Interference elimination device suitable for broadband receiver

Abstract

The invention relates to an interference elimination device suitable for a broadband receiver, and belongs to the technical field of wireless communication. The device comprises a first power divider, a second power divider, a filter, an analog-to-digital converter (ADC), a signal processing unit, a digital-to-analog converter (DAC) and a combiner. The first power divider divides a broadband radio frequency signal into a reference signal and a pre-cancellation receiving signal. A reference signal is divided into multiple paths of narrow-band radio-frequency signals, the narrow-band radio-frequency signals are converted into digital signals through an ADC and then sent to a signal processing unit, and interference signal components are detected. The signal processing unit generates a corresponding digital anti-phase offset signal, and the digital anti-phase offset signal is converted into a radio frequency offset signal through the DAC. And the radio frequency offset signal is sent to the combiner to be combined with the pre-elimination receiving signal. Interference components contained in the pre-elimination receiving signal are added and counteracted by the counteracting signal, and a counteracted useful signal is obtained. The device carries out adaptive interference cancellation on the radio frequency signal received by the broadband receiver, prevents the broadband receiver from being blocked by in-band interference, and enables the broadband receiver to obtain a larger dynamic range.

Description

Technical Field

[0001] The invention relates to an interference elimination device suitable for a broadband receiver, belonging to the technical field of wireless communications. Background Art

[0002] Currently, analog-to-digital converters (ADCs) can provide increasingly higher instantaneous bandwidths, enabling them to be used in wideband digital receivers in the field of wireless communications. Since the input voltage range of high-speed ADCs is relatively small, if the signal input to the high-speed ADC contains interference components, the available dynamic range will be further reduced. In severe cases, it may even cause ADC input saturation, making the wideband digital receiver unable to work properly. Therefore, compared with traditional narrowband receivers, wideband digital receivers are more susceptible to in-band interference. In addition, since the interference frequency and interference amount in the wideband signal are often not fixed, it is difficult to use a specific filter to filter out the interference. Summary of the invention

[0003] The purpose of the present invention is to solve the technical problem that in-band interference in broadband radio frequency signals easily causes saturation of a broadband digital receiver ADC, resulting in malfunction, and creatively proposes an interference elimination device suitable for a broadband receiver.

[0004] The device of the present invention belongs to an active interference elimination device, which can perform adaptive interference cancellation on the radio frequency signal received by the broadband receiver, avoid the broadband receiver being blocked by in-band interference, and enable the broadband receiver to obtain a larger dynamic range.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] An interference elimination device suitable for a broadband receiver comprises a first power divider, a second power divider, a filter, an analog-to-digital converter ADC, a signal processing unit, a digital-to-analog converter DAC, and a combiner.

[0007] Among them, the filter is composed of multiple narrow-band bandpass filters with different frequency bands, which can cover the entire broadband signal.

[0008] The device receives external broadband radio frequency signals through a receiving antenna.

[0009] The first power divider divides the received broadband radio frequency signal into two paths, one path is used as a reference signal for generating a cancellation signal, and the other path is used as a pre-elimination receiving signal.

[0010] The second power divider divides the reference signal into multiple paths and sends them to the input ends of the filters respectively.

[0011] Each filter converts a broadband RF signal into a narrowband RF signal and sends it to the corresponding ADC; each filter is configured with an ADC;

[0012] The ADC converts the narrowband RF signal into a digital signal and sends it to the signal processing unit;

[0013] The signal processing unit processes the digital signal, generates a digital signal that is inverted with the interference signal, and sends it to the DAC;

[0014] The DAC converts the digital signal that is in phase with the interference signal into a radio frequency cancellation signal that is in phase with the interference signal and sends it to the combiner;

[0015] The combiner adds the RF cancellation signal to the pre-cancellation receiving signal, and the interference signal contained in the pre-cancellation receiving signal is reversely canceled to obtain the receiving signal after interference cancellation.

[0016] Beneficial Effects

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The device of the present invention divides a broadband radio frequency signal into multiple narrowband signals and sends them to an ADC for collection. The signals are detected by a signal processing unit and further generate an anti-phase cancellation signal. The interference components in the received signal are added to the received signal from the receiving antenna by a combiner, and the cancellation signal is added to cancel the interference components in the received signal, and only the useful signal is output, which effectively avoids the saturation problem of the ADC of the subsequent broadband digital receiver caused by the in-band interference, and improves the dynamic range of the receiver in the presence of in-band interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the device of the present invention;

[0020] Among them, 100 is a receiving antenna, 200 is an interference elimination device, 201 is a first power divider, 202 is a second power divider, 203 is a filter, 204 is an ADC, 205 is a signal processing unit, 206 is a DAC, and 207 is a combiner. DETAILED DESCRIPTION

[0021] The invention is further described below with reference to the accompanying drawings and examples.

