CN104124986B - Wireless signal receiver and signal processing method thereof - Google Patents

Abstract

The invention provides a wireless signal receiver and a signal processing method thereof. The invention provides a wireless signal receiver which comprises a receiving module, an automatic gain control module, a measuring module, a decoding module and a control module. The receiving module is used for receiving a wireless signal. The automatic gain control module is used for adjusting the amplitude of the wireless signal according to a gain value so as to generate an adjusted signal. The measuring module is used for measuring the signal intensity of the adjusted signal. The decoding module is used for decoding the adjusted signal. When the decoding module determines that the adjusted signal corresponds to a beacon packet transmitted from a transmitting end, the control module adjusts the gain value according to the signal strength.

Description

Wireless signal receiver and signal processing method thereof

technical field

The present invention is related to wireless communication systems, and more particularly to automatic gain control (AGC) techniques in wireless signal receivers.

Background technique

A receiving end of a wireless local area network (wireless local area network, WLAN) system must have the ability to receive multiple signals with different intensities. In practice, the signal strength difference faced by the receiving end may be as high as 90dB. The automatic gain control (AGC) circuit at the front end of the receiving end is responsible for adjusting the amplitude of the input signal, so that the amplitude of the adjusted signal falls within the dynamic range of the subsequent analog-digital-converter. If the automatic gain control circuit does not work properly, the signal amplitude provided to the analog-to-digital-converter may be too large to cause saturation of the analog-to-digital-converter, or too small to cause the signal-to-noise ratio to be too low, thereby affecting the correctness of the decoding result sex.

In the current technology, the receiver stores a fixed initial gain value. Before starting to execute the packet search procedure each time, the gain value of the automatic gain control circuit is reset to the initial gain value. The automatic gain control circuit then starts from this initial gain value and dynamically adjusts its gain value according to the amplitude of the input signal. It can be understood that, if the difference between the gain value suitable for receiving a packet and the initial gain value is greater, the automatic gain control circuit generally needs more time to find a suitable gain value.

Most automatic gain control circuits must find the appropriate gain value within a certain time limit. Taking the 802.11a/g/n communication standard as an example, the time limit is eight microseconds (μs), which is the length of the short preamble of the packet. Generally speaking, the farther the distance between the transmitting end and the receiving end is, the weaker the strength of the signal received by the receiving end is. In fact, the distance between the receiving end (such as a laptop or a smart phone) and the transmitting end is not necessarily a constant value. In different occasions, the transmitting end providing the communication link is also different. A fixed initial gain value will obviously not work for a wide range of wireless signal strengths. If the difference between the initial gain value and the target gain value is too large, the automatic gain control circuit cannot find a suitable gain value in time, and the receiving end may miss the packet provided by the transmitting end (such as the wireless access device). In this case, the receiving end will request the transmitting end to send a packet with the same content again, resulting in a decrease in the overall transmission efficiency of the system.

Contents of the invention

To solve the above problems, the present invention proposes an automatic gain control circuit, a wireless signal receiver including the automatic gain control circuit, and a signal processing method thereof. According to the AGC circuit, receiver and signal processing method of the present invention, a beacon packet sent by the transmitter is used to determine an initial gain value for use by the AGC circuit. This approach helps shorten the time required for the AGC module to find a suitable gain value for subsequent packets sent from the same radio access point. The concept of the present invention can be widely applied to various wireless communication systems that send beacon packets or similar reference signals, not limited to wireless communication systems conforming to the 802.11n communication protocol.

A specific embodiment of the present invention is a wireless signal receiver, which includes a receiving module, an automatic gain control module, a measurement module, a decoding module and a control module. The receiving module is used for receiving a wireless signal. The automatic gain control module is used for adjusting an amplitude of the wireless signal according to a gain value to generate an adjusted signal. The measurement module is used for measuring a signal strength of the adjusted signal. The decoding module is used for decoding the adjusted signal. When the decoding module determines that the adjusted signal corresponds to a beacon packet sent from a transmitter, the control module adjusts the gain value according to the signal strength.

