TW201539993A

TW201539993A - Signal modulation method and signal modulation circuit and transceiver using the same

Info

Publication number: TW201539993A
Application number: TW103113430A
Authority: TW
Inventors: Kang-Chun Peng; Chan-Hung Lee; Yen-Ju Lu; Chih-Hung Huang
Original assignee: Univ Nat Kaohsiung 1St Univ Sc
Priority date: 2014-04-11
Filing date: 2014-04-11
Publication date: 2015-10-16

Abstract

A signal modulation method for restraining a quantization noise and a signal modulation circuit and a transceiver using the same are provided. The signal modulation method includes following steps: providing a frequency synthesizer for generating a oscillating signal according to a reference frequency signal and performing frequency dividing to the oscillating signal according to a frequency divided control signal, obtained by performing a quantization process, and thus generating a frequency divided signal as a feedback signal of the frequency synthesizer; generating a quantization error signal by the frequency synthesizer; providing a baseband processing unit for receiving a input signal and the quantization error signal and performing a pre-distortion process to the input signal and the quantization error signal, and thus generating a set of orthogonal pre-distortion signals; and providing a modulation unit for receiving the pre-distortion signals and the oscillating signal and modulating the pre-distortion signals according to the oscillating signal, and thus generating a output signal.

Description

訊號調變方法及應用其之訊號調變電路與收發機 Signal modulation method and signal modulation circuit and transceiver thereof

本發明是有關於一種訊號調變方法及其應用，且特別是有關於一種具量化雜訊抑制的訊號調變方法及應用其之訊號調變電路與收發機。 The invention relates to a signal modulation method and an application thereof, and particularly relates to a signal modulation method with quantization noise suppression and a signal modulation circuit and a transceiver thereof.

近年來，隨著無線科技的蓬勃發展，造就了無線通訊在人們的日常生活中的迅速擴展，例如：行動電話、無線區域網路(Wireless Local Area Network,WLAN)、藍芽(Bluetooth)、超寬帶技術(Ultra Wide Band,UWB)、工業科學與醫療通信(Industrial Scientific and medical,ISM)與全球互通微波存取(Worldwide Interoperability for Microwave Access,WiMAX)等。因此，為了因應在無線通信系統中本地振盪訊號的要求以及通信通道選擇的需求，進而衍生出頻率合成器的發展與應用。 In recent years, with the rapid development of wireless technology, wireless communication has rapidly expanded in people's daily lives, such as: mobile phones, wireless local area network (WLAN), Bluetooth, ultra Ultra Wide Band (UWB), Industrial Scientific and Medical (ISM) and Worldwide Interoperability for Microwave Access (WiMAX). Therefore, in order to meet the requirements of local oscillation signals in the wireless communication system and the selection of communication channels, the development and application of frequency synthesizers are derived.

詳細來說，頻率合成器提供了訊號調變電路調變時所需本地振盪訊號，由此可見，本地振盪訊號的優劣是決定訊號傳輸品質的重要因素。本地振盪訊號的頻譜純淨度不僅影響了傳輸資料的正確性，對系統通道的品質更具有關鍵性的影響。尤其是在多載波系統中，例如正交分頻多工(Orthogonal Frequency Division Modulation,OFDM)通訊系統，高密度的正交載波對本地振盪源的頻譜純淨度有著更嚴苛的要求。 In detail, the frequency synthesizer provides the local oscillation signal required for the modulation of the signal modulation circuit. It can be seen that the quality of the local oscillation signal is an important factor determining the quality of the signal transmission. The spectral purity of the local oscillator signal not only affects the transmission resources. The correctness of the material has a more critical impact on the quality of the system channel. Especially in multi-carrier systems, such as Orthogonal Frequency Division Modulation (OFDM) communication systems, high-density orthogonal carriers have more stringent requirements on the spectral purity of local oscillator sources.

就現有的頻率合成器設計下，分數式頻率合成器是一種廣泛地被使用的架構，其相較於其他頻率合成器的架構可具有較佳的雜訊表現。然而，無可避免地，分數式頻率合成器仍然會受到鎖相迴路之相位雜訊與量化雜訊的影響而造成輸出的振盪訊號不穩定，從而造成訊號調變的品質受到影響。因此，在高頻電路的應用下，如何降低本地振盪訊號的雜訊對訊號調變所造成的影響是訊號調變電路設計的重要課題。 Under the existing frequency synthesizer design, the fractional frequency synthesizer is a kind A widely used architecture that has better noise performance than other frequency synthesizer architectures. However, inevitably, the fractional frequency synthesizer is still affected by the phase noise and quantization noise of the phase-locked loop, causing the output oscillation signal to be unstable, thereby affecting the quality of the signal modulation. Therefore, in the application of high-frequency circuits, how to reduce the influence of the noise of the local oscillation signal on the signal modulation is an important issue in the design of the signal modulation circuit.

本發明提供一種訊號調變方法及應用其之訊號調變電路與收發機，其可有效地降低頻率合成器的量化雜訊對訊號調變所造成的影響。 The invention provides a signal modulation method and a signal modulation circuit and a transceiver thereof, which can effectively reduce the influence of quantization noise of a frequency synthesizer on signal modulation.

本發明的具量化雜訊抑制的訊號調變方法包括以下步驟：提供頻率合成器，以依據參考頻率訊號產生振盪訊號，並且依據經量化處理所獲得的除頻控制訊號對振盪訊號進行除頻，藉以產生除頻訊號作為頻率合成器的回授訊號；藉頻率合成器產生量化誤差訊號，其中量化誤差訊號指示量化處理所造成的量化雜訊大小；提供基頻處理單元，以接收輸入訊號與量化誤差訊號，並且對輸入訊號與量化誤差訊號進行預失真(Pre-distortion)處理，藉以產生一組正交的預失真訊號；以及提供調變單元，以接收預失真訊號與振盪訊號，並且依據振盪訊號對預失真訊號進行調變，從而產生輸出訊號。 The signal modulation method with quantization noise suppression of the present invention includes the following steps: providing a frequency synthesizer for generating an oscillation signal according to a reference frequency signal, and frequency-dividing the oscillation signal according to the frequency-divided control signal obtained by the quantization process, The frequency signal is generated as a feedback signal of the frequency synthesizer; the frequency synthesizer generates a quantization error signal, wherein the quantization error signal indicates the quantization noise caused by the quantization process; and the base frequency processing unit is provided to receive the input signal and quantize Error signal, And performing pre-distortion processing on the input signal and the quantization error signal to generate a set of orthogonal predistortion signals; and providing a modulation unit to receive the predistortion signal and the oscillation signal, and according to the oscillation signal The distortion signal is modulated to produce an output signal.