[0022] Example

[0023] like Figure 1 As shown, an interference elimination device 200 suitable for a broadband receiver includes a first power divider 201 , a second power divider 202 , a filter 203 , an ADC 204 , a signal processing unit 205 , a DAC 206 and a combiner 207 .

[0024] Among them, the input end of the first power divider 201 is connected to the receiving antenna 100. The output end of the first power divider 201 is respectively connected to the input end of the second power divider 202 and the input end of the combiner 207. The output end of the second power divider 202 is connected to the input end of each filter 203, the output end of the filter 203 is connected to the corresponding ADC 204 input end, and the output end of the ADC 204 is connected to the input end of the signal processing unit 205. The output end of the signal processing unit 205 is connected to the input end of the DAC 206. The output end of the DAC 206 is connected to the input end of the combiner 207. The output end of the combiner 207 is connected to an external receiver.

[0025] The working method of this device is as follows:

[0026] The first power divider 201 divides the broadband radio frequency signal received by the receiving antenna 100 into two paths, one path is used to generate a reference signal for canceling the signal, and the other path is used to pre-eliminate the received signal. The components of the two paths of signals are the same.

[0027] The reference signal is sent to the filter 203 after passing through the second power divider 202 and is divided into multiple narrowband RF signals. The multiple narrowband RF signals are converted into digital signals by ADC 204, and the digital signals are sent to the signal processing unit 205 for processing to detect the interference signal components. Then, the signal processing unit 205 generates a corresponding digital inverted cancellation signal, which is converted into a RF cancellation signal by DAC 206. The RF cancellation signal is sent to the combiner 207 and combined with the pre-elimination received signal. The interference components contained in the pre-elimination received signal are added and offset by the cancellation signal to obtain a useful signal after cancellation, which is sent to the receiver.

[0028] Furthermore, the broadband RF signal R(t) received by the receiving antenna 100 is divided into two paths, a reference signal and a pre-elimination receiving signal, through the first power divider 201. The two signal components are the same and are both denoted as r(t). Among them, r(t) contains a useful signal component u(t) and an interference signal component X(t), r(t) = u(t) + X(t). The reference signal r(t) is further divided into several signals r'(t) with the same components through the second power divider 202. r'(t) is filtered into a narrowband RF signal through filters 203 with different frequency bands and sent to ADC204. ADC204 converts the narrowband RF signal into a digital signal and sends it to the signal processing unit 205. The signal processing unit 205 detects the interference components of each narrowband signal, generates a corresponding digital inverted cancellation signal, and converts it into a RF cancellation signal c(t) through DAC206, that is: c(t) = -X(t).

[0029] The RF cancellation signal c(t) is combined with the pre-cancelled received signal r(t) in the combiner 207, and the interference-cancelled signal y(t) is obtained from the output end of the combiner 207:

[0030] y(t)=r(t)+c(t)=u(t)+X(t)-X(t)=u(t)

[0031] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An interference elimination device suitable for a broadband receiver, characterized in that: It comprises a first power divider (201), a second power divider (202), a filter (203), an ADC (204), a signal processing unit (205), a DAC (206) and a combiner (207); The input end of the first power divider (201) is connected to the receiving antenna 100; the output end of the first power divider (201) is respectively connected to the input end of the second power divider (202) and the input end of the combiner (207); the output end of the second power divider (202) is connected to the input end of each filter (203); the output end of the filter (203) is connected to the input end of the corresponding ADC (204); the output end of the ADC (204) is connected to the input end of the signal processing unit (205); the output end of the signal processing unit (205) is connected to the input end of the DAC (206); the output end of the DAC (206) is connected to the input end of the combiner (207); and the output end of the combiner (207) is connected to an external receiver; The filter (203) is composed of a plurality of narrow-band pass filters with different frequency bands, and these filters can cover the entire broadband signal; each filter converts the broadband radio frequency signal into a narrow-band radio frequency signal and sends it to the corresponding ADC; each filter is correspondingly configured with an ADC; The first power divider (201) divides the received broadband radio frequency signal into two paths, one path is used to generate a reference signal for a cancellation signal, and the other path is used as a pre-elimination reception signal, and the components of the two paths are the same; the reference signal is sent to the filter (203) after passing through the second power divider (202), and is divided into multiple narrow-band radio frequency signals; the multiple narrow-band radio frequency signals are converted into digital signals through the ADC (204), and the digital signals are sent to the signal processing unit (205) for processing to detect interference signal components; then, the signal processing unit (205) generates a corresponding digital anti-phase cancellation signal, which is converted into a radio frequency cancellation signal through the DAC (206); the radio frequency cancellation signal is sent to the combiner (207) and combined with the pre-elimination reception signal; the interference component contained in the pre-elimination reception signal is added and cancelled by the cancellation signal, and a useful signal after cancellation is obtained, which is sent to the receiver.

Images