been made in order to provide a transmitter and signal output method that overcomes the above problems or at least partially solves the above problems.

An embodiment of the present invention provides a transmitter, including:

A coded modulator configured to convert an input baseband signal into two constant envelope signals and convert the two constant envelope signals from a multi-bit signal to a single bit by digital signal modulator DSM encoding and pulse width modulator PWM encoding signal;

The digital up-conversion module is configured to up-convert two single-bit signals outputted by the code modulator in the digital domain, move two single-bit signals to a carrier frequency, and combine the single-bit IQ complex signals of each single-bit signal For a single bit real signal, output to a high speed serial transmitter module;

A high speed serial transmitter module configured to convert two constant envelope signals from a digital signal to an analog signal and output to a band pass filter;

A bandpass filter configured to filter out the out-of-band signal modulated by the code modulator and recover the two-way constant envelope signal after the out-of-phase decomposition, wherein the passband bandwidth of the bandpass filter is a code modulator conversion The decomposition bandwidth of the two-way constant envelope signal;

The power amplifier module is configured to perform power amplification on the two constant envelope signals output by the band pass filter;

The passive combination module is configured to combine and output two constant envelope signals output by the power amplifier module.

The code modulator, the digital up-conversion module, the high-speed serial transmitter module, the band-pass filter, the power amplifier module, and the passive combination module may adopt central processing when performing processing (CPU, Central Processing Unit), digital signal processor (DSP, Digital Singnal Processor) or Programmable Array (FPGA).

The embodiment of the invention further provides a signal output method, including:

The coded modulator converts the input baseband signal into two constant envelope signals, and converts the two constant envelope signals from the multi-bit signal to the single-bit signal through digital signal modulator DSM encoding and pulse width modulator PWM coding;

The digital up-conversion module upconverts two single-bit signals output by the coded modulator in the digital domain, moves the two single-bit signals to the carrier frequency, and combines the single-bit IQ complex signals of each single-bit signal into a single bit. Real signal, output to high speed serial transmitter module;

The high-speed serial transmitter module converts two constant envelope signals from digital signals to analog signals and outputs them to a band-pass filter. The band-pass filter filters out the out-of-band signals modulated by the code modulator and recovers the difference. The phase-decomposed two-way constant envelope signal is input to the power amplifier module, wherein the passband bandwidth of the bandpass filter is a decomposition bandwidth of the two modulators of the constant envelope signal converted by the code modulator;

The power amplifier module power-amplifies and inputs two constant envelope signals output from the band pass filter To the passive combination module, the passive combination module combines and outputs the two constant envelope signals output by the power amplifier module.

By adopting the embodiment of the invention, the original LINC transmitter is modified, the concept of the digital transmitter is introduced, the transmitter link is simplified under the condition of ensuring high efficiency, and the original analog-to-digital converter is replaced by using digital modulation technology. IQ modulator and a large number of RF links, its structural complexity, transmitter cost will be greatly reduced, easy to integrate and commercial; in addition, the higher frequency of the digital domain output signal makes the adjustment accuracy of the branch delay higher, which is beneficial to the branch balance. Sexual modulation. Compared with the digital transmitter directly using PWM/DSM modulation, the technical solution of the embodiment of the present invention can greatly improve the coding efficiency because the out-of-band signal can be filtered out before the power amplifier, and at the combined output, due to the speciality of the outphasing algorithm. Sex, out-of-band noise is cancelled, making digital pre-distortion of the system easy to implement.

The above description is only an overview of the technical solutions of the present invention, and the above-described and other objects, features and advantages of the present invention can be more clearly understood. Specific embodiments of the invention are set forth below.

DRAWINGS

Various other advantages and benefits will become apparent to those skilled in the art from a The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting. Throughout the drawings, the same reference numerals are used to refer to the same parts. In the drawing:

1 is a schematic diagram of a basic architecture of a LINC transmitter in the prior art;

2 is a vector diagram of an OUTPHASING decomposition in the prior art;

3 is a schematic structural diagram of a transmitter according to an embodiment of the present invention;

4 is a schematic diagram of the principle of an efficient transmitter according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a transmitter according to an embodiment of the present invention; FIG.

