Multi-carrier receiving method and multi-carrier receiver

Abstract

The present application discloses a multi-carrier receiving method and a multi-carrier receiver, the multi-carrier receiver includes a signal processing circuit and a plurality of receiving circuits, the receiving circuit includes a processing circuit and a filter switching circuit, the processing circuit down-converts the multi-carrier signal to obtain an intermediate frequency signal; the filter switching circuit includes a selection circuit and a plurality of filters, the filter bandwidths of the plurality of filters are all different, the selection circuit selects a filter to filter the intermediate frequency signal; the signal processing circuit detects whether there is a strong carrier signal in the multi-carrier signal, and when there is a strong carrier signal in the multi-carrier signal, controls the selection circuit in at least two receiving circuits to select one of the filters to be connected to the processing circuit, so that the strong carrier signal and other carrier signals in the multi-carrier signal are filtered through different filters respectively, and the strong carrier signal is a carrier signal whose signal strength is greater than a preset signal strength. In the above manner, the present application can improve the dynamic range of the receiver.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a multi-carrier receiving method and a multi-carrier receiver. Background Art

[0002] Wideband multi-carrier receivers have great advantages in circuit miniaturization, cost control, and intermediate frequency planning. However, they are limited by the signal-to-noise ratio (SNR) and spurious free dynamic range (SFDR) specifications of the analog-to-digital converter (ADC). The dynamic range of the receiver is much lower than that of the superheterodyne receiver and is easily affected by in-band interference signals. Summary of the invention

[0003] The present application provides a multi-carrier receiving method and a multi-carrier receiver, which can improve the dynamic range of the receiver.

[0004] In order to solve the above technical problems, the technical solution adopted in the present application is: to provide a multi-carrier receiver, which includes: a signal processing circuit and multiple receiving circuits, each receiving circuit includes a processing circuit and a filter switching circuit connected to each other, the processing circuit is used to down-convert the multi-carrier signal to obtain an intermediate frequency signal; the filter switching circuit includes a selection circuit and multiple filters, the filter bandwidths of the multiple filters are different, and the selection circuit is used to select one of the filters from the multiple filters to filter the intermediate frequency signal to obtain a filtered signal; the signal processing circuit is respectively connected to each receiving circuit, and is used to detect whether there is a strong carrier signal in the multi-carrier signal, and when there is a strong carrier signal in the multi-carrier signal, control the selection circuits in at least two receiving circuits to select one of the filters to be connected to the processing circuit, so that the strong carrier signal and other carrier signals in the multi-carrier signal are filtered through different filters respectively, wherein the strong carrier signal is a carrier signal with a signal strength greater than a preset signal strength.

[0005] To solve the above technical problems, another technical solution adopted by the present application is: to provide a multi-carrier receiving method, which is applied to a multi-carrier receiver, the multi-carrier receiver includes a signal processing circuit and a plurality of receiving circuits respectively connected to the signal processing circuit, each receiving circuit includes a processing circuit and a filter switching circuit connected to each other, the filter switching circuit includes a selection circuit and a plurality of filters, and the filtering bandwidths of the plurality of filters are different. The method includes: using the processing circuit to down-convert the multi-carrier signal to obtain an intermediate frequency signal; using the selection circuit to select one of the filters from the plurality of filters to filter the intermediate frequency signal to obtain a filtered signal; using the signal processing circuit to detect whether there is a strong carrier signal in the multi-carrier signal, and when there is a strong carrier signal in the multi-carrier signal, controlling the selection circuits in at least two receiving circuits to select one of the filters to be connected to the processing circuit, so that the strong carrier signal and other carrier signals in the multi-carrier signal enter different filters respectively, wherein the strong carrier signal is a carrier signal having a signal strength greater than a preset signal strength.

[0006] Through the above scheme, the beneficial effects of the present application are: the multi-carrier receiver includes a signal processing circuit and multiple receiving circuits, each receiving circuit includes a processing circuit and a filter switching circuit, the processing circuit down-converts the multi-carrier signal to obtain a corresponding intermediate frequency signal; the filter switching circuit includes a selection circuit and multiple filters with different filter bandwidths, the selection circuit selects a filter from all filters, so that the filter filters the intermediate frequency signal to obtain a filtered signal; when there is a strong carrier signal with a signal strength greater than a preset signal strength in the multi-carrier signal, the signal processing circuit controls the selection circuits in at least two receiving circuits, so that the selection circuit selects the corresponding filter to be connected to the processing circuit, thereby allowing the strong carrier signal and other carrier signals in the multi-carrier signal to enter different filters respectively; since multiple filters with different filter bandwidths are designed on each receiving path, a suitable filter is selected to filter the intermediate frequency signal, which can suppress signals outside the passband of the filter, reduce the influence of interference signals, and improve the dynamic range of the receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0008] Figure 1 It is a structural diagram of an embodiment of a multi-carrier receiver provided by the present application;