Another specific embodiment according to the present invention is an automatic gain control circuit for dynamically adjusting gain value, which is used for adjusting an amplitude of a wireless signal received by a wireless signal receiver. The automatic gain control circuit includes an automatic gain control module, a measurement module, a decoding module and a control module. The automatic gain control module is used for adjusting an amplitude of the wireless signal according to a gain value to generate an adjusted signal. The measurement module is used for measuring a signal strength of the adjusted signal. The decoding module is used for decoding the adjusted signal. When the decoding module determines that the adjusted signal corresponds to a beacon packet sent from a transmitter, the control module adjusts the gain value according to the signal strength.

Another specific embodiment according to the present invention is a signal processing method applied to a wireless signal receiver. The wireless signal receiver includes an automatic gain control module. The method firstly executes a receiving step: receiving a wireless signal. Then, the method executes an adjustment step: making the automatic gain control module adjust an amplitude of the wireless signal according to a gain value to generate an adjusted signal. Subsequently, the method performs a measuring step of measuring a signal strength of the adjusted signal. Next, the adjusted signal is decoded. When the adjusted signal is determined to correspond to a beacon packet sent from a transmitter, the method performs an adjusting step: adjusting the gain value according to the signal strength.

Description of drawings

In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of a wireless signal receiver according to an embodiment of the invention.

FIG. 2 is a flowchart of a signal processing method according to an embodiment of the invention.

Explanation of component numbers in the figure:

100: wireless signal receiver

11: Receiving module

12: Automatic gain control module

13: Measurement module

14: decoding module

15: Control module

S21～S26: process steps

detailed description

A specific embodiment according to the present invention is a wireless signal receiver, the functional block diagram of which is shown in FIG. 1 . The wireless signal receiver 100 includes a receiving module 11 , an automatic gain control module 12 , a measurement module 13 , a decoding module 14 and a control module 15 . In practical applications, the wireless signal receiver 100 can be integrated into various electronic devices, such as desktop computers, notebook computers, and smart phones, or can exist independently.

According to the 802.11n communication protocol, a wireless access point must periodically broadcast a beacon packet (beacon packet), and carry its service set identifier (SSID), media access Control (media access control, MAC) address, supported transmission rate and other information for the reference of the receiving end that wants to connect to the wireless access point. The wireless signal receiver 100 determines the initial gain value of the automatic gain control module 12 according to the signal strength of the beacon packet. Through the following description, those of ordinary skill in the technical field of the present invention can understand that the concept proposed by the present invention can also be applied to various wireless communication systems that send beacon packets or similar reference signals, and its application scope does not conform to 802.11n The wireless communication system of the communication protocol is limited.

The receiving module 11 is used for receiving a wireless signal and providing the wireless signal to the automatic gain control module 12 . Practically, the receiving module 11 may include but not limited to an antenna. A preset gain value G _default is stored in the wireless signal receiver 100 . The automatic gain control module 12 adjusts the amplitude of the wireless signal with a preset gain value G _default to generate an adjusted signal. The adjusted signal is passed to the measurement module 13 and the decoding module 14 respectively. The measurement module 13 is responsible for measuring the strength of the adjusted signal. The decoding module 14 is used for decoding the adjusted signal. It should be noted that the implementation details of measuring signal strength and decoding are known to those of ordinary skill in the technical field of the present invention, and will not be repeated here.

In one embodiment, the measurement module 13 measures an average strength of the adjusted signal within a preset period of time as the signal strength. For example, the measurement module 13 can calculate the average intensity using the following exponential moving average equation:

E{RSSI[n]}=Coeff_avg*RSSI[n]+(1-Coeff_avg)*E{RSSI[n-1]},

Among them, RSSI[n] represents the latest signal strength sampling value, E{RSSI[n-1]} represents the average strength calculated without the latest signal strength sampling value, and E{RSSI[n]} represents the latest The average strength calculated after sampling the signal strength. Coeff_avg is an average parameter, and its size is not limited to a specific value.