6 is a schematic structural diagram of an OUTPHASING processing module according to an embodiment of the present invention;

7 is a schematic structural diagram of a DSM/PWM encoding module according to an embodiment of the present invention;

FIG. 8 is a flowchart of a signal output method according to an embodiment of the present invention.

detailed description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the embodiments of the present invention have been shown in the drawings, the embodiments Rather, these embodiments are provided so that this disclosure will be more fully understood and the scope of the disclosure will be fully disclosed.

In order to solve the above problems in the prior art, an embodiment of the present invention provides a code modulator implemented by combining Outphasing and DSM/PWM, and a single-bit all-digital transmitter device composed thereof: by Outphasing decomposition at a low sampling rate , high sampling rate on DSM / PWM encoding, modulation. The constant envelope signal is recovered by the filter and output to the high efficiency LINCPA. The invention will be further described in detail below with reference to the drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Device embodiment:

According to an embodiment of the present invention, a transmitter is provided, and FIG. 3 is a schematic structural diagram of a transmitter according to an embodiment of the present invention. As shown in FIG. 3, a transmitter according to an embodiment of the present invention includes: a code modulator (ie, a subordinate) Digital coded modulator 30), digital up-conversion module 31, high-speed serial transmitter module 32, bandpass filter 33, power amplifier module (ie, LINCPA described below) 34, and passive combining module 35, in the following embodiments of the present invention Each module is described in detail.

The code modulator 30 is configured to convert the input baseband signal into two constant envelope signals, and convert the two constant envelope signals from the multi-bit signal to a single by the digital signal modulator DSM encoding and the pulse width modulator PWM encoding. The bit signal; the code modulator 30 specifically includes: a heterogeneous processing module and an encoding module, specifically:

a heterogeneous processing module configured to oversample an input baseband signal and pass the signal The number separation algorithm performs out-of-phase decomposition to convert one baseband signal into two constant envelope signals; the heterogeneous processing module is specifically configured to extract the phase and amplitude information of the input baseband signal by using a coordinate rotation digital calculation method, and The amplitude information is converted into phase information, and finally two kinds of phase information are input to the phase modulator, and two constant envelope signals are output.

The coding module is configured to perform oversampling and noise shaping processing on the two constant envelope signals by DSM coding, perform PWM processing on the signal after the noise shaping processing, and perform parallel-to-serial conversion. The coding module specifically includes: a DSM coding module and a PWM coding module, specifically:

The DSM encoding module is configured to perform oversampling and noise shaping processing on the two constant envelope signals by DSM encoding, and compress the bits of the two constant envelope signals from M bits to N bits, where 1<N<M;

The PWM coding module is configured to perform a table lookup operation by using two N-bit constant envelope signals as a table lookup address, and perform parallel-to-serial conversion of the data, and output two single-bit signals according to the result of the look-up table (the single-bit signal is IQ complex signal).

The digital up-conversion module 31 is configured to up-convert the two single-bit signals output by the code modulator 30 in the digital domain, to move the two single-bit signals to the carrier frequency, and to multiply the single-bit IQ of each single-bit signal. The signals are combined into a single bit real signal and output to the high speed serial transmitter module 32;

The high speed serial transmitter module 32 is configured to convert two constant envelope signals from a digital signal to an analog signal, and output to the band pass filter 33;

The bandpass filter 33 is configured to filter out the out-of-band signal modulated by the code modulator and recover the two-way constant envelope signal after the out-of-phase decomposition, wherein the passband bandwidth of the bandpass filter is The code modulator converts the decomposition bandwidth of two constant envelope signals;

That is to say, in order to make the power amplifier output efficiently, the band-pass filter requires the filtered signal to be a constant envelope. In order to improve the overall system efficiency, it is required to filter out the out-of-band signal as much as possible. Therefore, the passband bandwidth of the bandpass filter is required. The outphasing decomposition bandwidth for the out-of-phase processing module.