[0009] Figure 2is a structural schematic diagram of an embodiment of a receiving circuit provided by the present application;

[0010] Figure 3 is a structural diagram of another embodiment of a multi-carrier receiver provided by the present application;

[0011] Figure 4 It is a structural schematic diagram of a processing circuit, a filtering switching circuit, and a signal processing circuit provided by the present application;

[0012] Figure 5 It is a schematic diagram of the frequency and signal strength of the four carrier signals provided in this application;

[0013] Figure 6 Yes Figure 5 Schematic diagram of demodulating the four carrier signals shown;

[0014] Figure 7 is another schematic diagram of the frequencies and signal strengths of the four carrier signals provided in this application;

[0015] Figure 8 Yes Figure 5 Another schematic diagram of demodulating the four carrier signals shown;

[0016] Fig. 9 Yes Figure 5 Another schematic diagram of demodulating the four carrier signals shown;

[0017] Fig.10 It is a flowchart of an embodiment of a multi-carrier receiving method provided by the present application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] Taking the 350MHz all-in-one device as an example, although its in-band blocking index can meet the industry requirement of 84dB, due to the large transmission power of the walkie-talkie, when talking at close range, the input level of the base station receiver is much higher than -23dBm, and in extreme cases the signal strength is greater than 0dBm. When a strong signal is received, for example: the power of one carrier signal f1 is -120dBm, and the power of another carrier signal f2 is -10dBm, the link gain is reduced due to the influence of the carrier signal f2 with a larger signal strength, resulting in the ADC being unable to demodulate the low-power carrier signal f1 of -120dBm.

[0020] In order to demodulate a low-power signal in the presence of a strong signal and improve the dynamic range of a multi-carrier receiver, the present application provides a new solution, which is described in detail below.

[0021] See also Figure 1 and Figure 2 , Figure 1 is a schematic structural diagram of an embodiment of a multi-carrier receiver provided by the present application, Figure 2 It is a structural diagram of an embodiment of a receiving circuit provided in the present application. The multi-carrier receiver includes: a plurality of receiving circuits 10 and a signal processing circuit 20. Each receiving circuit 10 includes a processing circuit 11 and a filter switching circuit 12 that are connected to each other.

[0022] The processing circuit 11 is used to obtain a carrier signal and down-convert the multi-carrier signal to obtain an intermediate frequency signal; specifically, the multi-carrier signal includes multiple carrier signals, the frequency difference between the multiple carrier signals can be a fixed value, the carrier signal is a radio frequency signal, and the processing circuit 11 can mix the radio frequency signal to achieve down-conversion.

[0023] The filter switching circuit 12 includes a selection circuit 122 and multiple filters 121. The filter bandwidths of the multiple filters 121 are different. The selection circuit 122 is used to select one of the filters 121 from the multiple filters 121 to filter the intermediate frequency signal to obtain a filtered signal; specifically, the bandwidth of the filter 121 with the widest bandwidth among the multiple filters 121 is greater than the signal bandwidth of the multi-carrier signal. The filter 121 can be a bandpass filter (BPF). Each filter 121 is connected to the selection circuit 122. Different filter bandwidths can be selected for the multiple filters 121 according to needs or the frequency of the carrier signal. For example: the number of carrier signals is 2, and 2 filters 121 are set in each filter switching circuit 12, and their filter bandwidths are: 500KHz, 2MHz; or the number of carrier signals is greater than 2, and the frequency interval between two adjacent carrier signals is 250KHz, then the frequency interval between the highest frequency carrier signal and the lowest frequency carrier signal is the product of the frequency interval between the two adjacent carrier signals and the number of carrier signals. At this time, 3 filters 121 can be set in each filter switching circuit 12, record As F1, F2 and F3, the bandwidth of filter F1 is less than the frequency interval of two adjacent carrier signals, that is, less than 250KHz, the bandwidth of filter F2 is greater than the frequency interval of two adjacent carrier signals and less than / equal to the frequency interval between the highest frequency carrier signal and the lowest frequency carrier signal, the bandwidth of filter F3 is the largest and greater than the signal bandwidth of the multi-carrier signal, for example: the number of carrier signals is 4, the filtering bandwidths of filters F1-F3 can be set to: 100KHz, 1MHz and 5MHz, respectively. Of course, the bandwidth of filter 121 is shown here only as an example and is not used to limit the present application. The specific values ​​of the bandwidths of each filter 121 can be set according to specific application requirements.