If the decoding module 14 can correctly decode the adjusted signal, and determine that the adjusted signal corresponds to one or more beacon packets sent from a transmitting end, the control module 15 is based on the signal strength E{ RSSI[n]} determines an initial gain value G _initial for use by the automatic gain control module 12 . More specifically, when the AGC module 12 subsequently receives a new wireless signal, it starts from the initial gain value G _initial and dynamically adjusts its gain value according to the amplitude of the input signal. In one embodiment, the control module 15 calculates the initial gain value G _initial according to the following equation:

G _initial [n]=RSSI_to_G _initial (E{RSSI[n]})+offset,

Among them, RSSI_to_G _initial () represents the conversion relationship function between signal strength and gain value, and the parameter offset represents a correction value.

Unless the wireless signal receiver 100 is in a fast-moving state, the signal strength difference of various packets received from the same wireless access device will not be too large. Therefore, resetting the AGC module 12 according to the initial gain value G _initial [n] helps to shorten the time required for the AGC module 12 to find a suitable gain value for subsequent packets sent by the same wireless access point. Thereby, the possibility of the wireless signal receiver 100 missing packets due to the slow operation of the automatic gain control module 12 can be greatly reduced, thereby improving the overall transmission efficiency of the wireless system in which the wireless LAN receiver 100 is located.

In one embodiment, after the automatic gain control module 12 is reset according to the initial gain value G _initial [n], if the decoding module 14 does not decode any packet within a preset reset period, the control module 15 will automatically gain The control module 12 is reset to adopt the preset gain value G _default as the initial gain value, so that the wireless signal receiver 100 restarts to search for a new beacon packet and a corresponding new initial gain value.

In one embodiment, the control module 15 periodically changes the initial gain value adopted by the automatic gain control module 12 according to a latest signal strength. More specifically, the measurement module 13 can be designed to continuously monitor the strength of the beacon packet, and the control module can selectively adjust the initial gain value adopted by the automatic gain control module 12 accordingly, so as to find out the A more appropriate initial gain value.

Another specific embodiment according to the present invention is an automatic gain control circuit for dynamically adjusting gain value, which is used for adjusting an amplitude of a wireless signal received by a wireless signal receiver. The automatic gain control circuit includes an automatic gain control module 12 , a measurement module 13 , a decoding module 14 and a control module 15 shown in FIG. 1 . The automatic gain control circuit can be integrated in various wireless receivers, or can exist independently; its operation mode can be referred to the previous embodiments, and will not be repeated here.

Another specific embodiment according to the present invention is a signal processing method applied to a wireless signal receiver, the flow chart of which is shown in FIG. 2 . The method first executes step S21: receiving a wireless signal. Next, the method executes step S22: making the automatic gain control module adjust an amplitude of the wireless signal according to a gain value to generate an adjusted signal. Subsequently, the method executes step S23: measuring a signal strength of the adjusted signal. The adjusted signal is also decoded in step S24. Step S25 is to determine whether the decoded signal corresponds to one or more beacon packets sent from a transmitter. If the judgment result of step S25 is yes, the method executes step S26: adjusting the gain value according to the signal strength generated in step S23. Relatively, if the determination result of step S25 is no, the process returns to step S21 again.

Practically, steps S21-S26 may be performed periodically and repeatedly. In addition, the various circuit operation changes described above when introducing the wireless signal receiver 100 can also be applied to the signal processing method shown in FIG. 2 , and the details thereof will not be repeated here.

As mentioned above, the present invention provides an automatic gain control circuit, a wireless signal receiver including the automatic gain control circuit, and a signal processing method thereof. According to the automatic gain control circuit, receiver and signal processing method of the present invention, the beacon packet sent by the transmitting end is used to determine an initial gain value for use by the automatic gain control circuit. This approach helps shorten the time required for the AGC module to find a suitable gain value for subsequent packets sent from the same radio access point. The concept of the present invention can be widely applied to various wireless communication systems that send beacon packets or similar reference signals, not limited to wireless communication systems conforming to the 802.11n communication protocol.

With the above detailed description of the preferred embodiments, it is hoped that the features and spirit of the present invention can be described more clearly, and the scope of the present invention is not limited by the preferred embodiments disclosed above. On the contrary, the intention is to cover various modifications and equivalent arrangements within the scope of the appended claims of the present invention.

