Multi-channel signal receiving system, transceiver and communication system

Abstract

This invention provides a multi-channel signal receiving system, transceiver, and communication system. The system includes: multiple preprocessing circuits, each corresponding to a different input channel, for preprocessing the input signals received by each input channel; multiple first chopper circuits, each connected to one of the preprocessing circuits, wherein the first chopper circuits are turned off when the frequency bands of the input signals are different, and turned on when the frequency bands of the input signals are the same, adjusting the frequency band of each input signal to make them different; an analog-to-digital conversion circuit connected to each of the first chopper circuits for quantizing each input signal; and a digital processing terminal connected to the analog-to-digital conversion circuits for data recovery of the quantized input signals. This solution enables multi-channel signal reception and reduces the required number of hardware components, thereby reducing chip area and cost.

Description

Technical Field

[0001] This invention relates to the field of communication system technology, and more particularly to a multi-channel signal receiving system, transceiver, and communication system. Background Technology

[0002] In modern communication systems, it has become a trend for single-chip transceivers to integrate more input and output channels. For the receiving channels, each channel has the same but independent hardware configuration. Therefore, as the number of receiving channels increases, the corresponding chip area also increases proportionally, leading to a significant increase in chip cost. Thus, there is an urgent need for a multi-channel signal receiving system that can accommodate multiple receiving channels while reducing the number of hardware components, chip area, and cost. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-channel signal receiving system, transceiver, and communication system that can achieve multi-channel signal reception and reduce the number of required hardware components, thereby reducing chip area and cost.

[0004] The technical solutions provided by the present invention are as follows:

[0005] In a first aspect, the present invention provides a multi-channel signal receiving system, comprising:

[0006] Multiple preprocessing circuits, each corresponding to a specific input channel, are used to preprocess the input signals received by each input channel.

[0007] Multiple first chopper circuits are connected one-to-one with each of the preprocessing circuits. The first chopper circuit is turned off when the frequency bands of the input signals are different and directly inputs the input signals to the analog-to-digital conversion circuit. The first chopper circuit is turned on when the frequency bands of the input signals are the same and inputs the input signals to the analog-to-digital conversion circuit after adjusting the frequency bands of each input signal to make the frequency bands of the input signals different.

[0008] An analog-to-digital converter circuit, wherein the input terminal of the analog-to-digital converter circuit is connected to each of the first chopper circuits, and is used to quantize each of the input signals;

[0009] The digital processing terminal is connected to the output terminal of the analog-to-digital conversion circuit and is used to recover data from each of the quantized input signals.

[0010] This solution integrates a preprocessing circuit at the receiver front end to preprocess the input signals from each channel. The use of the chopper circuit is selected based on the actual application scenario. If the input signal frequency bands of the multiple input channels are already differentiated, the chopper circuit is turned off. The signal subsequently converted by the analog-to-digital converter and input to the digital processing end only needs to be filtered again for signal recovery. If the multiple input channels are signals with the same frequency band, the chopper circuit is turned on, and the frequency band of each channel is planned to ensure that the channels do not interfere with each other in the spectrum. The signal subsequently converted by the analog-to-digital converter and input to the digital processing end can be recovered by adjusting the corresponding frequency band through a second chopper circuit. This allows multiple inputs to share a single wideband ADC, reducing the increase in hardware costs. Furthermore, it avoids the use of complex mixers at the input end; a simple chopper circuit structure can achieve the shifting of the input signal spectrum, making the input path structure simpler. This reduces the required number of hardware components while receiving multiple signals, thereby reducing chip area and cost.

[0011] In some implementations, the control signal of the control switch of the first chopper circuit is generated by frequency division of the sampling clock of the analog-to-digital converter circuit.

[0012] This solution avoids using complex mixers at the input end and adopts a simple chopper circuit to achieve input spectrum shifting. The chopper circuit does not require a local oscillator signal, and the input clock can be obtained by dividing the ADC sampling clock, thus making the input path structure simpler. Most of the signal processing can be digitally processed by a wideband ADC, which is in line with the trend of advanced CMOS process development.