[0024] Further, in the initial state, a filter 121 in the filter switching circuit 12 may be connected to the processing circuit 11 and the signal processing circuit 20 by default through the selection circuit 122. For example, assuming that the receiving circuit 10 includes 4 filters 121, the fourth filter 121 is connected to the processing circuit 11 and the signal processing circuit 20 by default. It can be understood that the number of filters 121 in each receiving circuit 10 or the filter 121 connected by default may be different; for example, in the first receiving circuit 10, the second filter 121 is connected to the processing circuit 11 and the signal processing circuit 20 by default; in the second receiving circuit 10, the third filter 121 is connected to the processing circuit 11 and the signal processing circuit 20 by default. Here, it should be noted that the filter 121 connected by default is a filter with a wider bandwidth, and the filtering bandwidth of the filter with a wider bandwidth is greater than the frequency interval between the highest frequency carrier signal and the lowest frequency carrier signal; for example, taking the number of carrier signals as 4 and the frequency interval of the carrier signals as 250KHz as an example, the bandwidth of the filter with a wider bandwidth may be 1MHz.

[0025] The signal processing circuit 20 is connected to each receiving circuit 10 respectively, and is used to detect whether there is a strong carrier signal in the multi-carrier signal, and when there is a strong carrier signal in the multi-filter signal, control the selection circuit 122 in at least two receiving circuits 10 to select one of the filters 121 to be connected to the processing circuit 11, so that the strong carrier signal and other carrier signals in the multi-carrier signal are filtered through different filters 121 respectively, and the other carrier signals are carrier signals in the multi-carrier signal except the strong carrier signal. The strong carrier signal is a carrier signal whose signal strength is greater than a preset signal strength. The preset signal strength can be a signal strength threshold set according to experience or application needs, such as: -30dBm. Specifically, the detection of the signal strength of the multi-carrier signal is essentially the detection of the signal strength of the filtered signal output by the receiving circuit 10, that is, after receiving the filtered signal output by the receiving circuit 10, the signal processing circuit 20 detects the signal strength of the filtered signal and compares the signal strength of the filtered signal with the preset signal strength. If it is determined that the signal strength of the filtered signal is greater than the preset signal strength, it indicates that there is a signal with a larger signal strength among the multiple received carrier signals. In order to reduce the influence of this strong signal on other carrier signals, the signal processing circuit 20 generates a control signal and sends the control signal to the filter switching circuit 12 to switch the filter 121 in the filter switching circuit 12 that filters the intermediate frequency signal.

[0026] Furthermore, when detecting whether there is a strong carrier signal in a multi-carrier signal, a suitable filter 121 can be selected based on the frequency interval between the highest frequency of the carrier signal and the lowest frequency of the carrier signal. For example, assuming that the frequency interval between the highest frequency and the lowest frequency is about 1 MHz, a filter 121 with a filtering bandwidth of 1 MHz can be used to filter the multi-carrier signal.

[0027] In the existing intermediate frequency receiving circuit design, the filter in the intermediate frequency receiving circuit is a broadband filter, which has no inhibitory effect on useful or interfering signals in the band. The solution provided in this embodiment designs multiple filters with different filtering bandwidths on the intermediate frequency receiving path, and selects a suitable filter to filter the intermediate frequency signal according to the signal strength of the carrier signal in the multi-carrier signal and the bandwidth of the carrier signal, which has a certain inhibitory effect (more than 30dB) on the signal outside the passband of the filter, reduces the influence of the interference signal, and can improve the dynamic range of the receiver, better meet the application scenarios such as vehicle-mounted or portable, and improve the applicability of the product.

[0028] See also Figure 3 , Figure 3 1 is a schematic diagram of the structure of another embodiment of a multi-carrier receiver provided in the present application. The multi-carrier receiver includes: a plurality of receiving circuits 10, a signal processing circuit 20 and an antenna 30.

