CN1714499A - Apparatus and method for wideband signal processing - Google Patents

Abstract

This application discloses an apparatus for electromagnetic processing, the apparatus comprising: a modulator for generating one or more component representations of an input signal; a frequency divider controlled by the one or more components and receiving electromagnetic waves to generate a modified signal; a comparator for comparing the modified signal with a reference signal and generating a processed signal based on the comparison; and a channel number calculator for selecting a channel for the processed signal, wherein the input signal includes the channel selection.

Description

Apparatus and method for wideband signal processing

technical field

The present invention relates generally to electromagnetic processing, and more particularly to broadband signal processing.

Background technique

Electromagnetic waves and signals (hereinafter referred to as "waves") are used for many different purposes. For example, electromagnetic waves may be processed to convey information, such as by reducing and/or amplifying characteristics of the electromagnetic waves, as seen when modulating the amplitude, frequency, or phase of electrical current or radio frequency (RF) waves to transmit data. As another example, by reducing and/or amplifying properties of electromagnetic waves, energy can be transferred in a controlled manner along the waves, as seen when voltage and current in electrical circuits are modulated. Furthermore, these uses can be combined, for example when processing power characteristics can convey information via waves.

Electromagnetic wave characteristic processing can be realized by digital or analog technology. Digital and analog attenuation and/or amplification can also be combined, that is to say various types of digital and/or analog reduction and/or amplification can be performed on the same wave in one system to achieve the desired task.

However, dealing with electromagnetic wave properties can be difficult. For example, selecting an appropriate technique or device to modify wave properties can be difficult for several reasons. One of these reasons includes the type of wave to modify. For example, low frequency waves, such as 60Hz power waves, may require different processing techniques than high frequency waves, such as 24GHz radar waves. So usually different devices with different characteristics are used for different waves. For example, switching semiconductors used in computers for 60Hz power waves have different power handling characteristics than power semiconductors used in 24GHz radar systems.

One attempt at standardizing recently used technologies and devices is to use the properties of the waves as information to modify the waves. For example, by converting waves to polar coordinates with magnitude and phase properties, either or both properties can be used and/or manipulated to provide a normalization technique for various wave frequencies. However, such attempts to date have been hampered by application difficulties. For example, attempts to use multiple amplifiers have suffered from attendant difficulties in amplifier combining. Specifically, the outputs of the amplifiers are summed using devices such as transformers or quarter-wave lines to drive the load. These devices add cost and size to the amplifier array.

Therefore, providing an efficient and at the same time precise technique for processing electromagnetic waves would be helpful to the electromagnetic processing technology.

Contents of the invention

Embodiments of the invention include devices, methods and articles of manufacture for processing electromagnetic waves and signals. In one embodiment, an apparatus for electromagnetic wave processing is provided, comprising: a modulator for generating one or more components representative of an input signal; a frequency divider controlled by the one or more components and receiving an electromagnetic wave to generate a modified signal; a comparator for comparing the modified signal with a reference signal and generating a processed signal based on said comparison; and a channel number calculator for selecting a channel for the processed signal, wherein The input signal includes a channel selection.

In another embodiment, there is provided a method of broadband processing a phase component signal, comprising: generating one or more components representative of an input signal; dividing an electromagnetic wave based on the one or more components to produce an already a modified signal; comparing the modified signal to a reference signal; and generating a processed signal based on the comparison.

Description of drawings

FIG. 1 is a block diagram illustrating an exemplary transmitter.

FIG. 2 is a block diagram illustrating an embodiment of a wideband modulator used in the transmitter of FIG. 1 .

FIG. 3 is a schematic diagram showing an embodiment of a sigma-delta modulator used in the wideband modulator of FIG. 2 .

FIG. 4 is a schematic diagram showing another embodiment of a delta-sigma modulator used in the wideband modulator of FIG. 2 .