本發明的訊號調變電路包括頻率合成器、基頻訊號處理單元以及調變單元。頻率合成器依據參考頻率訊號產生振盪訊號，並且依據經量化處理所獲得的除頻控制訊號對振盪訊號進行除頻，藉以產生除頻訊號作為頻率合成器的回授訊號，其中頻率合成器更產生指示量化處理所造成的量化雜訊大小的量化誤差訊號。基頻處理單元耦接頻率合成器，用以接收輸入訊號，並且對基頻訊號與量化誤差訊號進行預失真處理，藉以產生一組正交的預失真訊號。調變單元耦接頻率合成器與基頻處理單元，用以接收預失真訊號與振盪訊號，並且依據振盪訊號對預失真訊號進行調變，從而產生輸出訊號。 The signal modulation circuit of the present invention comprises a frequency synthesizer, a baseband signal processing unit and a modulation unit. The frequency synthesizer generates an oscillation signal according to the reference frequency signal, and divides the oscillation signal according to the frequency-divided control signal obtained by the quantization process, thereby generating a frequency-divided signal as a feedback signal of the frequency synthesizer, wherein the frequency synthesizer generates A quantization error signal indicating the quantization noise size caused by the quantization process. The baseband processing unit is coupled to the frequency synthesizer for receiving the input signal, and predistorting the baseband signal and the quantization error signal to generate a set of orthogonal predistortion signals. The modulation unit is coupled to the frequency synthesizer and the baseband processing unit for receiving the predistortion signal and the oscillation signal, and modulating the predistortion signal according to the oscillation signal to generate an output signal.

本發明的無線通訊系統的收發機包括訊號調變電路以及射頻電路。訊號調變電路包括頻率合成器、基頻訊號處理單元以及調變單元。頻率合成器依據參考頻率訊號產生振盪訊號，並且依據經量化處理所獲得的除頻控制訊號對振盪訊號進行除頻，藉以產生除頻訊號作為頻率合成器的回授訊號，其中頻率合成器更產生指示量化處理所造成的量化雜訊大小的量化誤差訊號。基頻處理單元耦接頻率合成器，用以接收輸入訊號，並且對基頻訊號與量化誤差訊號進行預失真處理，藉以產生一組正交的預失真訊號。調變單元耦接頻率合成器與基頻處理單元，用以接收預失真訊號與振盪訊號，並且依據振盪訊號對預失真訊號進行調變，從而產生輸出訊號。射頻電路耦接訊號調變電路以接收輸出訊號，並且用以基於輸出訊號進行射頻訊號處理。 The transceiver of the wireless communication system of the present invention comprises a signal modulation circuit and a radio frequency circuit. The signal modulation circuit includes a frequency synthesizer, a baseband signal processing unit, and a modulation unit. The frequency synthesizer generates an oscillation signal according to the reference frequency signal, and divides the oscillation signal according to the frequency-divided control signal obtained by the quantization process, thereby generating a frequency-divided signal as a feedback signal of the frequency synthesizer, wherein the frequency synthesizer generates A quantization error signal indicating the quantization noise size caused by the quantization process. The baseband processing unit is coupled to the frequency synthesizer for receiving the input signal, and predistorting the baseband signal and the quantization error signal to generate a set of orthogonal predistortion signals. number. The modulation unit is coupled to the frequency synthesizer and the baseband processing unit for receiving the predistortion signal and the oscillation signal, and modulating the predistortion signal according to the oscillation signal to generate an output signal. The RF circuit is coupled to the signal modulation circuit to receive the output signal, and is used for RF signal processing based on the output signal.

基於上述，本發明實施例提出一種訊號調變方法及應用其之訊號調變電路與收發機。所述訊號調變方法可藉由預失真技術將指示頻率合成器之量化雜訊的量化誤差訊號混合至輸入訊號，使得調變器在進行訊號調變時，令經預失真的輸入訊號的量化雜訊成分與本地振盪源的量化雜訊成分相互抵銷，從而抑制了輸出訊號的量化雜訊而提高了輸出訊號的品質。另一方面，由於所述預失真的技術可藉由軟體及演算法的方式實現於基頻處理單元中，因此對整體訊號調變電路(特別是頻率合成器)而言，不需增設任何額外的硬體即可實現抑制量化雜訊的功效。 Based on the above, the embodiment of the present invention provides a signal modulation method and application thereof. Its signal modulation circuit and transceiver. The signal modulation method can mix the quantization error signal of the quantized noise indicating the frequency synthesizer to the input signal by using a predistortion technique, so that the modulator quantizes the predistorted input signal when performing signal modulation. The noise component and the quantized noise component of the local oscillator source cancel each other, thereby suppressing the quantization noise of the output signal and improving the quality of the output signal. On the other hand, since the pre-distortion technique can be implemented in the baseband processing unit by means of software and algorithms, there is no need to add any adjustment to the overall signal modulation circuit (especially the frequency synthesizer). Additional hardware can be used to suppress the effects of quantizing noise.

為讓本發明的上述特徵和優點能更明顯易懂，下文特舉實施例，並配合所附圖式作詳細說明如下。 The above described features and advantages of the invention will be apparent from the following description.

10‧‧‧無線通訊系統的收發機 10‧‧‧Transceivers for wireless communication systems

100、300‧‧‧訊號調變電路 100, 300‧‧‧ signal modulation circuit

110、310‧‧‧頻率合成器 110, 310‧‧‧ frequency synthesizer

120、320‧‧‧基頻處理單元 120, 320‧‧‧ fundamental frequency processing unit

130、330‧‧‧調變單元 130, 330‧‧ ‧ modulating unit

312‧‧‧鎖相迴路 312‧‧‧ phase-locked loop

314‧‧‧量化器 314‧‧‧Quantifier

322‧‧‧亂數產生器 322‧‧‧ random number generator

324‧‧‧基頻濾波器 324‧‧‧ fundamental frequency filter

326‧‧‧數位預失真器 326‧‧‧Digital predistorter

332‧‧‧相移器 332‧‧‧ phase shifter

334、336‧‧‧混頻器 334, 336‧‧‧ Mixer

338‧‧‧加法器 338‧‧‧Adder

ANT‧‧‧天線 ANT‧‧‧Antenna

BS‧‧‧基頻訊號 BS‧‧‧ fundamental frequency signal

I_PD、I_PD’、I_PD(t)、I_PD’(t)‧‧‧同相位預失真訊號 I _PD , I _PD ', I _PD (t), I _PD '(t)‧‧‧ phase predistortion signal

Ii、I、I(t)‧‧‧同相位輸入訊號 Ii, I, I(t)‧‧‧phase input signal

LPF‧‧‧迴路濾波器 LPF‧‧‧ loop filter

PFD‧‧‧相位頻率偵測器 PFD‧‧‧ phase frequency detector

Qi、Q、Q(t)‧‧‧正交相位輸出訊號 Qi, Q, Q(t)‧‧‧ Orthogonal phase output signals

Q_PD、Q_PD’、Q_PD(t)、Q_PD’(t)‧‧‧正交相位預失真訊號 Q _PD , Q _PD ', Q _PD (t), Q _PD '(t)‧‧‧Orthogonal phase predistortion signal