[0029] The antenna 30 is connected to the plurality of receiving circuits 10 respectively, and is used to transmit the received multi-carrier signal to the plurality of receiving circuits 10 .

[0030] Each receiving circuit 10 is connected to the antenna 30 , and includes a processing circuit 11 , a filter switching circuit 12 and an ADC 13 .

[0031] The processing circuit 11 is used to down-convert the multi-carrier signal to obtain an intermediate frequency signal. Figure 4As shown, the processing circuit 11 includes: a first amplifier 111, a digital step attenuator (DSA) 112, a fourth filter 113, a second amplifier 114, a fifth filter 115, a local oscillator 116 and a mixer 117. The first amplifier 111 is connected to the antenna 30, which can be a low noise amplifier (LNA) for amplifying the carrier signal; the DSA 112 attenuates the carrier signal output by the first amplifier 111; the fourth filter 113 filters the carrier signal output by the DSA 112; the second amplifier 114 amplifies the carrier signal output by the fourth filter 113; the fifth filter 115 filters the carrier signal output by the second amplifier 114; the local oscillator 116 is used to generate a local oscillation signal; the mixer 117 is used to mix the local oscillation signal with the carrier signal output by the fifth filter 115 to obtain an intermediate frequency signal.

[0032] In other embodiments, the local oscillator 116 may also be shared by multiple receiving circuits 10, that is, the local oscillator 116 is connected to the mixer 117 in each processing circuit 11, so that one local oscillator 116 is used to generate a local oscillation signal, which helps to reduce the overall size of the circuit and reduce costs.

[0033] The filter switching circuit 12 includes a plurality of filters 121 with different filter bandwidths and a selection circuit 122 . The selection circuit 122 includes a first selection circuit 1221 and a second selection circuit 1222 .

[0034] The first selection circuit 1221 is connected to the processing circuit 11 and the signal processing circuit 20. After receiving the first control signal output by the signal processing circuit 20, it is used to select the filter 121 corresponding to the first control signal and transmit the intermediate frequency signal to the filter 121, so that the filter 121 filters the intermediate frequency signal to obtain a filtered signal.

[0035] The second selection circuit 1222 is connected to the signal processing circuit 20, and is used to select the filter 121 corresponding to the first control signal to be connected to the signal processing circuit 20 after receiving the second control signal output by the signal processing circuit 20, that is, the filter 121 selected by the first selection circuit 1221 is the same as the filter 121 selected by the second selection circuit 1222, so as to transmit the filtered signal filtered by the filter 121 to the signal processing circuit 20.

[0036] Furthermore, if Figure 4As shown, the first selection circuit 1221 is a first single-pole multi-throw switch, which includes a first input terminal and a plurality of first output terminals (not marked in the figure), the first input terminal is connected to the processing circuit 11, and the plurality of first output terminals are respectively connected to the filter 121, that is, the plurality of first output terminals correspond one-to-one with the plurality of filters 121; the second selection circuit 1222 is a second single-pole multi-throw switch, which includes a plurality of second input terminals and a second output terminal (not marked in the figure), the plurality of second input terminals are respectively connected to the filter 121, that is, the plurality of second input terminals correspond one-to-one with the plurality of filters 121, and the second output terminal is connected to the signal processing circuit 20. It can be understood that Figure 4 An example is taken in which the number of filters 121 is 3, but the present invention is not limited thereto, and the number of filters 121 may be set according to specific needs.

[0037] The ADC 13 is used to perform analog-to-digital conversion on the filtered signal to obtain a digital signal, which is a digital intermediate frequency signal.

[0038] In other embodiments, Figure 4 As shown, the receiving circuit 10 also includes a third amplifier 14 and a sixth filter 15 arranged between the filter switching circuit 12 and the ADC 13. The third amplifier 14 can be a variable gain amplifier (VGA) to amplify the filtered signal; the sixth filter 15 can be a BPF to filter the filtered signal output by the VGA and filter out interference signals.

[0039] The signal processing circuit 20 is connected to the receiving circuit 10, and is used to detect the signal strength of the carrier signal. When the signal strength of the carrier signal is greater than the preset signal strength, the control processing circuit 11 is connected to the corresponding filter 121, so that the strong carrier signal and other carrier signals in the multi-carrier signal are filtered by different filters 121 respectively. Specifically, the signal processing circuit 20 is a digital processing chip, such as Figure 4 As shown, the digital processing chip is connected to the ADC 13 and the selection circuit 122, and the digital processing chip is used to identify the signal strength of the digital signal.