[0013] In some embodiments, the first chopper circuit includes two sets of high-frequency switches, the first set of high-frequency switches including a first switch and a second switch, and the second set of high-frequency switches including a third switch and a fourth switch;

[0014] The first terminal of the first switch and the first terminal of the second switch are connected to the positive terminal of the input signal, and the first terminal of the third switch and the first terminal of the fourth switch are connected to the negative terminal of the input signal.

[0015] The second terminal of the first switch and the second terminal of the fourth switch are used to connect to the analog-to-digital conversion circuit, the second terminal of the second switch is connected to the second terminal of the fourth switch, and the second terminal of the third switch is connected to the second terminal of the first switch;

[0016] The second terminals of the first switch and the fourth switch are also grounded through capacitors.

[0017] In some embodiments, the preprocessing circuit includes a variable gain amplifier and a first filter, used for signal amplification and filtering of the input signal, respectively.

[0018] In some embodiments, the digital processing terminal includes multiple signal processing circuits, each of which corresponds to one of the input channels.

[0019] The signal processing circuit includes a second chopper circuit and a second filter. The second chopper circuit is turned off when the frequency bands of the various input signals are different, and the quantized input signals are directly input to the corresponding second filter for data recovery.

[0020] The second chopper circuit is activated when the frequency bands of each input signal are the same, and the quantized input signals are recovered by adjusting the frequency band of the corresponding second chopper circuit and filtering by the second filter.

[0021] In some embodiments, when the frequency bands of the various input signals are different, the second filter performs data recovery on the corresponding quantized input signals according to the frequency bands of the respective input signals.

[0022] In some implementations, the first chopper circuit corresponding to the same input channel adjusts the frequency band of the input signal in opposite directions and the second chopper circuit adjusts the frequency band of the quantized input signal in the same direction, but with the same adjustment magnitude.

[0023] In some implementations, the frequency ranges of the input signals with the same frequency band are adjusted to be different by assigning different frequencies to each of the first chopper circuits.

[0024] Secondly, this application provides a transceiver including the multi-channel signal receiving system described in the first aspect.

[0025] Thirdly, this application provides a communication system including the transceiver described in the second aspect.

[0026] The multi-channel signal receiving system, transceiver, and communication system provided by this invention can reduce the increase in hardware costs by enabling multiple inputs to share a single broadband ADC. Furthermore, it avoids the use of complex mixers at the input end and can achieve input spectrum shifting using a simple chopper circuit, making the input path structure simpler. This allows for a reduction in the number of required hardware components while achieving multi-channel signal reception, thereby reducing chip area and cost. Attached Figure Description

[0027] The preferred embodiments will now be described in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of this solution.

[0028] Figure 1 This is a schematic diagram of signal processing with multiple input channels in the prior art;

[0029] Figure 2 This is a schematic diagram of a multi-channel signal receiving system according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of a first chopper circuit according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram illustrating the principle of spectrum shifting via a chopper circuit in one embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of different frequency band input signals according to an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of different frequency band input signals after ADC quantization according to an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the signal after the spectrum of input signals of different frequency bands is restored by a filter, according to an embodiment of the present invention.

[0035] Figure 8 This is a schematic diagram of the same frequency band input signal according to an embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of the spectrum of an input signal with the same frequency band after passing through a first chopper circuit, according to an embodiment of the present invention.

[0037] Figure 10 This is a schematic diagram of an embodiment of the present invention, showing how the frequency band of an input signal with the same frequency band is adjusted by a first chopper circuit and then quantized by an ADC.

[0038] Figure 11 This is a schematic diagram of the signal after the spectrum of an input signal with the same frequency band is restored by a second chopper circuit and a filter, according to an embodiment of the present invention. Detailed Implementation

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0040] To keep the drawings concise, only the parts relevant to the invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of components with the same structure or function is shown schematically, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one".