REF_CLK‧‧‧參考頻率訊號 REF_CLK‧‧‧ reference frequency signal

RFC‧‧‧射頻電路 RFC‧‧‧RF circuit

S210~S240‧‧‧步驟 S210~S240‧‧‧Steps

Sdiv‧‧‧除頻訊號 Sdiv‧‧‧frequency signal

Sdivc‧‧‧除頻控制訊號 Sdivc‧‧‧frequency control signal

SS‧‧‧弦波訊號 SS‧‧Sine wave signal

S_OSC、S_OSCQ、S_OSC(t)、S_OSCQ(t)‧‧‧振盪訊號 S _OSC , S _OSCQ , S _OSC (t), S _OSCQ (t) _{‧ ‧} oscillating signal

S_PD‧‧‧預失真訊號 S _PD ‧‧‧Predistorted signal

S_CTL‧‧‧控制訊號 S _CTL ‧‧‧ control signal

Sin‧‧‧輸入訊號 Sin‧‧‧ input signal

Sout、Sout(t)‧‧‧輸出訊號 Sout, Sout(t)‧‧‧ output signals

SW1‧‧‧開關 SW1‧‧‧ switch

VCO‧‧‧壓控振盪器 VCO‧‧‧voltage controlled oscillator

ψ_n,DSM、ψ_n,DSM(t)‧‧‧量化誤差訊號 ψ _{n, DSM} , ψ _{n, DSM} (t) ‧ ‧ Quantification error signal

ψ_n,PLL、ψ_n,PLL(t)‧‧‧相位雜訊 ψ _{n, PLL} , ψ _{n, PLL} (t) ‧ ‧ phase noise

圖1為本發明一實施例的無線通訊系統的收發機的功能方塊示意圖。 1 is a functional block diagram of a transceiver of a wireless communication system according to an embodiment of the present invention.

圖2為依照圖1之一實施例的訊號調變方法的步驟流程圖。 2 is a flow chart showing the steps of a signal modulation method according to an embodiment of FIG. 1.

圖3為本發明一實施例的訊號調變電路的架構示意圖。 FIG. 3 is a schematic structural diagram of a signal modulation circuit according to an embodiment of the present invention.

圖4為依照圖3之一實施例的系統雜訊分析示意圖。 4 is a schematic diagram of system noise analysis in accordance with an embodiment of FIG.

為了使本揭露之內容可以被更容易明瞭，以下特舉實施例做為本揭露確實能夠據以實施的範例。另外，凡可能之處，在圖式及實施方式中使用相同標號的元件/構件/步驟，係代表相同或類似部件。 In order to make the disclosure of the present disclosure easier to understand, the following specific embodiments are examples of the disclosure that can be implemented. In addition, wherever possible, the same elements, components, and steps in the drawings and embodiments are used to represent the same or similar components.

圖1為本發明一實施例的無線通訊系統的收發機(transceiver)的功能方塊示意圖。請參照圖1，本實施例的收發機100可應用於無線通訊系統的傳送端(TX)及/或接收端(RX)。收發機10包括訊號調變電路100以及射頻電路RFC。其中，訊號調變電路100包括頻率合成器110、基頻處理單元120以及調變單元130。 1 is a functional block diagram of a transceiver of a wireless communication system according to an embodiment of the present invention. Referring to FIG. 1, the transceiver 100 of the present embodiment can be applied to a transmitting end (TX) and/or a receiving end (RX) of a wireless communication system. The transceiver 10 includes a signal modulation circuit 100 and a radio frequency circuit RFC. The signal modulation circuit 100 includes a frequency synthesizer 110, a baseband processing unit 120, and a modulation unit 130.

在本實施例中，頻率合成器110例如為分數式頻率合成器，其可利用回授控制的方式而依據參考頻率訊號REF_CLK提供具有特定頻率與相位的振盪訊號Sosc。基頻處理單元120會根據所接收的輸入訊號Sin而進行訊號處理，藉以產生相互正交的相位訊號(如I_PD與Q_PD)。調變單元130則會基於頻率合成器110所產生的振盪訊號S_OSC來對從基頻處理單元120所接收到的相位訊號進行調變，藉以產生輸出訊號Sout給後級的電路。 In this embodiment, the frequency synthesizer 110 is, for example, a fractional frequency synthesizer, which can provide an oscillation signal Sosc having a specific frequency and phase according to the reference frequency signal REF_CLK by means of feedback control. The baseband processing unit 120 performs signal processing according to the received input signal Sin to generate mutually orthogonal phase signals (such as I _PD and Q _PD ). The modulation unit 130 modulates the phase signal received from the baseband processing unit 120 based on the oscillation signal S _OSC generated by the frequency synthesizer 110, thereby generating an output signal Sout to the circuit of the subsequent stage.

更具體地說，在所述收發機100應用於傳送端時，收發機100可視為無線通訊系統的發射機(transmitter)，其所接收的輸入訊號Sin為前端的訊號處理電路(未繪示)所傳送的基頻訊號(baseband signal)，而其所發射的輸出訊號Sout則為經調變與疊加後的調變訊號。所述射頻電路RFC於此可例如為射頻發射電路，其可進一步對輸出訊號Sout(調變訊號)進行濾波、低雜訊放大、升頻及功率放大等訊號處理動作，以將輸出訊號Sout轉換為射頻訊號，再藉由天線ANT將射頻訊號發射。 More specifically, when the transceiver 100 is applied to a transmitting end, the transceiver 100 can be regarded as a transmitter of the wireless communication system, which receives the transmitter The input signal Sin is a baseband signal transmitted by a signal processing circuit (not shown) of the front end, and the output signal Sout transmitted by the input signal is a modulated and superimposed modulated signal. The RF circuit RFC can be, for example, a radio frequency transmitting circuit, which can further filter the output signal Sout (modulation signal), low noise amplification, up-conversion and power amplification to convert the output signal Sout. For the RF signal, the RF signal is transmitted by the antenna ANT.

另一方面，在所述收發機100應用於接收端時，收發機 100可視為無線通訊系統的接收機(receiver)，其所接收的輸入訊號Sin為一預設的弦波訊號，而其所發射的輸出訊號Sout則為經調變與疊加後的載波訊號。所述射頻電路RFC於此可例如為設頻接收電路，其可從天線ANT接收射頻訊號，並且對接收到的射頻訊號進行濾波、低雜訊放大及降頻等訊號處理動作，以將接收到的射頻訊號轉換為基頻訊號，再利用調變單元130所產生的輸出訊號Sout(載波訊號)來對降頻後的訊號進行解調變。 On the other hand, when the transceiver 100 is applied to the receiving end, the transceiver The receiver 100 can be regarded as a receiver of the wireless communication system, and the received input signal Sin is a preset sine wave signal, and the output signal Sout transmitted by the receiver is a modulated and superimposed carrier signal. The RF circuit RFC can be, for example, a frequency receiving circuit that can receive an RF signal from the antenna ANT, and performs filtering, low noise amplification, and frequency reduction on the received RF signal to receive the signal. The RF signal is converted into a baseband signal, and the output signal Sout (carrier signal) generated by the modulation unit 130 is used to demodulate the down-converted signal.