Detailed ways

Embodiments of the invention include devices, methods and articles of manufacture for processing electromagnetic waves and signals. To illustrate, exemplary embodiments include broadband modulators suitable for processing electromagnetic waves and signals. The wideband modulators disclosed herein can be implemented in a wide range of applications, eg, transmitters, receivers, converters, and the like. For illustration, an exemplary transmitter is disclosed in FIG. 1, which incorporates the

Embodiment wideband modulator.

The exemplary transmitter 10 shown in FIG. 1 may include, for example, a baseband processor 100 adapted to receive an input signal, an amplitude/phase signal processor 101, a wideband modulator 102, an adaptive phase realignment device 103, a power amplifier 104 and one or more load lines 105 connected to the antenna. Details of transmitter 10 and its various components are described in more detail below.

The term "signal" as used herein should be broadly understood to include any means of transferring data from one place to another, such as an electric current or an electromagnetic field, including but not limited to direct current, or alternating current, or An electromagnetic carrier wave containing one or more data streams. For example, data can be added to the carrier current or carrier by means of modulation, and can be realized in the form of analog or digital. The term "data" as used herein should also be broadly understood to include any type of information or other information, such as but not limited to audio such as sound, text and/or video, and the like.

As shown in FIG. 1 , the baseband processor 100 in this embodiment may include a digital signal processor, for example, a digital signal processor capable of generating power control signals and data control signals in response to an input signal such as a baseband signal. As described in more detail below, electrical power may be regulated by a data control signal to produce an output signal for transmission that is an amplified input signal.

The data control signal generated by the baseband processor 100 in this embodiment includes electromagnetic waves containing data derived from the input signal. Data control signals are transmitted from the baseband processor 100 to the magnitude/phase signal processor 101 .

In one embodiment, the I and Q data are converted to polar signals by the baseband processor 100 to generate an analog or digital data control signal comprising the amplitude wave characteristic am of the input signal and an electromagnetic control signal comprising the phase wave characteristic ap of the input signal. Signal. For example, a Cartesian to Polar converter can be used to output polar coordinates in the form of R, P(sin) and P(cos). The R coordinate represents the wave amplitude characteristic. The P(sin) and P(cos) coordinates represent the phase characteristics of the wave.

The magnitude and phase characteristics of the input signal may then be sent to the power amplifier 104 via separate paths. The amplitude characteristics of the original signal may be modulated into a digital pulse train comprising a digital word quantized into bits _B0 to Bn _-1 having the most significant bit to the least significant bit, the length of the digital word in various embodiments can change.

In turn, the phase characteristics can be processed separately and then applied to the power amplifier 104 . Fig. 2 shows an exemplary way of processing phase characteristics. FIG. 2 shows in detail an exemplary embodiment for the signal processor 101 , wideband modulator 102 and adaptive phase realigner 103 of FIG. 1 .

In this embodiment, the phase data from the input signal first preferably passes through the data scaling processor 120, which properly scales the amplitude of the data signal. Changes in the amplitude of the signal produced by the data scaling processor 120 are calculated to compensate for any gain in the output signal from the wideband modulator 102 . Scaling of the signal may be accomplished by any conventional means compatible with the data format, eg, in a preferred embodiment, the phase data signal is digital and scaling may be accomplished by digital processing. In this embodiment, the broadband modulator 102 is essentially a frequency modulator, so that the data is converted according to dθ/dt 123 shown in FIG. 2 for the representation of the frequency and phase of the data.

The phase component signal then preferably passes through a modulation compensation (equalization) filter 121 that is calculated to have a magnitude and phase response that is the inverse of the closed-loop response of the wideband modulator 102 . As will be discussed below, in some cases modulator 102 has an internal bandwidth designed to minimize noise in the signal. However, limiting the bandwidth in this way may cause a reduction, ie attenuation, of the higher frequency components of the signal. Equalization filter 121 and overall modulation response filter 122 compensate for attenuation by increasing the gain of these higher frequency components, thus producing a flatter (smoother) frequency response for the system and effectively extending the modulation bandwidth of wideband modulator 102 . The equalization filter 121 is preferably digitally implemented by using a digital signal processor, but is not limited thereto, and as an example, the equalization filter 121 may be a FIR (finite impulse response) or IIR (infinite frequency response) filter. The phase component data may also pass through an overall modulation response filter 122, which is calculated to set the overall passband response of the wideband modulator 102 (eg, 4 MHz). Like equalization filter 121, total modulation response filter 122 may be an analog or digital FIR or IIR filter. Functionally, filters 121 and 122 can be combined to form a desired signal filter.