[0040] The signal processing circuit 20 is also used to determine whether the frequency of the strong carrier signal is the minimum value or the maximum value of the frequency of the carrier signal in the multi-carrier signal, obtain the determination result and control the filter switching circuit 12 based on the determination result.

[0041] Furthermore, the signal processing circuit 20 is used to control the selection circuit 122 in one of the receiving circuits 10 to select the filter 121 with the widest bandwidth from multiple filters 121 and connect it to the processing circuit 11 to obtain a filtered signal corresponding to the strong carrier signal when the judgment result is that the frequency of the strong carrier signal is the minimum value or maximum value of the frequency of the carrier signal in the multi-carrier signal, and to control the selection circuit 122 in another receiving circuit 10 to select the filter 121 that matches the bandwidth of other carrier signals in the multi-carrier signal from multiple filters 121 and connect it to the processing circuit 11 to obtain filtered signals corresponding to other carrier signals in the multi-carrier signal.

[0042] In a specific embodiment, the plurality of receiving circuits 10 include a first receiving circuit and a second receiving circuit (not shown in the figure), and the plurality of filters 121 with different filtering bandwidths include a first filter and a second filter (not shown in the figure), and the filtering bandwidth of the first filter is greater than the filtering bandwidth of the second filter; the first receiving circuit is used to demodulate the strong carrier signal, and the signal processing circuit 20 is used to control the processing circuit 11 in the first receiving circuit to be connected to the first filter in the first receiving circuit; the second receiving circuit is used to demodulate at least part of the carrier signal except the strong carrier signal, and the signal processing circuit 20 is used to control the processing circuit 11 in the second receiving circuit to be connected to the second filter in the second receiving circuit. In another specific embodiment, the plurality of receiving circuits 10 also include a third receiving circuit (not shown in the figure), and the plurality of filters 121 with different filtering bandwidths also include a third filter (not shown in the figure), and the filtering bandwidth of the second filter is greater than the filtering bandwidth of the third filter, and the carrier signal with a frequency greater than the frequency of the strong carrier signal in the multi-carrier signal is recorded as the first carrier signal, and the carrier signal with a frequency less than the frequency of the strong carrier signal in the multi-carrier signal is recorded as the second carrier signal. The signal processing circuit 20 is also used to control the selection circuit 122 in one of the receiving circuits 10 (i.e., the first receiving circuit) to select a filter 121 that matches the bandwidth of the first carrier signal from the second filter and the third filter to connect to the processing circuit 11 to obtain a filtered signal corresponding to the first carrier signal when the frequency of the strong carrier signal is not the minimum value or the maximum value of the frequency of the carrier signal in the multi-carrier signal, and to control the selection circuit 122 in another of the receiving circuits 10 (i.e., the second receiving circuit) to select the first filter to connect to the processing circuit 11 to obtain a filtered signal corresponding to the strong carrier signal, and to control the selection circuit 122 in yet another of the receiving circuits 10 (i.e., the third receiving circuit) to select a filter 121 that matches the bandwidth of the second carrier signal from the first filter and the second filter to connect to the processing circuit 11 to obtain a filtered signal corresponding to the second carrier signal.

[0043] In other specific embodiments, the signal processing circuit 20 is also used to control the selection circuit 122 in one of the receiving circuits 10 to select a filter with the widest bandwidth from multiple filters and connect it to the processing circuit 11 to obtain a filtered signal corresponding to the multi-carrier signal when there is no strong carrier signal in the multi-carrier signal.

[0044] It can be understood that the number of receiving circuits 10 is determined by the number of carrier signals and the number of demodulated signals that need to be obtained. For example, if the number of carrier signals is greater than 3, then the number of receiving circuits 10 is at least 3 and less than or equal to the number of carrier signals. If it is only for separating strong signals from other carrier signals, the number of demodulated signals is at most 3, and only 3 receiving circuits 10 can be set at this time. If it is to demodulate strong signals and carrier signals of different frequency bands in other carrier signals or each carrier signal in other carrier signals separately, more receiving circuits 10 need to be set to obtain the corresponding number of demodulated signals.

[0045] In other specific embodiments, the multiple receiving circuits 10 also include a fourth receiving circuit (not shown in the figure), which is connected to the signal processing circuit 20, and is used to scan and monitor whether there is a strong carrier signal, and feed it back to the processing circuit 20. The working principles of the first to fourth receiving circuits are described in detail below.