底下以圖2實施例來說明本發明實施例的訊號調變電路及其訊號調變方法。其中，圖2為依照圖1之一實施例的訊號調變方法的步驟流程圖。 The signal modulation circuit of the embodiment of the present invention is described below with reference to the embodiment of FIG. And its signal modulation method. 2 is a flow chart of the steps of the signal modulation method according to an embodiment of FIG. 1.

請同時參照圖1與圖2，在本實施例的訊號調變方法中，首先，提供頻率合成器110，以依據參考頻率訊號REF_CLK產生振盪訊號S_OSC，並且依據經量化處理(quantization process)所獲得的除頻控制訊號對振盪訊號S_OSC進行除頻，藉以產生除頻訊號作為頻率合成器110的回授訊號(步驟S210)。接著，藉頻率合成器110產生量化誤差訊號ψ_n,DSM，其中量化誤差訊號指示量化處理所造成的量化雜訊大小(步驟S220)。在上述步驟中，所述量化處理可由頻率合成器110中的量化器(於此未繪示，後續實施例會進一步說明)依據回授給頻率合成器110之輸入端的除頻訊號所進行。 Referring to FIG. 1 and FIG. 2 simultaneously, in the signal modulation method of the embodiment, first, the frequency synthesizer 110 is provided to generate the oscillation signal S _OSC according to the reference frequency signal REF_CLK, and according to the quantization process. The obtained frequency division control signal divides the oscillation signal S _OSC to generate a frequency-divided signal as a feedback signal of the frequency synthesizer 110 (step S210). Next, the quantization error signal ψ _{n, DSM is} generated by the frequency synthesizer 110, wherein the quantization error signal indicates the quantization noise size caused by the quantization process (step S220). In the above steps, the quantization process may be performed by a quantizer in the frequency synthesizer 110 (not shown here, which will be further explained in the following embodiments) according to the demultiplexed signal fed back to the input of the frequency synthesizer 110.

其後，提供基頻處理單元120，以接收輸入訊號Sin與頻率合成器110所產生的量化誤差訊號ψ_n,DSM，並且對輸入訊號Sin與量化誤差訊號ψ_n,DSM進行預失真(Pre-distortion)處理，藉以產生一組正交的預失真訊號S_PD(包括同相位(in phase)預失真訊號I_PD與正交相位(quadrature-phase)預失真訊號Q_PD)(步驟S230)。 Thereafter, the baseband processing unit 120 is provided to receive the quantization error signals ψ _{n, DSM} generated by the input signal Sin and the frequency synthesizer 110, and pre-distort the input signal Sin and the quantization error signals ψ _{n, DSM} (Pre- Distortion processing to generate a set of orthogonal predistortion signals S _PD (including an in phase predistortion signal I _PD and a quadrature-phase predistortion signal Q _PD ) (step S230).

在基頻處理單元120產生預失真訊號S_PD後，提供調變單元130，以接收預失真訊號S_PD與振盪訊號S_OSC，並且依據振盪訊號S_OSC對預失真訊號S_PD進行調變，從而產生輸出訊號Sout(步驟S240)。 After the pre-distortion signal S _{PD is} generated by the baseband processing unit 120, the modulation unit 130 is configured to receive the pre-distortion signal S _PD and the oscillation signal S _OSC , and modulate the pre-distortion signal S _PD according to the oscillation signal S _OSC , thereby The output signal Sout is generated (step S240).

根據上述步驟流程，藉由將量化誤差訊號ψ_n,DSM混合至輸入訊號Sin的預失真技術，頻率合成器100在量化處理時所產生的量化雜訊可在調變單元130進行預失真訊號S_PD與振盪訊號S_OSC的調變時相互抵消，從而抑制了輸出訊號Sout的量化雜訊。 According to the above-mentioned step flow, by using the quantization error signal ψ _{n, the DSM is} mixed into the pre-distortion technique of the input signal Sin, the quantization noise generated by the frequency synthesizer 100 during the quantization process can be pre-distorted signal S in the modulation unit 130. The modulation of the _PD and the oscillation signal S _OSC cancel each other out, thereby suppressing the quantization noise of the output signal Sout.

此外，由於上述在基頻處理單元120中進行預失真的演算動作可藉由軟體/演算法的方式來實現，因此就硬體架構而言，本發明實施例的訊號調變電路100可在不需增加額外硬體電路的前提(特別是不需更動頻率合成器110的硬體設計)下實現量化雜訊的抑制，從而提高調變的品質。 In addition, since the above-mentioned calculation of the pre-distortion in the baseband processing unit 120 can be implemented by a software/algorithm, the signal modulation circuit 100 of the embodiment of the present invention can be No need to add extra hardware circuits The premise (especially without changing the hardware design of the frequency synthesizer 110) achieves suppression of quantization noise, thereby improving the quality of modulation.

為了更清楚的說明上述訊號調變電路100的實施範例與運作，底下以圖3實施例作進一步說明。其中，圖3為本發明一實施例的訊號調變電路的架構示意圖。 In order to more clearly illustrate the implementation and operation of the above-described signal modulation circuit 100, the embodiment of FIG. 3 is further described below. FIG. 3 is a schematic structural diagram of a signal modulation circuit according to an embodiment of the present invention.

請參照圖3，在本實施例的訊號調變電路300中，其包括頻率合成器310、基頻處理單元320以及調變單元330。於此，所述頻率合成器310例如為分數式頻率合成器(fractional-N frequency synthesizer)，所述基頻處理單元320可例如以中央處理單元(CPU)及/或微控制器(MCU)來實現，而所述調變單元330例如為正交調變器(quadrature modulator)，但本發明不僅限於此。 Referring to FIG. 3, in the signal modulation circuit 300 of this embodiment, the frequency synthesizer 310, the baseband processing unit 320, and the modulation unit 330 are included. Here, the frequency synthesizer 310 is, for example, a fractional-N frequency synthesizer, and the baseband processing unit 320 can be, for example, a central processing unit (CPU) and/or a microcontroller (MCU). This is achieved, and the modulation unit 330 is, for example, a quadrature modulator, but the invention is not limited thereto.

詳細而言，在頻率合成器310中，其包括鎖相迴路(phase lock loop，PLL)312以及量化器314。鎖相迴路312會接收參考頻率訊號REF_CLK、除頻訊號Sdiv以及除頻控制訊號Sdivc，並據以產生振盪訊號S_OSC。量化器314會接收除頻訊號Sdiv以進行量化處理而產生除頻控制訊號來控制鎖相迴路312的除頻操作。此外，量化器314會根據量化處理所造成的量化雜訊大小而產生對應的量化誤差訊號ψ_n,DSM給基頻處理單元320。 In detail, in the frequency synthesizer 310, it includes a phase lock loop (PLL) 312 and a quantizer 314. The phase-locked loop 312 receives the reference frequency signal REF_CLK, the frequency-divided signal Sdiv, and the frequency-dividing control signal Sdivc, and generates an oscillation signal S _{OSC accordingly} . The quantizer 314 receives the frequency-divided signal Sdiv for quantization processing to generate a frequency-dividing control signal to control the frequency-dividing operation of the phase-locked loop 312. In addition, the quantizer 314 generates a corresponding quantization error signal ψ _{n, DSM,} to the baseband processing unit 320 according to the quantization noise caused by the quantization process.

