KR100600707B1 - Method for receiving wireless signal - Google Patents

Abstract

Disclosed is a wireless signal receiving method considering multipath. The wireless signal receiving method according to the present invention comprises the steps of: transmitting a test signal in a wireless transceiver having a plurality of receiving antennas having different directivity and transmitting antenna, receiving a test signal at the plurality of receiving antennas, a plurality of Determining the uniformity of power of the test signal received by the reception antenna of the receiver to determine whether there is a multipath to the periphery of the wireless transceiver, and when the multipath exists, which of the plurality of reception antennas Setting one to a fixed antenna. According to the radio signal reception method, the radio signal transmitting side or the radio signal receiving side itself determines whether a multipath exists in the surrounding environment and determines a path that satisfies an optimal reception sensitivity in a wireless network environment. Transients generated during signal reception can be minimized and the electric field strength of the received radio signal can be kept constant.

Wireless network, receive antenna, field strength, main pass, multipath

Description

Method for receiving wireless signal considering multipath {Method for receiving wireless signal}

1 is a diagram illustrating an example in which a general wireless network environment is applied to real life;

2 is a diagram illustrating an example of a reception antenna provided in a network interface card;

3A and 3B are diagrams showing electric field strength for the reception antenna shown in FIG. 2; and

4 is a flowchart illustrating an embodiment of a method for receiving radio signals in consideration of multipath according to the present invention.

The present invention relates to a radio signal reception method, and more particularly to a radio signal reception method for maintaining a consistent reception sensitivity while minimizing the transient occurring at the reception side by a multipath formed between the transmission side and the reception side of the radio signal. It is about.

Wireless networks that transmit and receive data in wireless network environments are increasingly replacing wired networks. The wireless network is configured to transmit and receive wireless data to and from information processing devices (eg, notebooks, PDAs, personal computers) and AV (Audio and Video) devices located within a signal transmission distance around an access point (AP). The access point is connected to the wired Internet network. Access points are located at appropriate distances in offices, homes, and public places to form a network, thereby eliminating the problem of data transmission in the existing wired network environment, that is, the information processing device or AV device must always be wired for data transmission. I'm solving it.

1 illustrates an example in which a general wireless network environment is applied to real life.

The illustrated example illustrates a concept of wirelessly transmitting a video signal received from a set-top box (STB) 2 to an image display device 5 such as a television and an LCD using an access point (AP) 1. Indicates. In the figure, an access point (AP) 1 can be connected to a personal computer (PC) 3 and an AV device (AV) 4 in addition to the set-top box (STB) 2, and the AV from these devices. The signals may be relayed to each other or transmitted to the image display device (Display) 5. Here, in order to establish a wireless network environment, a personal computer (PC) 3, an AV device (AV) 4, a set-top box (STB) 2, and an image playback device (Display) 5 are all wireless networks. A network interface card (eg 2a) must be provided for the connection. Although not shown in the drawing, network interface cards (e.g., 2a, 5a) are not only set-top boxes (STBs) 2, video playback devices (Display) 5, but also personal computers (PC) 3, and AV devices (AV). It should also be provided in (4). On the other hand, the devices that are wirelessly connected to the access point (AP) (1) may be located in a location that is not adjacent to each other in the home or office, and forms a multipath according to the location and the surrounding medium. If there is a reflective material (e.g. metal, glass, etc.) between the access point (AP) 1 and the devices that are wirelessly connected, the access point (AP) 1 and these wirelessly connected devices may be multi-pass. ) Can be formed. In general, multipath interferes with a channel having a different frequency in the surroundings, and when a channel interfered signal is received at a receiver, reception sensitivity is reduced. In order to solve such a problem, conventionally, as shown in FIG. 2, a wireless device connected to an access point (AP) 1, for example, a personal computer (PC) 3, an AV device (AV) 4, Arrangement of a plurality of antennas ①, ②, ③ having different directivities on a network interface card (for example, 2a, 5a) mounted on the set top box (STB) 2 and the image reproduction apparatuses (5). Through these antennas, radio signals of a path having the best reception sensitivity are received. Typically, such receiving antennas ①, ②, ③ are formed in a thin film form on a printed circuit board (PCB), the antenna is formed in different directions as shown in FIG. However, in receiving radio signals through the plurality of receiving antennas (1, 2, 3) in this way, when the multipath changes frequently, the network interface cards (for example, 2a, 5a) correspond to the paths with the best reception sensitivity. The receiving antennas (one of ①, ②, ③) should be switched and selected, and transients will occur when switching. Transients reduce the stability of network interface cards (e.g. 2a, 5a) including antennas (1), (2) and (3), or information processing devices and AV devices (AV) 4 having the same. In addition, when a large number of glass or metallic materials having high reflectance for the wireless signal are disposed in a home or office, the multipath is continuously changed when the reflective medium moves around the wireless devices, thereby receiving antennas (1, 1, 2). ②, ③) when switching, the reception sensitivity of the plurality of antennas (①, ②, ③) provided in each of the network interface cards (for example, 2a, 5a) is changed. According to the switching of the receiving antennas ①, ②, ③, the network interface cards (for example, 2a, 5a) are difficult to keep the electric field strength of the received radio signal constant.