The power amplifier module 34 is configured to perform power amplification on the two constant envelope signals output by the band pass filter 33;

The passive combining module 35 is configured to combine and output the two constant envelope signals output by the power amplifier module 34. The passive combination module 35 includes an isolation combiner or a non-isolated combiner.

The above technical solutions of the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

4 is a schematic diagram of the principle of an efficient transmitter according to an embodiment of the present invention. As shown in FIG. 4, the system mainly includes three parts: a digital code modulator (Digital Encode Modulator), a filter, and a LINCPA. The digital modulator performs digital modulation in the digital domain, generates a modulated digital signal, and generates two constant envelope signals to drive LINCPA through filtering. The LINCPA mainly works in a saturated region, and has characteristics of high efficiency, flexibility, reconfigurability, and high linearity.

There are three main types of digital transmitter coded modulators: OUTPHASING decomposition, digital-sigma modulator (DSM) and pulse-width modulator (PWM).

OUTPHASING is decomposed and the peak-to-average ratio signal (the envelope varies greatly) is converted into two constant envelope signals by the Signal Separation Algorithm (SCS). Although both paths generate a noise signal that occupies the decomposition bandwidth, the noise cancels each other after the LINCPA combines.

DSM can modulate multi-bit input signals into low-bit outputs by oversampling (ie, sampling rates are many times higher than signal bandwidth) and noise shaping techniques (quantization noise is mainly distributed out-of-band with low in-band noise). The signal can maintain the signal to noise ratio (SNR) performance of the signal.

The PWM compares the signal with a comparison wave of a certain frequency, and generates a low-bit or single-bit output signal according to the comparison result, and is also a signal coding modulation technique.

The signal-separation algorithm (SCS) can change the variable envelope signal into two constant envelope signals, and then perform the latter two coding techniques (DSM/PWM) on the two signals, and the constant-envelope multi-bit signal, Convert to a single-bit signal, then pass the bandpass filter and enter LINCPA. And tradition Compared with the transmitter architecture, the DAC (Digital to Analog Converter) and the analog up-conversion structure can be omitted by (DSM/PWM), and then the constant envelope signal can be recovered by the filter to further improve the coding efficiency. Combined with high efficiency LINCPA, it achieves high power amplifier efficiency.

FIG. 5 is a schematic structural diagram of a transmitter according to an embodiment of the present invention. As shown in FIG. 5, the method specifically includes:

The OUTPHASING processing module oversamples the baseband signal, and at the lower sampling rate, performs OUTPHASING decomposition on the signal, and converts one signal into two constant envelope signals, both of which contain information of the original signal, and phase The opposite noise signal, when passing through the combiner, the opposite phase noise signals cancel each other out, thereby recovering the original signal.

As shown in FIG. 5, the 502 module is an OUTPHASING processing module, and the amplitude information of the input peak-to-average ratio signal is converted into additional phase information of the two sub-signals S1 and S2. Wherein, as shown in FIG. 6, in the OUTPHASING processing module, 601 uses the cordic algorithm to extract the phase and amplitude information of the input signal, converts the amplitude information into phase information through the 602 lookup table, and finally inputs the two phase information to the phase modulator. 603, output two phase modulation signals of Hengbao.

The DSM\PWM processing module, the DSM processing module mainly performs oversampling and noise shaping processing on the previous two M-bit constant envelope data, and compresses it to N bits (M>N) to ensure that the near-end noise floor is sufficiently low. Then, the table-and-table method is used to realize the coding and modulation of the PWM signal. The input N-bit data is used as the address of the lookup table, and the content outputted after the look-up table is used as the PWM pulse width modulation signal. It should be noted that the PWM processing module realizes parallel-to-serial conversion of data in the process of implementing input data look-up, converting N-bit data into single-bit output, and multi-bit output in multi-level applications. However, the number of bits is less than N, and the data rate is also increased by 2^N times of the principle.