底下具體說明鎖相迴路312的架構與運作。鎖相迴路312可例如包括相位頻率偵測器PFD、迴路濾波器LPF、壓控振盪器VCO以及多模數除頻器(multi-modulus frequency divider)MMD。 The architecture and operation of the phase locked loop 312 are specifically illustrated below. The phase locked loop 312 can include, for example, a phase frequency detector PFD, a loop filter LPF, a voltage controlled oscillator VCO, and a multi-modulus frequency divider MMD.

相位頻率偵測器PFD會接收參考頻率訊號REF_CLK與除頻訊號Sdiv，並且依據參考頻率訊號REF_CLK與除頻訊號Sdiv產生相位差訊號S_PD。更具體地說，當相位頻率偵測器PFD接收到參考頻率訊號REF_CLK與除頻訊號Sdiv時，相位頻率偵測器PFD將會比較參考頻率訊號REF_CLK與除頻訊號Sdiv的頻率相位，並依據參考頻率訊號REF_CLK與除頻訊號Sdiv之間的相位差來產生相位差訊號S_PD。 The phase frequency detector PFD receives the reference frequency signal REF_CLK and the frequency-divided signal Sdiv, and generates a phase difference signal S _PD according to the reference frequency signal REF_CLK and the frequency-divided signal Sdiv. More specifically, when the phase frequency detector PFD receives the reference frequency signal REF_CLK and the frequency-divided signal Sdiv, the phase frequency detector PFD compares the frequency phase of the reference frequency signal REF_CLK and the frequency-divided signal Sdiv, and according to the reference. The phase difference between the frequency signal REF_CLK and the frequency division signal Sdiv generates a phase difference signal S _PD .

迴路濾波器LPF耦接相位頻率偵測器PFD以接收相位差訊號S_PD，並依據相位差訊號S_PD產生控制訊號S_CTL。其中，迴路濾波器LPF可例如為一種低通濾波器，其可用以濾除相位差訊號S_PD中的雜訊，藉以產生訊號品質較佳的控制訊號S_CTL。 The loop filter LPF is coupled to the phase frequency detector PFD to receive the phase difference signal S _PD and generate the control signal S _CTL according to the phase difference signal S _PD . The loop filter LPF can be, for example, a low-pass filter, which can be used to filter out the noise in the phase difference signal S _PD , thereby generating a control signal S _{CTL with} better signal quality.

壓控振盪器VCO耦接迴路濾波器LPF以接收迴路濾波器LPF所產生的控制訊號S_CTL，並依據控制訊號S_CTL產生振盪訊號S_OSC。其中，振盪訊號S_OSC的振盪頻率會隨著控制訊號S_CTL而改變。 The voltage controlled oscillator VCO is coupled to the loop filter LPF to receive the control signal S _CTL generated by the loop filter LPF, and generates an oscillation signal S _OSC according to the control signal S _CTL . The oscillation frequency of the oscillation signal S _OSC changes with the control signal S _CTL .

多模數除頻器(multi-modulus frequency divider)MMD耦接相位頻率偵測器PFD、壓控振盪器VCO以及量化器314。多模數除頻器MMD會受控於除頻控制訊號Sdivc而選擇多個不同的除頻值來對振盪訊號S_OSC進行除頻，藉以產生除頻訊號Sdiv。其中，所述除頻值可為分數除頻值。 The multi-modulus frequency divider MMD is coupled to a phase frequency detector PFD, a voltage controlled oscillator VCO, and a quantizer 314. The multi-modulus frequency divider MMD is controlled by the frequency-dividing control signal Sdivc to select a plurality of different frequency-divided values to divide the oscillation signal S _OSC to generate the frequency-divided signal Sdiv. Wherein, the frequency division value may be a fractional frequency division value.

除此之外，在一範例實施例中，鎖相迴路312還可包括一電荷幫浦(未繪示)。所述電荷幫浦可設置於相位頻率偵測器211與迴路濾波器之間，藉以接收相位差訊號S_PD，並依據相位差訊號 S_PD產生相對應的充電訊號。而所述充電訊號經迴路濾波器LPF濾波可作為控制壓控制盪器VCO的依據。 In addition, in an exemplary embodiment, the phase locked loop 312 may further include a charge pump (not shown). The charge pump can be disposed between the phase frequency detector 211 and the loop filter to receive the phase difference signal S _PD and generate a corresponding charging signal according to the phase difference signal S _PD . The charging signal is filtered by the loop filter LPF as a basis for controlling the voltage control VCO.

另一方面，本實施例的量化器314可用以受控於一通道選擇器(channel selector，未繪示)而對多模數除頻器MMD的除頻值進行量化處理，並依據此量化處理的結果來產生除頻控制訊號Sdivc。其中，所述量化器314可利用差異積分調變器(delta-sigma modulator)來實現(但不僅限於此)。所述差異積分調變器可將量化雜訊隨機化，藉以避免分數突波(fractional spur)的產生。此外，差異積分調變器可藉由雜訊整形(noise-shaping)以及超取樣(over-sampling)的技術將量化雜訊推往較高之頻率，使其容易被迴路濾波器LPF之低通濾波特性所濾除。 On the other hand, the quantizer 314 of the present embodiment can be used to be controlled by one channel. A frequency selector (not shown) quantizes the frequency division value of the multi-modulus frequency divider MMD, and generates a frequency division control signal Sdivc according to the result of the quantization processing. Wherein, the quantizer 314 can implement (but is not limited to) by using a delta-sigma modulator. The difference integral modulator can randomize the quantization noise to avoid the generation of fractional spur. In addition, the difference integral modulator can push the quantization noise to a higher frequency by noise-shaping and over-sampling techniques, making it easy to be low-passed by the loop filter LPF. Filter characteristics are filtered out.

在基頻處理單元320中，其包括亂數產生器322、基頻濾波器324以及數位預失真器(digital predistorter)326。亂數產生器322可用以依據輸入訊號Sin產生同相位輸入訊號Ii與正交相位輸入訊號Qi。基頻濾波器324會接收亂數產生器322所輸出的同相位輸入訊號Ii與正交相位輸入訊號Qi，並且分別對兩者進行濾波處理，藉以產生經濾波處理後的同相位輸入訊號I與正交相位輸入訊號Q。數位預失真器326則會接收經濾波處理後的同相位輸入訊號I與正交相位輸入訊號Q以及量化器314所輸出的量化誤差訊號ψ_n,DSM。其中，數位預失真器326會基於座標旋轉數位電腦(coordinated rotation digital computer，CORDIC)演算法，以量化誤差訊號ψ_n,DSM對所接收的同相位輸入訊號I與正交相位輸入訊號Q進行相位轉換，藉以產生帶有量化雜訊成分的預失真訊號S_PD。 In the baseband processing unit 320, it includes a random number generator 322, a baseband filter 324, and a digital predistorter 326. The random number generator 322 can be configured to generate the in-phase input signal Ii and the quadrature phase input signal Qi according to the input signal Sin. The baseband filter 324 receives the in-phase input signal Ii and the quadrature phase input signal Qi output by the random number generator 322, and separately filters the two to generate the filtered in-phase input signal I and Quadrature phase input signal Q. The digital predistorter 326 receives the filtered in-phase input signal I and the quadrature phase input signal Q and the quantized error signals ψ _{n, DSM} output by the quantizer 314. The digital predistorter 326 is based on a coordinated rotation digital computer (CORDIC) algorithm to quantize the error signal ψ _{n, and the DSM} phase the received in-phase input signal I and the quadrature phase input signal Q. Converting to generate a predistortion signal S _PD with quantized noise components.