In this embodiment, the baseband input signal may be modulated onto a carrier at a center frequency selected in wideband modulator 102 . The center frequency onto which a given signal is to be modulated is determined by channel calculation, which divides the carrier frequency (such as 1880 MHz) by the frequency of the reference source to establish a channel for the signal.

In this embodiment, the channel calculation produces a number with an integer part and a fractional part. As shown in FIG. 2, channel calculator 124 receives the channel number from baseband processor 100 and determines an optional non-whole number by which to divide the carrier of wideband modulator 102, allowing selection of the phase The channel on which the data signal is modulated. As an illustration of the channel calculation process, assuming that the carrier frequency is 1880MHz as an example, this number can be between 23.5 and 24.5 because it is determined from the reference frequency. The fractional portion of the number is then combined with the data signal, and the combined signal is passed to a delta-sigma modulator (SDM) 125 in wideband modulator 102 . The SDM 125 is used in conjunction with a phase-locked loop (PLL) 126 to realize broadband modulation of the carrier using the input signal. The SDM 125 is used to randomize the input phase data and oversample it such that the average of multiple samples of the output is equal to the input. The way the SDM 125 works in this embodiment is to frequency shape the internal quantization noise from the digitization process so that at the desired frequencies, the noise is low.

SDM 125 may include, for example, a series of adders/accumulators and feedback devices for inputting fractional phase/channel number data (which may be analog or digital) and outputting a series of digitized integers equal to the fractional input. In this embodiment the SDM 125 is preferably configured in such a way that the input range is sufficient for phase modulated data and fractions of the channel number. In an exemplary embodiment, the SDM 125 is a 3-bit system, so it can generate 8 different output numbers (such as -3, -2, -1, 0, 1, 2, 3, and 4), but should It is understood that in another embodiment the SDM 125 may include any desired number of bits or elements. In this embodiment, the SDM 125 preferably produces 4 output integers per input sample, resulting in an oversampling ratio of four times the input. Sampling the input modulated data in this manner in the SDM 125 may introduce noise to the input modulated signal. Any such noise can be filtered out by low pass loop filter 131 in PLL 126. Figures 3 and 4 show two exemplary circuit topologies for the SDM125. Figure 3 shows the MASH III topology, and Figure 4 shows the third-order loop topology. However, it should be understood that other suitable circuit topologies may be used for SDM 125 if desired.

The output of the SDM 125 in this embodiment is then combined with the integer portion of the channel number received from the channel calculator 124. In the example discussed here, this combination will produce numbers between 20 and 28. The combination of the fractional and integer parts of the channel number in this embodiment is input into frequency divider 128 and used to lock PLL 126 to the desired RF carrier.

In this embodiment, PLL 126 is preferably used to modulate a carrier signal that has been synthesized by an RF carrier signal source, such as carrier source 129, with the phase portion of the input signal. The carrier wave source 129 may be any electromagnetic wave source capable of generating a carrier wave, such as a radio frequency voltage-controlled oscillator (VCO).

As shown in Figure 2, in the present embodiment, the frequency of the reference source 127 (or its frequency division by a certain number) is compared with the output frequency of the carrier source 129, and its frequency is obtained from the SDM 125 by the frequency divider 128 and a series of numbers received by the channel calculator 124 for frequency division. Reference source 127 may comprise a fixed or substantially fixed frequency VCO, or may be derived from a source of another frequency.

As shown in FIG. 2, a phase frequency detector (PFD) 130 is used to compare the relative phases of two signals, and then output a signal proportional to the deviation (phase shift) between them. This output signal is used to adjust the frequency of carrier source 129 so that the phase deviation measured at PFD 130 is substantially close to and preferably equal to zero. Thus, the phase of the signal is locked by the feedback loop to prevent undesired shifts in the phase of the signal due to changes in the phase and frequency of the carrier source 129 (eg, distortion).