[0046] In a specific implementation, a four-carrier base station with a carrier signal frequency interval of 250KHz is taken as an example, that is, the multi-carrier signal includes 4 carrier signals, and the frequency interval of two adjacent carrier signals is 250KHz. Assuming that a strong signal appears at a certain moment on the receiving side, there are a total of Figure 5 In the four signal combinations shown, the filtering bandwidth of the first filter is 5MHz, the filtering bandwidth of the second filter is 1MHz, and the filtering bandwidth of the third filter is 150KHz. In order to simplify the description of the signal receiving process, combination 1 and combination 4 can be classified into the same category (combination A), and combination 2 and combination 3 can be classified into the same category (combination B).

[0047] In the initial state, the first to fourth receiving circuits all select the second filter to be connected to the processing circuit 11 and the signal processing circuit 20 through the selection circuit 122, that is, a filter with a wider bandwidth (i.e., the second filter) is selected for filtering. The multi-carrier signal is received by the four-way receiving circuit and the second filter can ensure the integrity of the received carrier signal; then, the signal strength of the carrier signal is detected by the signal processing circuit 20 and it is determined whether to switch the filters in the first to third receiving circuits according to the signal strength of the carrier signal. The specific processing process is described as follows.

[0048] (1) Normal reception mode when there is no strong signal

[0049] Figure 6 As shown, Figure 6 Yes Figure 3 The simplification eliminates the need for Figure 3 In addition to the other circuit elements of the filter and the signal processing circuit, the RXD2 receiving channel where the fourth receiving circuit (not marked in the figure) is located is used to scan and monitor whether there is a strong carrier signal, and the second filter is used for filtering, that is, a filter with a wider bandwidth is used, so that all carrier signals can pass; when there is no strong carrier signal, for example, Figure 7 As shown, the signal strengths corresponding to the carrier signals f1-f4 are all less than the preset signal strengths; the four carrier signals are demodulated in the normal receiving mode, and the carrier signals are demodulated via the RX-Main receiving channel where the first receiving circuit is located, and filtered using the first filter to ensure that more carrier signals pass through, thereby improving the sensitivity of the receiver.

[0050] (2) Combination A receiving mode

[0051] Figure 8 As shown, the RXD2 receiving channel where the fourth receiving circuit is located is used to scan and monitor whether there is a strong carrier signal, and the second filter is used for filtering; Figure 5 Taking the combination 1 shown as an example, when a strong carrier signal appears, the four carrier signals are demodulated by different receiving channels respectively, the strong carrier signal f1 enters the RX Main receiving channel where the first receiving circuit is located for demodulation, and the first filter is selected. The carrier signals f2-f4 are demodulated through the RXD0 receiving channel where the second receiving circuit is located, and are filtered using the second filter to ensure that the carrier signals f2-f4 can all pass.

[0052] (3) Combination B receiving mode

[0053] Fig. 9 As shown, the RXD2 receiving channel where the fourth receiving circuit is located is used to scan and monitor whether there is a strong carrier signal, and the second filter is used for filtering; Figure 5 Taking the combination 2 shown as an example, when a strong carrier signal appears, the four carrier signals are demodulated by different receiving channels respectively. The normal carrier signal f1 enters the RX Main receiving channel where the first receiving circuit is located for demodulation, and is filtered using the third filter to filter out other carrier signals and reduce interference; the strong carrier signal f2 enters the RXD0 receiving channel where the second receiving circuit is located for processing, and is filtered using the first filter; the normal carrier signals f3-f4 enter the RXD1 receiving channel where the third receiving circuit is located for demodulation, and are filtered using the second filter to ensure that the carrier signals f3-f4 can all pass.

[0054] The technical solution provided in this embodiment can improve product performance, increase the dynamic range of the receiver, and solve the problem of near-far effect existing in multi-carrier receivers, so that in application scenarios such as vehicle-mounted and portable all-in-one receivers, the blocking sensitivity will not be reduced due to strong signals, and the problems of dropped characters or no voice in remote handset calls can be avoided.

[0055] See also Fig.10 , Fig.10 1 is a flow chart of an embodiment of a multi-carrier receiving method provided by the present application. The method is applied to the multi-carrier receiver in the above embodiment. The multi-carrier receiver includes a signal processing circuit and a plurality of receiving circuits respectively connected to the signal processing circuit. Each receiving circuit includes a processing circuit and a filter switching circuit connected to each other. The filter switching circuit includes a selection circuit and a plurality of filters. The filter bandwidths of the plurality of filters are different. The method includes:

[0056] Step 101: down-convert the multi-carrier signal using a processing circuit to obtain an intermediate frequency signal.