在調變單元330中，其包括相移器(phase shifter，於此標示“90°”以指示其係進行正交相移)332、混頻器(mixer)334與336以及加法器(adder)338。其中，相移器332會將所接收到的振盪訊號S_OSC進行正交相移，藉以產生與振盪訊號S_OSC正交的振盪訊號S_OSCQ。混頻器334與336會分別以振盪訊號S_OSC與S_OSCQ作為本地振盪源，各自和對應的預失真訊號I_PD與Q_PD進行混頻，從而產生混頻後的預失真訊號I_PD’與Q_PD’。混頻後的預失真訊號I_PD’與Q_PD’會透過加法器338進行訊號疊加，從而產生輸出訊號Sout。 In the modulation unit 330, it includes a phase shifter (herein labeled "90°" to indicate that it is performing quadrature phase shift) 332, mixers 334 and 336, and an adder. 338. Wherein the phase shifter 332 will be received by the oscillation signal S _OSC quadrature phase shift so as to generate the oscillation signal and the oscillation signal S _OSC _S OSCQ orthogonal. The mixers 334 and 336 respectively use the oscillation signals S _OSC and S _OSCQ as local oscillation sources, and respectively mix with the corresponding predistortion signals I _PD and Q _PD to generate the mixed predistortion signals I _PD 'and Q _PD '. The mixed predistortion signals I _PD 'and Q _PD ' are signal superimposed by the adder 338 to generate an output signal Sout.

其中，藉由調變單元330的混頻與訊號疊加處理，預失真訊號S_PD中的量化雜訊成分會與振盪訊號S_OSC與S_OSCQ的量化雜訊成分相互抵銷，從而使得輸出訊號Sout具有低量化雜訊的特性。 The quantization noise component in the predistortion signal S _PD is offset from the quantization noise components of the oscillation signals S _OSC and S _OSCQ by the mixing and signal superposition processing of the modulation unit 330, so that the output signal Sout is output. Features low quantization noise.

另外值得一提的是，在一範例實施例中，訊號調變電路300還可包括有開關SW1。在訊號調變電路300所應用之收發機(如100)係設置於傳送端時，開關SW1可切換為將基頻訊號BS提供至亂數產生器322的開關組態。此時訊號調變電路300所輸出的輸出訊號Sout為傳送端的調變訊號。相反地，在訊號調變電路300所應用之收發機係設置於接收端時，開關SW1可切換為將弦波訊號SS提供至亂數產生器322的開關組態。此時訊號調變電路300所輸出的輸出訊號Sout為接收端用於解調變的載波訊號。 It is also worth mentioning that, in an exemplary embodiment, the signal modulation circuit 300 may further include a switch SW1. When the transceiver (eg, 100) to which the signal modulation circuit 300 is applied is disposed at the transmitting end, the switch SW1 can be switched to a switch configuration that supplies the baseband signal BS to the random number generator 322. At this time, the output signal Sout outputted by the signal modulation circuit 300 is a modulation signal of the transmitting end. Conversely, when the transceiver to which the signal modulation circuit 300 is applied is disposed at the receiving end, the switch SW1 can be switched to a switch configuration that provides the sine wave signal SS to the random number generator 322. At this time, the output signal Sout outputted by the signal modulation circuit 300 is a carrier signal used by the receiving end to demodulate the variable.

為了更清楚的說明本發明實施例的訊號調變電路的量化雜訊抑制的機制，底下以圖4作進一步的說明。其中，圖4為依照圖3之一實施例的系統雜訊分析示意圖。 In order to more clearly illustrate the mechanism of quantization noise suppression of the signal modulation circuit of the embodiment of the present invention, FIG. 4 is further described below. 4 is a schematic diagram of system noise analysis according to an embodiment of FIG. 3.

請同時參照圖3與圖4，於此，同相位輸入訊號I(t)與正交相位輸入訊號Q(t)為經亂數及濾波處理後的輸入訊號Sin。在本實施例中，同相位輸入訊號I(t)與正交相位輸入訊號Q(t)會先在基頻處理單元320中依據量化誤差訊號ψ_n,DSM以CORDIC演算法進行相位轉換，藉以產生同相位預失真訊號I_PD(t)與正交相位預失真訊號Q_PD(t)。其中，經CORDIC演算法所產生的預失真訊號I_PD(t)與Q_PD(t)可以下式表示： Please refer to FIG. 3 and FIG. 4 at the same time. Here, the in-phase input signal I(t) and the quadrature phase input signal Q(t) are the random number and filtering input signal Sin. In this embodiment, the in-phase input signal I(t) and the quadrature-phase input signal Q(t) are first phase-converted in the baseband processing unit 320 according to the quantization error signal ψ _{n, and the DSM} performs the CORDIC algorithm. The in-phase predistortion signal I _PD (t) and the quadrature phase predistortion signal Q _PD (t) are generated. Among them, the predistortion signals I _PD (t) and Q _PD (t) generated by the CORDIC algorithm can be expressed as follows:

另一方面，由頻率合成器310所產生的振盪訊號S_OSC與S_OSCQ可以下式表示： On the other hand, the oscillation signals S _OSC and S _OSCQ generated by the frequency synthesizer 310 can be expressed as follows:

其中，ψ_n,PLL為頻率合成器310中的鎖相迴路312所造成的相位雜訊。 Where ψ _{n, the PLL} is phase noise caused by the phase locked loop 312 in the frequency synthesizer 310.