As shown in Figure 2, the feedback signal from the carrier source 129 passes through the frequency divider 128, and the frequency division ratio of the frequency divider is determined by a series of numbers representing the phase component information received from the SDM 125 and the channel information received from the channel calculator 124 control. The resulting signal is passed to PFD 130 and compared to the signal from reference source 127 as described above. This combined signal is passed through a low pass loop filter 131 and combined with the carrier signal of carrier source 129 .

In this embodiment, the SDM 125 is used to perform broadband modulation of the phase data input into the SDM 125. Since the phase data input into the SDM 125 is not constant, synchronizing the SDM 125 with the output of the frequency divider 128 may cause a frequency offset depending on the modulating signal. Therefore, it may be desirable in certain embodiments to synchronize SDM 125 and frequency divider 128 by reference source 127. For example, a buffer may be used between the output of SDM 125 and the input of frequency divider 128 so that frequency divider 128 can complete the divided count before updating the new series of sample numbers.

As shown in FIG. 1 , adaptive phase realigner 103 can also be used to dynamically adjust the PLL response to ensure that the closed-loop responses of equalization filter 121 and PLL 126 are closely matched. Adaptive phase realigner 103 preferably measures the output phase of wideband modulator 102 and compares it to a theoretically perfect version derived from the baseband input data and center frequency information derived from channel calculator 124 . The result of this comparison is used to adjust the loop gain of PLL 126 in wideband modulator 102. This feedback system works to minimize the error of the transmitted signal. Adaptive phase realigner 103 works best when the transmitter is in service and there is less need for manual calibration of the system.

An exemplary embodiment of the adaptive phase realigner 103 is shown in detail in FIG. 2 . It should be understood that other suitable embodiments of adaptive phase realigner 103 may be used if desired. The adaptive phase realigner 103 shown in FIG. 2 may include, for example, a digital phase-locked loop (DPPL) 140, a reference error filter 142, a carrier phase detector/tracking and keeper 144, a gain error detector 146, and RF phase quantizer 148 .

The DPLL 140 aligns the ideal phase with the actual RF phase by removing any constant phase offset Φ and random _{drift Tdrift} due to delays through the SDM and RF quantization demodulation processes.

RF_VCO_Out＝cos(ω _c t+K _tot (1+δ)d _n ∫g(t)dt+w _drift +Φ)

Reference error filter 142 generates a reference phase error waveform from the estimated loop filter transfer function. This reference error signal basically serves as a measure of the true phase error. The polarity of the PLL gain error preferably matches the polarity of the autocalibration feedback output by multiplying the true phase error signal and the reference phase error signal. Furthermore, the average value of the autocalibration feedback output is preferably proportional to the magnitude of the PLL gain error (regardless of the polarity of the phase information signal).

The carrier phase detector/track and hold 144 directly compares the digitally summed carrier and phase (ideal) to the sampled VCO RF true phase output. The carrier phase detector/tracker and keeper 144 removes phase ambiguity, such as 2p-radians of phase ambiguity. And provide phase/frequency detection.

Gain error detector 146 generates a delta of estimated PLL gain error and provides a corrected signal to the PLL frequency phase detector to adjust loop gain.

The RF phase quantizer 148 is used to sample the RF carrier to extract baseband phase information to reproduce the modulated signal. This function can be implemented using, for example, an A/D converter.

Returning now to Figure 1, the processed wave output from the broadband modulator 102 preferably has a constant envelope, ie it has no variation in amplitude, yet it has the phase characteristics of the original input wave. The output wave is then sent where needed, such as a power amplifier 104, which may include any of a number of suitable amplifier devices. In an exemplary embodiment, the power amplifier 104 is suitable as a current source when it is properly regulated according to the digital word output from the magnitude component. The amplitude portion of the input signal is transmitted separately from the amplitude/phase signal processor 101 to the power amplifier 104 and can be used to act on various stages in the power amplifier 104 to amplify or attenuate the phase modulated carrier signal relative to the original input signal. This produces an output current from the power amplifier 104 that represents the amplified or attenuated carrier containing information from the input signal.