Accordingly, an object of the present invention is to determine whether a multipath exists for the surrounding environment at the transmitting side of the wireless signal or the receiving side of the wireless signal itself, and to determine a path that satisfies the optimal reception sensitivity. It is to provide a wireless signal receiving method that can minimize the transient phenomenon and keep the electric field strength of the received wireless signal constant.

The above object is to emit a test signal in a wireless transceiver having a plurality of receiving antennas having a different directivity, and a transmitting antenna, according to the present invention, receiving the test signal at the plurality of receiving antennas, Determining the presence or absence of a multipath to the periphery of the wireless transceiver by determining the uniformity of power of the test signal received by the plurality of receiving antennas, and if the multipath exists, the plurality of Is achieved by setting any one of the receive antennas of to a fixed antenna.

The setting of the fixed antenna may be performed when a deviation between power values for the test signals received by the plurality of receiving antennas is greater than a predetermined deviation.

In the setting of the fixed antenna, the receiving antenna having the largest power value among the power values may be set as the fixed antenna.

Preferably, when the difference between the power values is less than a predetermined difference value, the fixed antenna is a receiving antenna receiving a test signal having the least channel interference by other frequencies among the test signals received by the plurality of receiving antennas Set to.

The determining of the presence or absence of the multipath may be determined based on whether other channels interfere with the test signals received by the plurality of receiving antennas.

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 and 2.

3A and 3B are diagrams showing electric field strengths of the receiving antennas ①, ②, and ③ shown in FIG. 2, and the process of selecting a receiving antenna according to the electric field strength will be conceptually described in the present invention. .

First, FIG. 3A illustrates an example of electric field strength received from the reception antennas ①, ②, and ③ illustrated in FIG. 2. In the figure, the strength of the electric field strength is the largest of the receiving antenna ① and the smallest of the receiving antenna ② and the receiving antenna ③. The deviation between the electric field strength of the receiving antenna ① and the receiving antenna ② is about 40 dB, and it can be seen that the receiving antenna ① receives a radio signal according to a main pass. In the drawing, reference numeral “p _th ” denotes a deviation between the maximum power value and the minimum power value of each receiving antenna ①, ②, ③. The deviation value may be used as a reference value for distinguishing the main path and the multipath. As shown in FIG. 3B, when the deviation value is set to 20 μs, when the difference in electric field strength between the receiving antenna ① and the receiving antenna ② does not exceed 20 μs, the receiving antenna ① according to the main path is used. It may be used as a criterion for determining that the radio signal is not received. That is, the field strength difference between a receiving antenna (eg ①) that receives a radio signal of the largest field strength and a receiving antenna (eg ②, ③) that receives a radio signal of the next or smallest field strength does not exceed the deviation value. In this case, the receiving antenna with the largest field strength is not selected as the fixed antenna. In this case, among the test signals received by the receiving antennas (①, ②, ③) as the criteria for distinguishing the main path and the multipath, the test signal having the least channel interference by other frequencies is regarded as the signal by the main path. This compares the signal transmitted by the network interface card (for example, 2a) provided in the set-top box (STB) 2 or the set-top box (STB) 2 with the signals received by the receiving antennas (1, 2, 3). The frequency of the transmitted test signal may be compared with the frequency of the received test signal.