[0041] In modern communication systems, it has become a trend for single-chip transceivers to integrate more input and output channels. For the receive channel, each channel has the same but independent hardware configuration. Therefore, as the number of receive channels increases, the corresponding chip area also increases proportionally, resulting in a significant increase in chip cost. For example... Figure 1 As shown, in existing communication systems, each channel of the receiver requires amplification via a variable gain amplifier (VGA), followed by mixing the input signal to a lower frequency band using a mixer, quantization via a low-pass filter (LPF) to an analog-to-digital converter (ADC), and finally, processing by digital circuitry. The local oscillator (LO) signal of the mixer requires a dedicated frequency generation module, and different LO frequencies are needed for different input bands, necessitating a more complex hardware structure. Therefore, there is an urgent need for a multi-channel signal receiving system that can accommodate multiple receiving channels while reducing hardware quantity, chip area, and cost. This solution reduces hardware cost by sharing a single wideband ADC across multiple inputs. Furthermore, it avoids using complex mixers at the input end, employing a simple chopper circuit to shift the input signal spectrum. The chopper circuit does not require a LO signal; the input clock can be obtained by dividing the ADC sampling clock, thus simplifying the input path structure. Most signal processing can be performed digitally using the wideband ADC, aligning with the trend of advanced CMOS technology development. This achieves a reduction in the required hardware quantity, thereby lowering chip area and cost, while still enabling multi-channel signal reception. The following is a detailed description of this solution with reference to the accompanying drawings:

[0042] In one embodiment, refer to the appendix to the specification. Figure 2 This invention provides a multi-channel signal receiving system, comprising: multiple preprocessing circuits 10, multiple first chopper circuits 20, an analog-to-digital converter circuit 30, and a digital processing terminal 40. The multiple preprocessing circuits 10 correspond to each input channel and are used to preprocess the input signal received by each input channel. Each preprocessing circuit 10 includes a variable gain amplifier 11 and a first filter 12, used for signal amplification and filtering of the input signal, respectively.

[0043] Multiple first chopper circuits 20 are connected one-to-one with each preprocessing circuit 10. The first chopper circuit 20 employs chopping technology, a technique that modulates continuous signals with pulse signals through rapid switching (usually high-frequency switching). The first chopper circuit 20 is turned off when the frequency bands of the input signals are different, and the input signals are directly input to the analog-to-digital converter circuit 30. The first chopper circuit 20 is turned on when the frequency bands of the input signals are the same, and after adjusting the frequency bands of each input signal to make them different, the input signals are input to the analog-to-digital converter circuit 30. This solution selects whether to use the function of the first chopper circuit 20 based on the actual application scenario. If the frequency bands of the input signals from multiple input channels are already distinguished, the first chopper circuit 20 is turned off, and the input signals are directly input to the analog-to-digital converter circuit 30. If the multiple input channels are input signals with the same frequency band, the first chopper circuit 20 is turned on, the frequency band of each channel is re-planned, and after adjusting the frequency band of each input signal to be different, the signal is input to the analog-to-digital converter circuit 30.

[0044] Specifically, by assigning different frequencies to each of the first chopper circuits 20, the frequency ranges of input signals with the same frequency band can be adjusted to be different. For example, for four input signals with a bandwidth less than 1 / 12 fs, the chop clock can be set to 0, 1 / 6 fs, 1 / 3 fs, and 1 / 2 fs, which can adjust the input signals to different frequency bands. The above chop frequencies will adjust the inputs of the four channels to the following frequency bands (0-1 / 12 fs, 1 / 12 fs~2 / 12 fs, 3 / 12 fs~4 / 12 fs, 5 / 12 fs~6 / 12 fs). For narrowband applications, the chop frequency interval can be further reduced to plan for applications with more channels.

[0045] The input terminals of the analog-to-digital converter (ADC) 30 are connected to each of the first chopper circuits 20 for quantizing each input signal. This application uses a single wideband ADC for multiple inputs, thereby reducing the increase in hardware cost. Compared to using multiple narrowband ADCs, using a single wideband ADC allows for frequency division multiplexing of the input through chopper circuits, making the analog front-end filter easier to implement. The digital processing terminal 40 is connected to the output terminal of the ADC 30 for data recovery of each quantized input signal, thereby realizing the reception and quantization of the input signals of each input channel.