當調變電路330對預失真訊號I_PD(t)與Q_PD(t)進行調變時，同相位預失真訊號I_PD(t)會與振盪訊號S_OSC進行混頻，而正交相位預失真訊號Q_PD(t)則會與振盪訊號S_OSCQ進行混頻。故經混頻後的同相位預失真訊號I_PD’(t)與正交相位預失真訊號Q_PD’(t)可以下式表示： When the modulation circuit 330 modulates the predistortion signals I _PD (t) and Q _PD (t), the in-phase predistortion signal I _PD (t) is mixed with the oscillation signal S _OSC , and the quadrature phase The predistortion signal Q _PD (t) is mixed with the oscillation signal S _OSCQ . Therefore, the mixed in-phase predistortion signal I _PD '(t) and the quadrature phase predistortion signal Q _PD '(t) can be expressed as follows:

其後，混頻後的同相位預失真訊號I_PD’(t)與正交相位預失真訊號Q_PD’(t)會再進行疊加以產生輸出訊號Sout。故輸出訊號Sout可以下式表示： Thereafter, the mixed in-phase predistortion signal I _PD '(t) and the quadrature phase predistortion signal Q _PD '(t) are superimposed to generate an output signal Sout. Therefore, the output signal Sout can be expressed as follows:

藉由和差化積的運算，式(7)可進一步地化簡為以下式： Equation (7) can be further reduced to the following equation by the operation of the difference product:

由式(1)至式(8)的推導可知，在化簡後的輸出訊號Sout(t)中，其僅存有鎖相迴路312的相位雜訊ψ_n,PLL(t)成分，而量化誤差訊號ψ_n,DSM(t)的成分已經大致上被抵銷，因此可證明訊號調變電路Sout所產生的輸出訊號Sout的量化雜訊可藉由本發明實施例的預失真技術而被抵銷/抑制，從而提高訊號調變的品質。 From the derivation of equations (1) to (8), it can be seen that in the reduced output signal Sout(t), only the phase noise ψ _{n, PLL} (t) component of the phase-locked loop 312 is stored, and the quantization is performed. The components of the error signal ψ _{n, DSM} (t) have been substantially offset, so that the quantization noise of the output signal Sout generated by the signal modulation circuit Sout can be proved by the predistortion technique of the embodiment of the present invention. Pin/suppression, which improves the quality of signal modulation.

綜上所述，本發明實施例提出一種訊號調變方法及應用其之訊號調變電路與收發機。所述訊號調變方法可藉由預失真技術將指示頻率合成器之量化雜訊的量化誤差訊號混合至輸入訊號，使得調變器在進行訊號調變時，令經預失真的輸入訊號的量化雜訊成分與本地振盪源的量化雜訊成分相互抵銷，從而抑制了輸出訊號的量化雜訊而提高了輸出訊號的品質。另一方面，由於所述預失真的技術可藉由軟體及演算法的方式實現於基頻處理單元中，因此對整體訊號調變電路(特別是頻率合成器)而言，不需增設任何額外的硬體即可實現抑制量化雜訊的功效。 In summary, the embodiment of the present invention provides a signal modulation method and a signal modulation circuit and a transceiver thereof. The signal modulation method can mix the quantization error signal of the quantized noise indicating the frequency synthesizer to the input signal by using a predistortion technique, so that the modulator quantizes the predistorted input signal when performing signal modulation. The noise component and the quantized noise component of the local oscillator source cancel each other, thereby suppressing the quantization noise of the output signal and improving the quality of the output signal. On the other hand, since the predistortion technique can be implemented in a baseband processing method by means of software and algorithms In the yuan, therefore, for the overall signal modulation circuit (especially the frequency synthesizer), the effect of suppressing the quantization noise can be achieved without adding any additional hardware.

雖然本發明已以實施例揭露如上，然其並非用以限定本發明，任何所屬技術領域中具有通常知識者，在不脫離本發明的精神和範圍內，當可作些許的更動與潤飾，故本發明的保護範圍當視後附的申請專利範圍所界定者為準。 Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

S210~S240‧‧‧步驟 S210~S240‧‧‧Steps

Claims

一種具量化雜訊抑制的訊號調變方法，包括：提供一頻率合成器，以依據一參考頻率訊號產生一振盪訊號，並且依據經一量化處理所獲得的一除頻控制訊號對該振盪訊號進行除頻，藉以產生一除頻訊號作為該頻率合成器的回授訊號；藉該頻率合成器產生一量化誤差訊號，其中該量化誤差訊號指示該量化處理所造成的一量化雜訊大小；提供一基頻處理單元，以接收一輸入訊號與該量化誤差訊號，並且對該輸入訊號與該量化誤差訊號進行一預失真(Pre-distortion)處理，藉以產生一組正交的預失真訊號；以及提供一調變單元，以接收該組預失真訊號與該振盪訊號，並且依據該振盪訊號對該組預失真訊號進行調變，從而產生一輸出訊號。 A signal modulation method with quantization noise suppression includes: providing a frequency synthesizer for generating an oscillation signal according to a reference frequency signal, and performing the oscillation signal according to a frequency division control signal obtained by a quantization process The frequency division is used to generate a frequency-divided signal as a feedback signal of the frequency synthesizer; the frequency synthesizer generates a quantization error signal, wherein the quantization error signal indicates a quantization noise caused by the quantization process; The baseband processing unit receives an input signal and the quantization error signal, and performs a pre-distortion process on the input signal and the quantization error signal to generate a set of orthogonal predistortion signals; a modulation unit for receiving the set of pre-distortion signals and the oscillation signal, and modulating the group of pre-distortion signals according to the oscillation signal, thereby generating an output signal.

如申請專利範圍第1項所述的具量化雜訊抑制的訊號調變方法，其中藉該基頻處理單元進行該預失真處理的步驟包括：依據該輸入訊號產生一同相位(in-phase)輸入訊號與一正交相位(quadrature-phase)輸入訊號；以及基於座標旋轉數位電腦(coordinated rotation digital computer，CORDIC)演算法，以該量化誤差訊號對該同相位輸入訊號與該正交相位輸入訊號進行相位轉換，藉以產生該組預失真訊號。 The signal modulation method with quantization noise suppression according to claim 1, wherein the step of performing the predistortion processing by the baseband processing unit comprises: generating an in-phase input according to the input signal. a signal and a quadrature-phase input signal; and a coordinate rotation digital computer (CORDIC) algorithm, wherein the same phase input signal and the quadrature phase input signal are performed by the quantization error signal Phase conversion to generate the set of predistortion signals.

如申請專利範圍第2相所述的具量化雜訊抑制的訊號調變方法，其中該組預失真訊號包括一同相位預失真訊號與一正交相位預失真訊號，經CORDIC演算法所產生的預失真訊號係以下式表示：其中，I_PD(t)為該同相位預失真訊號，Q_PD(t)為該正交相位預失真訊號，I(t)為該同相位輸入訊號，Q(t)為該正交相位輸入訊號，以及ψ_n,DSM(t)為該量化誤差訊號。 The signal modulation method with quantization noise suppression according to the second phase of the patent application scope, wherein the pre-distortion signal comprises a phase predistortion signal and a quadrature phase predistortion signal, and the prediction generated by the CORDIC algorithm The distortion signal is expressed by the following formula: Where I _PD (t) is the in-phase predistortion signal, Q _PD (t) is the quadrature phase predistortion signal, I(t) is the inphase input signal, and Q(t) is the quadrature phase input The signal, and ψ _{n, DSM} (t) is the quantization error signal.

如申請專利範圍第1項所述的具量化雜訊抑制的訊號調變方法，其中該量化處理係該頻率合成器依據該除頻訊號所進行。 The signal modulation method with quantization noise suppression according to claim 1, wherein the quantization process is performed by the frequency synthesizer according to the frequency division signal.