In some embodiments, such as those with transmitters, receivers, and radio transceivers, these devices can be customized for specific input signals, carriers, and output signals, for example, various cellular phones such as CDMA, CDMA2000, W-CDMA, GSM, TDMA, and various other types of wired and wireless devices such as Bluetooth, 802.11a, -b, -g, radar, 1×RTT, radio, GPRS, computer and computer or non-computer communication equipment , handheld devices, etc. Among the modulation schemes supported by various embodiments are: for example, GMSK, which is used for GSM; GFSK, which is used for DECT and Bluetooth; 8-PSK, which is used for EDGE; OQPSK and HPSK, which is used for IS-2000 ; p/4DQPSK, which is used in TDMA; OFDM, which is used in 802.11.

Embodiments may use analog and digital devices, where desired, since analog and digital devices are required to control the processing waves and signals in these embodiments. For example, a cellular telephone embodiment may use both analog and digital devices. Embodiments may be constructed using various types of system configurations. For example, where desired, embodiments or various devices are disposed on semiconductor devices, such as integrated circuits or components of application-specific integrated circuits, some examples including silicon (Si), silicon germanium (SiGe), or gallium arsenide ( GaAs) substrate.

Having described several particular embodiments of the invention, such alterations, modifications and improvements will readily occur to those skilled in the art. Such obvious alterations, modifications and improvements as made to this disclosure are intended to be part of this description, although not directly stated herein, and are to be included within the spirit and scope of the invention. Those skilled in the art will thus understand that embodiments of the present invention or such devices and/or characteristics of devices may consist entirely of hardware, software and/or may be a combination of software and hardware. Accordingly, each block of the drawings, and combinations of blocks of the drawings, may be implemented in many different ways, as is well known to those skilled in the art. Accordingly, the foregoing description is by way of example only, not limitation. The invention is intended to be limited only as defined by the following claims and their equivalents.

Claims (32)

1, a kind of method that phase component signal is carried out the broadband processing comprises:

Be used to produce one or more component representatives of input signal;

Based on described one or more components electromagnetic wave is carried out frequency division to produce the signal of having revised;

More described signal of having revised and reference signal; And

Result based on the comparison produces the signal of having handled.

2, method according to claim 1 also comprises:

Be the described signal selective channel of having handled, wherein said input signal comprises described channel selection.

3, method according to claim 2, wherein, described channel is selected by two representation in components, first component is included in the described input signal, second component comprises second input signal, and wherein said combination step comprises that also described second input signal of combination and described electromagnetic one or more components are to produce the signal of having revised.

4, method according to claim 3 also comprises:

Select to calculate described first component and described second component based on channel.

5, method according to claim 4, wherein, described channel is selected to be specified by a number, and described first component comprises the fractional part of described number, and described second component comprises the integer part of described number.

6, method according to claim 3 also comprises:

Make up described first component and second electromagnetic wave so that described input signal to be provided.

7, method according to claim 6 also comprises:

With described first component combination before handle described second electromagnetic wave.

8, method according to claim 7, wherein said treatment step comprises equalization filtering.

9, method according to claim 7, wherein said treatment step comprises calibration.

10, method according to claim 7, wherein said treatment step comprises modulated response filtering.

11, method according to claim 7 wherein also comprises compensation detected error in described processed signal based on the described step of having revised the comparison of signal and reference signal and having produced processed signal.

12, method according to claim 11, wherein said compensation process comprise from described second electromagnetic wave and obtaining with reference to electromagnetic wave, and adjust the described signal of having revised based on described with reference to electromagnetic wave

13, a kind of device that phase component signal is carried out the broadband processing comprises:

Be used to produce the means of one or more components representatives of input signal;

Based on described one or more components electromagnetic wave is carried out frequency division to produce the means of the signal of having revised;

The means of more described signal of having revised and reference signal; And

Based on the described means that relatively produce processed signal.