Specifically, as shown in FIG. 5, the 503 module is a DSM/PWM encoding module, and encodes and modulates a multi-bit signal of an input signal to perform noise shaping processing, and the input signal is M-bit data, and the output signal is an N-bit signal (M >N). Wherein, as shown in FIG. 7, 701 is DSM encoding. Module, which performs shaping filtering on quantization noise, which can be first-order, second-order or even higher-order noise shaping, and the output is an N-bit model. The 702 module is a PWM module, which performs PWM processing on the input signal and implements parallel-to-serial conversion. The input signal is an N-bit signal, and the output signal is a single bit.

The digital up-conversion module 504 implements a "sampling rate/4" up-conversion function in the digital domain, and combines the IQ complex signal into a single-channel real-signal output while moving the signal to the carrier frequency, wherein the sampling rate refers to the PWM processing module. The data rate of the output signal.

The high speed serial transmitter (Serdes) module 505 takes the signal from digital to analog. Different from the traditional digital-to-analog conversion of DAC devices, the digital logic circuit chip integrated high-speed serial transmitter (Serdes) is used to convert digital signals to analog signals.

The two-way bandpass filter 506 filters out the out-of-band harmonics generated by the PWM/DSM modulation, and retains the branch signal decomposed by the OUTPHASING in the band to restore the analog signal of the constant envelope.

Power amplifier module 507, LINCPA mainly refers to the two-way consistency of high-efficiency power amplifiers (C, D, E, F), this power amplifier module works in saturation state, driven by constant envelope signal, the efficiency is very high.

The passive combining module 508 is mainly an isolated and non-isolated combiner realized by a coupling transmission line. Considering the improvement of the combining efficiency, the Cherix combiner with the compensation angle can be used according to the peak-to-average ratio of the input signal.

The above technical solutions of the embodiments of the present invention are described in detail below with reference to examples.

Take the 10M signal with an input peak-to-average ratio of 7db as an example, and decompose it into two signals at the sampling rate Fs=61.44Msps (to ensure the constant envelope characteristic requirement, the sub-bandwidth is more than 6 times the signal bandwidth), and its data bit width It is 16bits. After oversampling, the sampling rate is Fs=245.76Msps, and after DSM processing, the bit width is compressed to 4bits. After the table lookup process, single-bit data is output, and the sampling rate is increased to Fs*2^4=3932.16Msps.

In the structure shown in Figure 7, the OUTPHASING and DSM operating operating clock rates are relatively low, and high-order DSMs can be used to further suppress near-end noise. The PWM module is composed of A very small lookup table implementation, very high precision, and the resulting signal performance is also very good.

After the PWM output signal is digitally upconverted, the sampling rate is increased to Fs=7864.32Msps, and the carrier frequency is Fc=Fs/4=1966.08MHz.

The multi-channel single-bit signal in the digital domain can be converted from digital to analog domain by multi-channel Serdes, and then bandpass filtered with a passband bandwidth of 60M. The OUTPHASING constant envelope signal is restored to the high-efficiency power amplifier module of the subsequent stage to achieve power amplification.

Afterwards, the high efficiency (with compensation angle) Cherix isolation combiner combines to improve the combined efficiency, which is consistent with the traditional LINCPA. In addition, the digital part has a feedback branch, due to the special nature of OUTPHASING decomposition synthesis, and band pass filtering. The filter filters out the out-of-band modulation signal so that digital pre-distortion can be done before digital modulation (before OUTPHASING decomposition) in a manner consistent with traditional architecture.