[0046] This solution integrates a preprocessing circuit at the receiver front end to preprocess the input signals from each channel. The use of the chopper circuit is selected based on the actual application scenario. If the input signal frequency bands of the multiple input channels are already differentiated, the chopper circuit is turned off. The signal subsequently converted by the analog-to-digital converter and input to the digital processing end only needs to be filtered again for signal recovery. If the multiple input channels are signals with the same frequency band, the chopper circuit is turned on, and the frequency band of each channel is planned to ensure that the channels do not interfere with each other in the spectrum. The signal subsequently converted by the analog-to-digital converter and input to the digital processing end can be recovered by adjusting the corresponding frequency band through a second chopper circuit. This allows multiple inputs to share a single wideband ADC, reducing the increase in hardware costs. Furthermore, it avoids the use of complex mixers at the input end; a simple chopper circuit structure can achieve the shifting of the input signal spectrum, making the input path structure simpler. This reduces the required number of hardware components while receiving multiple signals, thereby reducing chip area and cost.

[0047] In one specific implementation, the control signal of the control switch of the first chopper circuit 20 is generated by frequency division of the sampling clock of the analog-to-digital converter circuit 30.

[0048] To avoid using a complex mixer at the input end, this solution employs a simple chopper circuit to shift the input spectrum. The chopper circuit does not require a local oscillator signal, and the input clock can be obtained by dividing the ADC sampling clock, thus simplifying the input path structure. This allows the chopper circuit clock to reuse the ADC sampling clock, and most signal processing can be performed digitally using a wideband ADC, which aligns with the trend of advanced CMOS technology development.

[0049] Specifically, such as Figure 3 As shown, the first chopper circuit 20 includes two sets of high-frequency switches. The first set of high-frequency switches includes a first switch S21 and a second switch S22, and the second set of high-frequency switches includes a third switch S23 and a fourth switch S24. The first terminal of the first switch S21 and the first terminal of the second switch S22 are connected to the positive terminal of the input signal, and the first terminal of the third switch S23 and the first terminal of the fourth switch S24 are connected to the negative terminal of the input signal. The second terminal of the first switch S21 and the second terminal of the fourth switch S24 are used to connect to the analog-to-digital converter circuit 30. The second terminal of the second switch S22 is connected to the second terminal of the fourth switch S24, and the second terminal of the third switch S23 is connected to the second terminal of the first switch S24. The second terminals of the first switch S21 and the fourth switch S24 are also grounded through capacitors.

[0050] In one specific implementation, the digital processing terminal 40 includes multiple signal processing circuits, each corresponding to one of the input channels. Each signal processing circuit includes a second chopper circuit 41 and a second filter 42. The second chopper circuit 41 is turned off when the frequency bands of the input signals are different, and the quantized input signals are directly input to the corresponding second filter 42 for data recovery. The second chopper circuit 41 is turned on when the frequency bands of the input signals are the same, and the quantized input signals are adjusted by the frequency band of the corresponding second chopper circuit 41 and filtered by the second filter 42 to achieve data recovery.

[0051] When the frequency bands of the various input signals are different, the second filter 42 performs data recovery on the corresponding quantized input signals according to the frequency bands of each input signal. The frequency band adjustment of the input signal by the first chopper circuit 20 and the frequency band adjustment of the quantized input signal by the second chopper circuit 41 corresponding to the same input channel are in opposite directions but with the same adjustment magnitude.

[0052] The principle of spectrum shifting through a chopper circuit is as follows: Figure 4 As shown, for an input signal, after the first chopper circuit adjusts the frequency band, a new spectrum will be generated. The new spectrum will be quantized by the ADC and the frequency band will be adjusted by the second chopper circuit, which will generate another new spectrum. Finally, the input signal can be restored by filtering the filter, thereby realizing the reception and quantization of the input signal.