Claims (15)

1. automatic growth control (AGC) circuit for dynamic adjustment yield value, in order to adjust a wireless signal One amplitude of the wireless signal that receptor receives, comprises:

One automatic growth control module, in order to adjust this amplitude of this wireless signal, to produce according to a yield value Signal after a raw adjustment；

One measurement module, in order to measure a signal intensity of signal after this adjustment；

One decoder module, in order to decode signal after this adjustment；And

One control module, after this decoder module judges this adjustment, signal corresponds to from a transmission end transmission During one beacon package, according to this signal intensity, this control module determines that an initial yield value is for this automatic gain control Molding block uses, and when receiving new wireless signal from this transmission end subsequently, this control module initially increases from this Benefit value starts dynamically to adjust the yield value of this automatic growth control module.

2. automatic gain control circuit as claimed in claim 1, it is characterised in that this measurement module is surveyed Measure a signal mean intensity in a preset period of time after this adjustment, as this signal intensity.

3. automatic gain control circuit as claimed in claim 2, it is characterised in that this measurement module profit This mean intensity is calculated by an index rolling average program.

4. automatic gain control circuit as claimed in claim 1, it is characterised in that this transmission end is week Phase property ground sends this beacon package, and this control module is periodically to adjust this gain according to this signal intensity Value.

5. automatic gain control circuit as claimed in claim 4, it is characterised in that if this decoder module Not solving any package in one presets reset stage, this yield value is reset to one and presets increasing by this control module Benefit value.

6. a wireless signal receiver, comprises:

One receiver module, in order to receive a wireless signal；

One automatic growth control module, in order to adjust an amplitude of this wireless signal, to produce according to a yield value Signal after a raw adjustment；

One measurement module, in order to measure a signal intensity of signal after this adjustment；

One decoder module, in order to decode signal after this adjustment；And

One control module, after this decoder module judges this adjustment, signal corresponds to from a transmission end transmission During one beacon package, according to this signal intensity, this control module determines that an initial yield value is for this automatic gain control Molding block uses, and when receiving new wireless signal from this transmission end subsequently, this control module initially increases from this Benefit value starts dynamically to adjust the yield value of this automatic growth control module.

7. wireless signal receiver as claimed in claim 6, it is characterised in that this measurement module is measured A signal mean intensity in a preset period of time after this adjustment, as this signal intensity.

8. wireless signal receiver as claimed in claim 7, it is characterised in that this measurement module utilizes One index rolling average program calculates this mean intensity.

9. wireless signal receiver as claimed in claim 6, it is characterised in that this transmission end is the cycle Property ground send this beacon package, and this control module is periodically to adjust this yield value according to this signal intensity.

10. wireless signal receiver as claimed in claim 9, it is characterised in that if this decoder module in One preset reset stage in do not solve any package, this yield value is reset to a preset gain by this control module Value.

11. 1 kinds of signal processing methods being applied to a wireless signal receiver, this wireless signal receiver bag Containing an automatic growth control module, this signal processing method comprises:

A () receives a wireless signal；

B () makes this automatic growth control module adjust an amplitude of this wireless signal according to a yield value, to produce Signal after one adjustment；

C () measures a signal intensity of signal after this adjustment；

D () decodes signal after this adjustment, to produce a decoded signal；And

(e) when this decoded signal be judged as corresponding to from one transmission end send a beacon package time, according to This signal intensity adjusts this yield value and determines that an initial yield value is for this automatic growth control module；

And when receiving new wireless signal from this transmission end subsequently, this automatic growth control module is initial from this Yield value starts dynamically to adjust the yield value of this automatic growth control module.

12. signal processing methods as claimed in claim 11, it is characterised in that step (c) comprises measurement should A signal mean intensity in a preset period of time after adjustment, as this signal intensity.

13. signal processing methods as claimed in claim 12, it is characterised in that step (c) comprises and utilizes one Index rolling average program calculates this mean intensity.

14. signal processing methods as claimed in claim 11, comprise further:

Periodically adjust this yield value according to this signal intensity.

15. signal processing methods as claimed in claim 14, comprise further:

If this wireless signal receiver does not solves any package in one presets reset stage, by this yield value weight It is set to a preset gain value.