Compared with the conventional LINCPA using OUTPHASING decomposition, the two have similar high efficiency (in the case of using the Cherix combiner with compensation angle), but the technical solution of the embodiment of the present invention is no longer needed in the improved architecture. Analog-to-digital converters (dac), IQ modulators, and a large number of RF links, the complexity of the structure, the cost of the transmitter will be greatly reduced, easy to integrate, commercial, and the higher frequency of the digital domain output signal makes the adjustment of the branch delay High precision, which is conducive to the modulation of the branch balance. Compared with the digital transmitter directly using PWM/DSM modulation, since the out-of-band signal can be filtered out before the power amplifier, the coding efficiency is greatly improved, and at the combined output, due to the particularity of the OUTPHASING algorithm, the out-of-band noise is Offseting makes the digital predistortion of the system easy to implement.

Method embodiment:

According to an embodiment of the present invention, a signal output method is provided based on the transmitter in the above device embodiment, and FIG. 8 is a flowchart of a signal output method according to an embodiment of the present invention. As shown in FIG. 8, the present invention is implemented according to the present invention. The signal output method of the example includes the following processing:

Step 801, the code modulator converts the input baseband signal into two constant envelope signals, and communicates Over digital signal modulator DSM encoding and pulse width modulator PWM encoding converts two constant envelope signals from a multi-bit signal to a single-bit signal;

Specifically, step 801 includes the following processing:

Step 1: The heterogeneous processing module oversamples the input baseband signal, and performs heterogeneous decomposition by the signal separation algorithm to convert one baseband signal into two constant envelope signals; specifically, the heterogeneous processing module uses coordinate rotation The digital calculation method extracts the phase and amplitude information of the input baseband signal, converts the amplitude information into phase information by looking up the table, and finally inputs the two phase information to the phase modulator to output two constant envelope signals.

Step 2: The encoding module oversamples and forms the two-way constant envelope signal by DSM encoding, performs PWM processing on the signal after the noise shaping process, and performs parallel-to-serial conversion. Specifically, the following processing is included:

The DSM encoding module oversamples and noises the two constant envelope signals by DSM encoding, and compresses the bits of the two constant envelope signals from M bits to N bits, where 1<N<M;

The PWM coding module performs a table lookup operation by using two N-bit constant envelope signals as a table lookup address, and performs parallel-to-serial conversion of the data. According to the result of the look-up table, two single-bit signals are outputted (the single-bit signal is an IQ complex number). signal).

Step 802, the digital up-conversion module up-converts two single-bit signals outputted by the code modulator in the digital domain, moves two single-bit signals to a carrier frequency, and converts a single-bit IQ complex signal in each single-bit signal. Merged into a single-bit real signal, output to a high-speed serial transmitter module;

Step 803, the high-speed serial transmitter module converts two constant envelope signals from a digital signal into an analog signal, and outputs the signal to a band pass filter, and the band pass filter filters out the out-of-band signal modulated by the code modulator, and Restore the two-way constant envelope signal after the heterogeneous decomposition, and input it to the power amplifier module;

Step 804, the power amplifier module power-amplifies the two-way constant envelope signals output by the band-pass filter, and inputs the signals to the passive combining module, and the passive combining module outputs the two-way constant envelope of the power amplifier module. The signals are combined and output. The passive combination module includes: an isolation combiner, or a non-isolated combiner.

As shown in Fig. 4, the digital modulator performs digital modulation in the digital domain to generate a modulated digital signal, and generates two constant envelope signals to drive LINCPA through filtering. The LINCPA mainly works in a saturated region, and has high efficiency, flexibility and reconfigurability. High linearity and other characteristics.

The signal-separation algorithm (SCS) can change the variable envelope signal into two constant envelope signals, and then perform the latter two coding techniques (DSM/PWM) on the two signals, and the constant-envelope multi-bit signal, Convert to a single-bit signal, then pass the bandpass filter and enter LINCPA. Compared with the traditional transmitter architecture, the DAC (Digital to Analog Converter) and the analog up-conversion structure can be omitted by (DSM/PWM), and then the constant envelope signal can be recovered by the filter to further improve the coding efficiency. Combined with high efficiency LINCPA, it achieves high power amplifier efficiency.