[0057] Step 102: Using a selection circuit, select one of the filters from a plurality of filters to filter the intermediate frequency signal.

[0058] Preferably, in the initial state, the first to fourth receiving circuits all select the second filter to be connected to the processing circuit and the signal processing circuit through the selection circuit, that is, a filter with a wider bandwidth is selected for filtering. Receiving multi-carrier signals through four-way receiving circuits and selecting a filter with a wider bandwidth can ensure the integrity of the received carrier signal.

[0059] Step 103: Detect the carrier signal with the strongest signal strength in the multi-filtered signals using a signal processing circuit, and record it as a strong carrier signal.

[0060] Step 104: When there is a strong carrier signal in the multi-carrier signal, control the selection circuits in at least two receiving circuits to select one of the filters to be connected to the processing circuit, so that the strong carrier signal and other carrier signals in the multi-carrier signal are filtered through different filters respectively.

[0061] A strong carrier signal is a carrier signal with a signal strength greater than a preset signal strength. The structure and working principle of the multi-carrier receiver are the same as those of the above multi-carrier receiver embodiment, and will not be described in detail here.

[0062] This embodiment provides a method for improving the dynamic range of a broadband receiver. In the intermediate frequency receiving path of a multi-carrier receiver, multiple filter channels with different filter bandwidths are designed. According to the frequency difference between the highest frequency of the carrier signal and the lowest frequency of the carrier signal, a suitable filter channel is selected to process the carrier signal, thereby suppressing the signal outside the filter passband, thereby improving the receiver dynamic range and in-band blocking index. The method can be applied to a transceiver or a multi-carrier receiver in a communication system.

[0063] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A multi-carrier receiver, characterized in that: include: A plurality of receiving circuits, each of which comprises a processing circuit and a filter switching circuit connected to each other, wherein the processing circuit is used to down-convert a multi-carrier signal to obtain an intermediate frequency signal; the filter switching circuit comprises a selection circuit and a plurality of filters, wherein the filter bandwidths of the plurality of filters are different, and the selection circuit is used to select one of the plurality of filters to filter the intermediate frequency signal; A signal processing circuit is connected to each of the receiving circuits, and is used to detect whether there is a strong carrier signal in the multi-carrier signal, and when there is a strong carrier signal in the multi-carrier signal, control the selection circuits in at least two receiving circuits to select one of the filters to be connected to the processing circuit, so that the strong carrier signal and other carrier signals in the multi-carrier signal are filtered through different filters respectively, wherein the strong carrier signal is a carrier signal with a signal strength greater than a preset signal strength; among all the carrier signals, a carrier signal with a frequency greater than the frequency of the strong carrier signal is a first carrier signal, and a carrier signal with a frequency less than the frequency of the strong carrier signal is a second carrier signal, and the signal processing circuit is used to determine whether the frequency of the strong carrier signal is the frequency of the carrier signal in the multi-carrier signal. The method is used to control a selection circuit in one of the receiving circuits to select a filter matching the bandwidth of the first carrier signal from the multiple filters to connect to the processing circuit to obtain a filtered signal corresponding to the first carrier signal when the frequency of the strong carrier signal is not the minimum value or maximum value of the frequency of the carrier signal in the multi-carrier signal, and to control a selection circuit in one of the receiving circuits to select a filter matching the bandwidth of the first carrier signal from the multiple filters to connect to the processing circuit to obtain a filtered signal corresponding to the first carrier signal, and to control a selection circuit in another of the receiving circuits to select a filter matching the bandwidth of the second carrier signal from the multiple filters to connect to the processing circuit to obtain a filtered signal corresponding to the second carrier signal.

2. The multi-carrier receiver according to claim 1, characterized in that: The selection circuit comprises: A first selection circuit is connected to the processing circuit and the signal processing circuit, and is used for selecting a filter corresponding to the first control signal to be connected to the processing circuit after receiving a first control signal output by the signal processing circuit, so as to transmit the intermediate frequency signal to the filter; A second selection circuit is connected to the signal processing circuit and is used to select a filter corresponding to the first control signal and connect it to the signal processing circuit after receiving a second control signal output by the signal processing circuit, so as to transmit the filtered signal after filtering by the filter to the signal processing circuit.