14, device according to claim 13 also comprises:

Be the means of described processed signal selective channel, wherein said input signal comprises described channel selection.

15, device according to claim 14, wherein said channel is selected by two representation in components, first component is included in the described input signal, second component comprises second input signal, wherein described second input signal and described one or more component and described electromagnetic wave is made up to produce the described signal of having revised.

16, device according to claim 15 also comprises:

Select to calculate the means of described first component and described second component based on channel, wherein said channel is selected to be specified by a number, and described first component comprises the fractional part of described number, and described second component comprises the integer part of described number.

17, device according to claim 16 also comprises:

With described first component combination before handle the described second electromagnetic means.

18, device according to claim 17, wherein said processing means comprise one or more means of selecting from the group of being made of compensating filter, calibration processor and modulated response filter.

19, device according to claim 18 also comprises compensation detected error in described processed signal.

20, device according to claim 19, wherein said compensatory device comprise from described second electromagnetic wave and obtaining with reference to electromagnetic wave, and adjust the described signal of having revised based on described with reference to electromagnetic wave.

21, a kind of Electromagnetic Treatment device comprises:

Modulator, the one or more component representatives that are used to produce input signal;

Frequency divider produces the signal of having revised by described one or more component controls and reception electromagnetic wave;

Comparator, the signal that is used for more described signal of having revised and reference signal and has handled based on described relatively generation.

Number of channel calculator is used to described processed signal selective channel, and wherein said input signal comprises described channel selection.

22, device according to claim 21 also comprises

Channel calculator, be used for described channel is selected to be appointed as by two representation in components, first component is included in the described input signal, second component comprises second input signal, wherein described second input signal and described one or more component and described electromagnetic wave is made up to produce the described signal of having revised.

23, device according to claim 22, wherein said channel is selected to be specified by a number, and described first component comprises the fractional part of described number, described second component comprises the integer part of described number, and wherein said first component and second electromagnetic wave combine provides described input signal.

24, device according to claim 23 also comprises: compensating filter, calibration processor and modulated response filter.

25, device according to claim 24, also comprise the self adaptation phase place aim at again device with the compensation in described processed signal detected error.

26, device according to claim 21, wherein the self adaptation phase place is aimed at device again and is communicated by letter with described comparator, and from described second electromagnetic wave, obtain, wherein when adjusting the described signal of having revised during with reference to the error of Electromagnetic Wave Detection in described processed signal based on described with reference to electromagnetic wave.

27, a kind of Electromagnetic Treatment device comprises:

Modulator, the one or more component representatives that are used to produce input signal;

Frequency divider produces the signal of having revised by described one or more component controls and reception electromagnetic wave;

Comparator, the signal that is used for more described signal of having revised and reference signal and has handled based on described relatively generation; With

The self adaptation phase place is aimed at device again, is used for compensation in the detected error of described processed signal.

28, device according to claim 27, wherein the self adaptation phase place is aimed at device again and is communicated by letter with described comparator, and from described second electromagnetic wave, obtain, wherein when adjusting the described signal of having revised during with reference to the error of Electromagnetic Wave Detection in described processed signal based on described with reference to electromagnetic wave.

29, device according to claim 28 also comprises:

Number of channel calculator is used to described processed signal selective channel, and wherein said input signal comprises described channel selection.

30, device according to claim 29 also comprises:

Channel calculator, be used for described channel is selected to be appointed as by two representation in components, first component is included in the described input signal, second component comprises second input signal, wherein described second input signal and described one or more component and described electromagnetic wave is made up to produce the described signal of having revised.

31, device according to claim 30, wherein said channel is selected to be specified by a number, and described first component comprises the fractional part of described number, described second component comprises the integer part of described number, and wherein said first component and second electromagnetic wave combine provides described input signal.

32, device according to claim 23 also comprises: one or more devices of selecting from the group that compensating filter, calibration processor and modulated response filter are formed.

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