FIG. 5 is a detailed structural diagram of a transmitter according to an embodiment of the present invention, as shown in FIG. include:

The OUTPHASING processing module oversamples the baseband signal, and at the lower sampling rate, the signal is subjected to OUTPHASING decomposition, and one signal is converted into two constant envelope signals, both of which contain the original signal information and the opposite phase. The noise signal, when passing through the combiner, the opposite phase noise signals cancel each other out, thereby recovering the original signal.

The DSM\PWM processing module mainly performs oversampling and noise shaping processing on the previous two M-bit constant envelope data, and compresses it to N bits (M>N) to ensure that the near-end noise floor is sufficiently low. Then, the table-and-table method is used to realize the coding and modulation of the PWM signal. The input N-bit data is used as the address of the lookup table, and the content outputted after the look-up table is used as the PWM pulse width modulation signal. It should be noted here that the PWM processing module realizes the parallel-to-serial conversion of data in the process of implementing the input data look-up table, and converts the N-bit data into a single-bit output.

Specifically, as shown in FIG. 5, the 503 module is a DSM/PWM encoding module, and encodes and modulates a multi-bit signal of an input signal to perform noise shaping processing, and the input signal is M-bit data, and the output signal is an N-bit signal (M >N). Wherein, as shown in FIG. 7, 701 is a DSM encoding module, and the module performs shaping filtering on the quantization noise, which may be first-order, second-order or even higher-order noise shaping, and the output is an N-bit model. The 702 module is a PWM module, which performs PWM processing on the input signal and implements parallel-to-serial conversion. The input signal is an N-bit signal, and the output signal is a single bit.

The digital up-conversion module implements the “sampling rate/4” up-conversion function in the digital domain, and combines the IQ complex signal into a single-channel real-signal output while moving the signal to the carrier frequency. The sampling rate refers to the PWM processing module output signal. Data rate.

The high-speed serial transmitter (Serdes) module takes the signal from digital to analog. Different from the traditional digital-to-analog conversion of DAC devices, the digital logic circuit chip integrated high-speed serial transmitter (Serdes) is used to convert digital signals to analog signals.

The two-band bandpass filter filters the out-of-band harmonics generated by the PWM/DSM modulation, while retaining the branch signal decomposed by the OUTPHASING in the band, and restores the analog signal into a constant envelope.

The power amplifier module LINCPA mainly refers to two well-consistent high-efficiency power amplifiers (C, D, E, F). This power amplifier module works in a saturated state and is driven by a constant envelope signal with high efficiency.

The passive combination module is mainly an isolated and non-isolated combiner realized by a coupling transmission line. Considering the improvement of the combining efficiency, the Cherix combiner with the compensation angle can be used according to the peak-to-average ratio of the input signal.

In the structure shown in Figure 7, the OUTPHASING and DSM operating operating clock rates are relatively low, and high-order DSMs can be used to further suppress near-end noise. The PWM module is implemented by a very small lookup table, which is very accurate and produces very good signal performance.

Afterwards, the high efficiency (with compensation angle) Cherix isolation combiner combines to improve the efficiency of the combination, which is consistent with the traditional LINCPA. In addition, the digital part also has a feedback branch due to OUTPHASING. The special nature of the decomposition synthesis, as well as the bandpass filter filtering out the out-of-band modulation signal, allows digital pre-distortion to be done before digital modulation (before OUTPHASING decomposition) in a manner consistent with traditional architectures.

Compared with the conventional LINCPA using OUTPHASING decomposition, the two have similar high efficiency (both use the Cherix combination with compensation angle), but the analogy of the technical solution of the embodiment of the present invention no longer needs to use analog-to-digital conversion. (dac), IQ modulator and a large number of RF links, its structural complexity, transmitter cost will be greatly reduced, easy to integrate, commercial, and the higher frequency of the digital domain output signal makes the adjustment accuracy of the branch delay higher Conducive to the modulation of the branch balance. Compared with the digital transmitter directly using PWM/DSM modulation, since the out-of-band signal can be filtered out before the power amplifier, the coding efficiency is greatly improved, and at the combined output, due to the particularity of the OUTPHASING algorithm, the out-of-band noise is Offseting makes the digital predistortion of the system easy to implement.