[0053] For example, in the use of the multi-channel signal receiving system of this application, when the frequency bands of the various input signals are different, such as... Figures 5 to 7 As shown, input signals of different frequency bands are directly quantized by the ADC. The quantized input signals are then filtered at the digital processing end to restore their spectrum, thus achieving input signal reconstruction and reception. However, when the frequency bands of the input signals are the same, such as... Figures 8 to 11 As shown, input signals with the same frequency band are first adjusted by the first chopper circuit to ensure that the input signals do not interfere with each other in the spectrum. Then, they are quantized by the ADC. The quantized input signals are then restored to their spectrum by the second chopper circuit and filter at the digital processing end, so as to realize the restoration and reception of the input signals.

[0054] In one embodiment, this application provides a transceiver including the multi-channel signal receiving system of the foregoing embodiments.

[0055] In one embodiment, this application provides a communication system including the transceiver of the foregoing embodiments.

[0056] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multi-channel signal receiving system, characterized in that, include: Multiple preprocessing circuits, each corresponding to a specific input channel, are used to preprocess the input signal received by each input channel. Each preprocessing circuit includes a variable gain amplifier and a first filter, which are used to amplify and filter the input signal, respectively. Multiple first chopper circuits are connected one-to-one with each of the preprocessing circuits. The first chopper circuit is turned off when the frequency bands of the input signals are different and directly inputs the input signals to the analog-to-digital conversion circuit. The first chopper circuit is turned on when the frequency bands of the input signals are the same and inputs the input signals to the analog-to-digital conversion circuit after adjusting the frequency bands of each input signal to make the frequency bands of the input signals different. An analog-to-digital converter circuit, wherein the input terminal of the analog-to-digital converter circuit is connected to each of the first chopper circuits, and is used to quantize each of the input signals; The digital processing terminal, connected to the output of the analog-to-digital conversion circuit, is used to recover data from each of the quantized input signals. The digital processing terminal includes multiple signal processing circuits, each corresponding to one of the input channels. Each signal processing circuit includes a second chopper circuit and a second filter. The second chopper circuit is turned off when the frequency bands of the input signals are different, and directly inputs each of the quantized input signals to the corresponding second filter for data recovery. The second chopper circuit is turned on when the frequency bands of the input signals are the same, and recovers the data from each of the quantized input signals through frequency band adjustment by the corresponding second chopper circuit and filtering by the second filter.

2. The multi-channel signal receiving system according to claim 1, characterized in that, The control signal of the control switch of the first chopper circuit is generated by frequency division of the sampling clock of the analog-to-digital converter circuit.

3. The multi-channel signal receiving system according to claim 2, characterized in that, The first chopper circuit includes two sets of high-frequency switches. The first set of high-frequency switches includes a first switch and a second switch, and the second set of high-frequency switches includes a third switch and a fourth switch. The first terminal of the first switch and the first terminal of the second switch are connected to the positive terminal of the input signal, and the first terminal of the third switch and the first terminal of the fourth switch are connected to the negative terminal of the input signal. The second terminal of the first switch and the second terminal of the fourth switch are used to connect to the analog-to-digital conversion circuit, the second terminal of the second switch is connected to the second terminal of the fourth switch, and the second terminal of the third switch is connected to the second terminal of the first switch; The second terminals of the first switch and the fourth switch are also grounded through capacitors.

4. The multi-channel signal receiving system according to claim 1, characterized in that, When the frequency bands of the various input signals are different, the second filter performs data recovery on the corresponding quantized input signals according to the frequency bands of the various input signals.

5. The multi-channel signal receiving system according to claim 1, characterized in that, The first chopper circuit, corresponding to the same input channel, adjusts the frequency band of the input signal in opposite directions, while the second chopper circuit adjusts the frequency band of the quantized input signal in the same direction, with the same adjustment magnitude.

6. The multi-channel signal receiving system according to claim 1, characterized in that, By assigning different frequencies to each of the first chopper circuits, the frequency ranges of the input signals with the same frequency band can be adjusted to be different.

7. A transceiver, characterized in that, Includes the multi-channel signal receiving system according to any one of claims 1-6.

8. A communication system, characterized in that, Includes the transceiver described in claim 7.

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