一種訊號調變電路，包括：一頻率合成器，依據一參考頻率訊號產生一振盪訊號，並且依據經一量化處理所獲得的一除頻控制訊號對該振盪訊號進行除頻，藉以產生一除頻訊號作為該頻率合成器的回授訊號，其中該頻率合成器更產生指示該量化處理所造成的一量化雜訊大小的一量化誤差訊號；一基頻處理單元，耦接該頻率合成器，用以接收一輸入訊號，並且對該基頻訊號與該量化誤差訊號進行一預失真處理，藉以產生一組正交的預失真訊號；以及一調變單元，耦接該頻率合成器與該基頻處理單元，用以接收該組預失真訊號與該振盪訊號，並且依據該振盪訊號對該組預失真訊號進行調變，從而產生一輸出訊號。 A signal modulation circuit includes: a frequency synthesizer, generating an oscillation signal according to a reference frequency signal, and dividing the oscillation signal according to a frequency division control signal obtained by a quantization process, thereby generating a division The frequency signal is used as a feedback signal of the frequency synthesizer, wherein the frequency synthesizer further generates a quantization error signal indicating a quantization noise caused by the quantization process; a fundamental frequency processing unit coupled to the frequency synthesizer, Receiving an input signal, and performing a predistortion process on the fundamental frequency signal and the quantization error signal to generate a set of orthogonal predistortion signals; and a modulation unit coupled to the frequency synthesizer and the base The frequency processing unit is configured to receive the set of pre-distortion signals and the oscillating signal, and modulate the set of pre-distortion signals according to the oscillating signal to generate an output signal.

如申請專利範圍第5項所述的訊號調變電路，其中該頻率合成器包括：一鎖相迴路(phase lock loop，PLL)，接收該參考頻率訊號、該除頻訊號以及該除頻控制訊號，並據以產生該振盪訊號；以及一量化器(quantizer)，接收該除頻訊號以進行該量化處理以產生該除頻控制訊號給該鎖相迴路，並且產生該量化誤差訊號給該基頻處理單元。 The signal modulation circuit of claim 5, wherein the frequency synthesizer comprises: a phase lock loop (PLL), receiving the reference frequency signal, the frequency division signal, and the frequency division control And generating a oscillating signal; and a quantizer receiving the de-frequency signal to perform the quantization process to generate the frequency-dividing control signal to the phase-locked loop, and generating the quantization error signal to the base Frequency processing unit.

如申請專利範圍第6項所述的訊號調變電路，其中該頻率合成器為分數式頻率合成器(fractional-N frequency synthesizer)，且該鎖相迴路包括：一相位頻率偵測器，接收該參考訊號與該除頻訊號，依據該參考頻率訊號與該除頻訊號產生一相位差訊號；一迴路濾波器，耦接該相位頻率偵測器以接收該相位差訊號，並依據該相位差訊號產生一控制訊號；一壓控振盪器，耦接該迴路濾波器以接收該控制訊號，並依據該控制訊號產生該振盪訊號；以及一多模數除頻器(multi-modulus frequency divider)，耦接該相位頻率偵測器、該壓控振盪器以及該量化器，受控於該除頻控制訊號而對該振盪訊號進行除頻，藉以產生該除頻訊號。 The signal modulation circuit of claim 6, wherein the frequency synthesizer is a fractional-N frequency synthesizer, and the phase-locked loop comprises: a phase frequency detector, receiving The reference signal and the frequency-divided signal generate a phase difference signal according to the reference frequency signal and the frequency-divided signal; a loop filter coupled to the phase frequency detector to receive the phase difference signal, and according to the phase difference The signal generates a control signal; a voltage controlled oscillator coupled to the loop filter to receive the control signal, and generates the oscillation signal according to the control signal; and a multi-modulus frequency divider, The phase frequency detector, the voltage controlled oscillator, and the quantizer are coupled to the frequency division control signal to perform frequency division on the oscillation signal to generate the frequency division signal.

如申請專利範圍第6項所述的訊號調變電路，其中該量化器為差異積分調變器(delta-sigma modulator)。 The signal modulation circuit of claim 6, wherein the quantizer is a delta-sigma modulator.

如申請專利範圍第5項所述的訊號調變電路，其中該基頻處理單元包括：一亂數產生器，用以依據該輸入訊號產生一同相位輸入訊號與一正交相位輸入訊號；一基頻濾波器，用以分別對該同相位輸入訊號與該正交相位輸入訊號進行一濾波處理；以及一數位預失真器，接收經該濾波處理後的該同相位輸入訊號與正交相位輸入訊號以及該量化誤差訊號，其中該數位預失真器用以基於CORDIC演算法，以該量化誤差訊號對所接收的該同相位輸入訊號與該正交相位輸入訊號進行相位轉換，藉以產生該組預失真訊號。 The signal modulation circuit according to claim 5, wherein the fundamental frequency The processing unit includes: a random number generator for generating a phase input signal and a quadrature phase input signal according to the input signal; and a fundamental frequency filter for respectively inputting the same phase input signal and the quadrature phase input The signal performs a filtering process; and a digital predistorter receives the filtered in-phase input signal and the quadrature phase input signal and the quantized error signal, wherein the digital predistorter is used based on the CORDIC algorithm The quantized error signal phase-converts the received in-phase input signal and the quadrature-phase input signal to generate the set of pre-distortion signals.

一種無線通訊系統的收發機，包括：一訊號調變電路，包括：一頻率合成器，依據一參考頻率訊號產生一振盪訊號，並且依據經一量化處理所獲得的一除頻控制訊號對該振盪訊號進行除頻，藉以產生一除頻訊號作為該頻率合成器的回授訊號，其中該頻率合成器更產生指示該量化處理所造成的一量化雜訊大小的一量化誤差訊號；一基頻處理單元，耦接該頻率合成器，用以接收一輸入訊號，並且對該輸入訊號與該量化誤差訊號進行一預失真處理，藉以產生一組正交的預失真訊號；以及一調變單元，耦接該頻率合成器與該基頻處理單元，用以接收該組預失真訊號與該振盪訊號，並且依據該振盪訊號對該組預失真訊號進行調變，從而產生一輸出訊號；以及一射頻電路，耦接該訊號調變電路以接收該輸出訊號，並且用以基於該輸出訊號進行一射頻訊號處理。 A transceiver for a wireless communication system, comprising: a signal modulation circuit, comprising: a frequency synthesizer, generating an oscillation signal according to a reference frequency signal, and according to a frequency division control signal obtained by a quantization process The oscillating signal is divided to generate a frequency-divided signal as a feedback signal of the frequency synthesizer, wherein the frequency synthesizer further generates a quantization error signal indicating a quantization noise caused by the quantization process; The processing unit is coupled to the frequency synthesizer for receiving an input signal, and performing a predistortion process on the input signal and the quantized error signal to generate a set of orthogonal predistortion signals; and a modulation unit, The frequency synthesizer and the baseband processing unit are coupled to receive the set of predistortion signals and the oscillation signal, and according to the oscillation signal The group pre-distortion signal is modulated to generate an output signal; and a radio frequency circuit is coupled to the signal modulation circuit for receiving the output signal and for performing an RF signal processing based on the output signal.