3. The multi-carrier receiver according to claim 2, characterized in that: The first selection circuit is a first single-pole multi-throw switch, which includes a first input terminal and multiple first output terminals, the first input terminal is connected to the processing circuit, and the multiple first output terminals are respectively connected to the filter; the second selection circuit is a second single-pole multi-throw switch, which includes multiple second input terminals and second output terminals, the multiple second input terminals are respectively connected to the filter, and the second output terminal is connected to the signal processing circuit.

4. The multi-carrier receiver according to claim 1, characterized in that: The signal processing circuit is also used to control the selection circuit in one of the receiving circuits to select a filter with the widest bandwidth from the multiple filters to connect to the processing circuit to obtain a filtered signal corresponding to the strong carrier signal when the frequency of the strong carrier signal is the minimum value or the maximum value of the frequency of the carrier signal in the multi-carrier signal, and to control the selection circuit in another of the receiving circuits to select a filter that matches the bandwidth of other carrier signals in the multi-carrier signal from the multiple filters to connect to the processing circuit to obtain filtered signals corresponding to other carrier signals in the multi-carrier signal.

5. The multi-carrier receiver according to claim 1, characterized in that: The signal processing circuit is also used to control a selection circuit in one of the receiving circuits to select a filter with the widest bandwidth from the multiple filters and connect it to a processing circuit to obtain a filtered signal corresponding to the multi-carrier signal when there is no strong carrier signal in the multi-carrier signal.

6. The multi-carrier receiver according to any one of claims 1 to 5, characterized in that: The bandwidth of the filter with the widest bandwidth among the plurality of filters is greater than the signal bandwidth of the multi-carrier signal.

7. The multi-carrier receiver according to claim 1, characterized in that: The receiving circuit also includes an analog-to-digital converter, the signal processing circuit is a digital processing chip, the digital processing chip is connected to the analog-to-digital converter and the selection circuit, and the analog-to-digital converter is used to perform analog-to-digital conversion on the filtered signal to obtain a digital signal.

8. The multi-carrier receiver according to claim 1, characterized in that: The multi-carrier receiver further includes an antenna, which is connected to the multiple receiving circuits respectively and is used to transmit the received multi-carrier signal to the multiple receiving circuits.

9. A multi-carrier receiving method, characterized in that: Applied to a multi-carrier receiver, the multi-carrier receiver comprises a signal processing circuit and a plurality of receiving circuits respectively connected to the signal processing circuit, each of the receiving circuits comprises a processing circuit and a filter switching circuit connected to each other, the filter switching circuit comprises a selection circuit and a plurality of filters, the filter bandwidths of the plurality of filters are different, the method comprises: Down-converting the multi-carrier signal using the processing circuit to obtain an intermediate frequency signal; Selecting one of the filters from the plurality of filters by using the selection circuit to filter the intermediate frequency signal; Utilizing the signal processing circuit to detect whether there is a strong carrier signal in the multi-carrier signal, and when there is a strong carrier signal in the multi-carrier signal, controlling the selection circuits in at least two receiving circuits to select one of the filters to be connected to the processing circuit, so that the strong carrier signal and other carrier signals in the multi-carrier signal are filtered through different filters respectively, wherein the strong carrier signal is a carrier signal having a signal strength greater than a preset signal strength; The control of the selection circuit in at least two receiving circuits to select one of the filters to be connected to the processing circuit so that the strong carrier signal and other carrier signals in the multi-carrier signal are filtered through different filters respectively, includes: judging whether the frequency of the strong carrier signal is the minimum value or the maximum value of the frequency of the carrier signal in the multi-carrier signal, and when the frequency of the strong carrier signal is not the minimum value or the maximum value of the frequency of the carrier signal in the multi-carrier signal, controlling the selection circuit in one of the receiving circuits to select a filter matching the bandwidth of the first carrier signal from the multiple filters to be connected to the processing circuit to obtain a filtered signal corresponding to the first carrier signal, and controlling the selection circuit in another receiving circuit to select a filter matching the bandwidth of the second carrier signal from the multiple filters to be connected to the processing circuit to obtain a filtered signal corresponding to the second carrier signal; wherein the first carrier signal is a carrier signal having a frequency greater than the frequency of the strong carrier signal among all the carrier signals, and the second carrier signal is a carrier signal having a frequency less than the frequency of the strong carrier signal among all the carrier signals.

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