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general purpose systems can also be used with the teaching based on the teachings herein. The structure required to construct such a system is apparent from the above description. Moreover, the invention is not directed to any particular programming language. It is to be understood that the invention may be embodied in a variety of programming language, and the description of the specific language has been described above in order to disclose the preferred embodiments of the invention.

In the description provided herein, numerous specific details are set forth. However, it is understood that the embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of the description.

Similarly, it should be understood that in order to streamline the present disclosure and to help understand one of the various inventive aspects In the above description of the exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description. However, the method disclosed is not to be interpreted as reflecting the intention that the claimed invention requires more features than those recited in the claims. Rather, as the following claims reflect, inventive aspects reside in less than all features of the single embodiments disclosed herein. Therefore, the claims following the specific embodiments are hereby explicitly incorporated into the embodiments, and each of the claims as a separate embodiment of the invention.

Those skilled in the art will appreciate that the modules in the client in the embodiment can be adaptively changed and placed in one or more clients different from the embodiment. The modules in the embodiments can be combined into one module, and further they can be divided into a plurality of sub-modules or sub-units or sub-components. In addition to such features and/or at least some of the processes or units being mutually exclusive, any combination of the features disclosed in the specification, including the accompanying claims, the abstract and the drawings, and any methods so disclosed, or All processes or units of the client are combined. Each feature disclosed in this specification (including the accompanying claims, the abstract and the drawings) may be replaced by alternative features that provide the same, equivalent or similar purpose.

In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features that are included in other embodiments and not in other features, combinations of features of different embodiments are intended to be within the scope of the present invention. Different embodiments are formed and formed. For example, in the following claims, any one of the claimed embodiments can be used in any combination.

The various component embodiments of the present invention may be implemented in hardware, or in a software module running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or digital signal processor (DSP) can be used in practice to implement one of some or all of the components loaded with the ordered web address in accordance with an embodiment of the present invention. Some or all of the features. The invention can also be implemented as a device or device program (e.g., a computer program and a computer program product) for performing some or all of the methods described herein. Such a program implementing the invention may be stored on a computer readable medium or may be in the form of one or more signals. Such signals may be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

It is to be noted that the above-described embodiments are illustrative of the invention and are not intended to be limiting, and that the invention may be devised without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as a limitation. The word "comprising" does not exclude the presence of the elements or steps that are not recited in the claims. The word "a" or "an" The invention can be implemented by means of hardware comprising several distinct elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means can be embodied by the same hardware item. The use of the words first, second, and third does not indicate any order. These words can be interpreted as names.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Industrial applicability

Claims

A transmitter comprising:

a coded modulator configured to convert the input baseband signal into two constant envelope signals and convert the two constant envelope signals from the multi-bit signal to a digital signal modulator DSM code and a pulse width modulator PWM code to Single bit signal

a digital up-conversion module configured to upconvert two single-bit signals output by the code modulator in a digital domain, to move the two single-bit signals to a carrier frequency, and to single-bit each single-bit signal The IQ complex signals are combined into a single-bit real signal that is output to the high-speed serial transmitter module;

a high speed serial transmitter module configured to convert the two constant envelope signals from a digital signal to an analog signal and output the signal to a band pass filter;

a band pass filter configured to filter out the out-of-band signal modulated by the code modulator and recover the two-way constant envelope signal after the out-of-phase decomposition, wherein the passband bandwidth of the band pass filter is The coded modulator converts the decomposition bandwidth of the two constant envelope signals;

a power amplifier module configured to perform power amplification on two constant envelope signals output by the band pass filter;

The passive combining module is configured to combine and output the two constant envelope signals output by the power amplifier module.
The transmitter of claim 1 wherein said code modulator comprises:

The out-of-phase processing module is configured to oversample the input baseband signal, and perform heterogeneous decomposition by the signal separation algorithm to convert the one baseband signal into two constant envelope signals;