4 is a flowchart illustrating an embodiment of a method for receiving radio signals in consideration of multipath according to the present invention.

First, the set-top box (STB) 2 wirelessly connected to the access point (AP) 1 transmits a test signal to the surroundings through the network interface card 2a (S100). The test signal may transmit a broadcast signal received from the set-top box (STB) 2 and does not require a special pattern. Next, the test signal transmitted from the set top box (STB) (2) is reflected or refracted according to the surrounding environment is returned to the network interface card (for example, 2a) provided in the set top box (STB) (2). The network interface card (for example, 2a) may be provided with receiving antennas ①, ②, ③ of the type shown in FIG. 2, and these receiving antennas ①, ②, ③ receive the returned radio signals ( S110), by analyzing the electric field strength of the received wireless signal, it is determined whether or not a multipath is formed in the periphery (S120). For example, when the electric field strengths received by the receiving antennas ①, ②, and ③ have almost the same value, it may be determined that there is no multipath, and in the opposite case, it may be determined that the multipath exists.

When the field strengths of the test signals received by the receiving antennas ①, ②, and ③ are almost the same, the field strengths of the test signals transmitted from the set-top box STB 2 are almost the same. Since it returns, it indicates that there is no section in which a multipath is formed in a specific direction among test directions. On the contrary, when the field strengths of the test signals received from each of the receiving antennas ①, ②, and ③ differ greatly, the paths transmitted and returned according to the direction of the test signal transmitted from the STB 2 are returned. Is changed, or reflected, refracted, or absorbed, so the receiving antennas (①, ②, ③) receiving the largest field strength among the test signals received by the receiving antennas (①, ②, ③) are set as fixed antennas. do. Thereafter, the network interface card (for example, 2a) of the set-top box (STB) 2 receives the radio signal only through the reception antenna set as the fixed antenna, and does not change the fixed antenna according to the surrounding environment. On the other hand, even if the electric field strength received from each of the receiving antenna (①, ②, ③) is somewhat different, it is possible to re-interpret the presence of multipath according to the preset deviation value as described above with reference to FIG. 3B. At this time, the criterion of the main path is to select the test signal having the least channel interference by the other frequency among the test signals received by the receiving antennas (①, ②, ③) as the signal by the main path, and the test selected as the main path. The receiving antenna receiving the signal is set as a fixed antenna. Accordingly, since the reception antennas (①, ②, ③) are not switched by selection according to the change of the surrounding environment, the wireless signal reception method according to the present invention generates a transient phenomenon when switching the reception antennas (①, ②, ③). Since the radio signal is received using only the fixed antenna, the electric field strength of the received radio signal can be kept constant.

As described above, the present invention determines whether there is a multipath for the surrounding environment at the transmitting side of the wireless signal or the receiving side of the wireless signal in a wireless network environment, and determines a path that satisfies an optimal reception sensitivity. Transients generated during signal reception can be minimized and the electric field strength of the received radio signal can be kept constant.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-described specific embodiments, and the present invention is not usually limited to the scope of the present invention as claimed in the claims. Anyone of ordinary skill in the art can make various modifications, as well as such changes are within the scope of the claims.

Claims (5)

Emitting a test signal in a wireless transceiver having a plurality of receiving antennas having different directivity and transmitting antennas; Receiving the test signal at the plurality of receive antennas; Analyzing the uniformity of power of the test signals received by the plurality of receiving antennas to determine whether a multipath exists in the vicinity of the wireless transceiver; And And setting one of the plurality of receiving antennas as a fixed antenna when the multipath exists as a result of the determination. The method of claim 1, Setting to the fixed antenna, And a deviation between power values for the test signals received by the plurality of receiving antennas is greater than a predetermined deviation. The method of claim 2, Setting to the fixed antenna, And receiving antenna having the largest power value among the power values as the fixed antenna. The method of claim 3, When the difference between the power values does not reach a preset difference value, the receiving antenna receiving the test signal having the least channel interference by another frequency among the test signals received by the plurality of receiving antennas is set as a fixed antenna. Wireless signal reception method considering the multipath characterized in that. The method of claim 1, The determining of the presence of the multipath, The radio signal reception method according to the multipath, characterized in that it is determined according to the interference of other channels to the test signal received by the plurality of receiving antennas.

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