The encoding module is configured to perform oversampling and noise shaping processing on the two constant envelope signals by DSM encoding, perform PWM processing on the signal after the noise shaping processing, and perform parallel-to-serial conversion.
The transmitter of claim 2, wherein the out-of-phase processing module is specifically configured to: extract phase and amplitude information of the input baseband signal using a coordinate rotation digital calculation method, The look-up table converts the amplitude information into phase information, and finally inputs the two phase information to the phase modulator to output two constant envelope signals.
The transmitter of claim 2, wherein the encoding module comprises:

a DSM encoding module configured to perform oversampling and noise shaping processing on the two constant envelope signals by DSM encoding, and compress the bits of the two constant envelope signals from M bits to N bits, where 1<N <M;

The PWM coding module is configured to perform a table lookup operation by using two N-bit constant envelope signals as a table lookup address, and perform parallel-to-serial conversion of the data, and according to the result of the look-up table, two single-bit signals are output.
The transmitter of claim 1 wherein said passive combining module comprises: an isolation combiner, or a non-isolated combiner.
A signal output method includes:

The coded modulator converts the input baseband signal into two constant envelope signals, and converts the two constant envelope signals from a multi-bit signal to a single-bit signal by digital signal modulator DSM coding and pulse width modulator PWM coding. ;

The digital up-conversion module upconverts two single-bit signals output by the coded modulator in a digital domain, moves the two single-bit signals to a carrier frequency, and converts a single-bit IQ complex signal of each single-bit signal Merged into a single-bit real signal, output to a high-speed serial transmitter module;

The high-speed serial transmitter module converts the two constant envelope signals from a digital signal to an analog signal, and outputs the signal to a band pass filter, which filters out the out-of-band signal modulated by the code modulator and recovers The two-way constant envelope signal after the out-of-phase decomposition is input to the power amplifier module, wherein the passband bandwidth of the band-pass filter is a decomposition bandwidth of the two modulators of the constant-envelope signal converted by the code modulator;

The power amplifier module power-amplifies two constant envelope signals output by the band pass filter, and inputs the signals to the passive combining module, and the passive combining module outputs the two-way constant package of the power amplifier module The signal is combined and output.
The method of claim 6 wherein said code modulator converts the input baseband signal into two constant envelope signals and combines said two paths by digital signal modulator DSM encoding and pulse width modulator PWM encoding The conversion of the constant envelope signal from the high bit signal to the low bit signal specifically includes:

The out-of-phase processing module oversamples the input baseband signal, and performs heterogeneous decomposition by the signal separation algorithm to convert the one baseband signal into two constant envelope signals;

The coding module oversamples and forms the two-way constant envelope signal by DSM coding, performs PWM processing on the signal after the noise shaping process, and performs parallel-to-serial conversion.
The method according to claim 7, wherein the out-of-phase processing module oversamples the input baseband signal, and performs heterogeneous decomposition by a signal separation algorithm to convert the one baseband signal into two constant envelope signals. include:

The out-of-phase processing module uses the coordinate rotation digital calculation method to extract the phase and amplitude information of the input baseband signal, converts the amplitude information into phase information by looking up the table, and finally inputs the two phase information to the phase modulator to output two constant envelopes. signal.
The method according to claim 7, wherein the encoding module oversamples and forms the two-way constant envelope signal by DSM encoding, performs PWM processing on the signal after the noise shaping process, and performs parallel-to-serial conversion. include:

The DSM encoding module performs oversampling and noise shaping processing on the two constant envelope signals by DSM encoding, and compresses the bits of the two constant envelope signals from M bits to N bits, where 1<N<M;

The PWM coding module performs a table lookup operation by using two N-bit constant envelope signals as a table lookup address, and performs parallel-to-serial conversion of the data, and according to the result of the look-up table, two single-bit signals are output.
The method of claim 6 wherein said passive combining module comprises: an isolation combiner, or a non-isolated combiner.