Wireless communication device and antenna search method thereof

A wireless communication device for linking to an electronic device and including at least one antenna array and a control circuit is provided. The control circuit groups the at least one antenna array to obtain a plurality of test groups. In a scanning operation, the control circuit selects one of the test groups to be a specific test group. In a setting operation, the control circuit groups the specific test group, and re-obtains the plurality of test groups according to the grouped specific test group. The control circuit searches at least one optimal antenna for linking to the electronic device from the at least one antenna array through the scanning operation and the setting operation.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 104102671, filed on Jan. 27, 2015. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to an electronic device and an operation method thereof, and particularly to a wireless communication device and an antenna search method thereof.

Description of Related Art

Smart antenna comprises antenna arrays, and is widely applied in various types of wireless communication systems. For example,FIG. 1is a schematic view illustrating an application of a smart antenna on a wireless local area network (WLAN). As shown inFIG. 1, the smart antenna comprises one antenna array, and the antenna array comprises eight antennas11-18. When an electronic device10enters a reading range of the antenna array, a router120in the wireless local area network establishes a wireless transmission with the electronic device10sequentially through the antennas11-18in the antenna array, and selects one of the antennas11-18to be an optimal antenna for linking to the electronic device10according to signals returned by the electronic device10.

In other words, the router120performs 8 search operations to search the optimal antenna for linking to the electronic device10. Similarly, when the smart antenna includes 4 antenna arrays, and each of antenna arrays includes 8 antennas, the number of times of search operations required for the router120to search the optimal antenna for linking to the electronic device10is 4096 (i.e., 8×8×8×8). Namely, conventional antenna search method leads the router120to consume a lot of time to search optimal antennas for linking to the electronic device10from the antenna arrays, thereby increasing the burden of the router120.

SUMMARY OF THE INVENTION

The invention provides a wireless communication device and an antenna search method thereof to shorten a search time of an antenna through a scanning operation and a setting operation, thereby reducing the burden of the wireless communication device.

A wireless communication device of the invention is suitable for linking to an electronic device and includes at least one antenna array and a control circuit. The control circuit is coupled to the at least one antenna array and groups the at least one antenna array to obtain a plurality of test groups. In addition, in a scanning operation, the control circuit selects one of the plurality of test groups to be a specific test group. In a setting operation, the control circuit groups the specific test group, and re-obtains the plurality of test groups according to the grouped specific test group. Furthermore, the control circuit searches at least one optimal antenna for linking to the electronic device from the at least one antenna array through the scanning operation and the setting operation.

An antenna search method of the invention includes the following steps: grouping at least one antenna array to obtain a plurality of test groups; performing a scanning operation to select one of the plurality of test groups to be a specific test group; performing a setting operation to group the specific test group and re-obtain the plurality of test groups according to the grouped specific test group; and, searching at least one optimal antenna from the at least one antenna array through the scanning operation and the setting operation.

In view of the above, the invention selects a specific test group from a plurality of test groups through a scanning operation, and groups the specific test group through a setting operation to re-obtain the plurality of test groups. Accordingly, at least one optimal antenna for linking to an electronic device is searched from at least one antenna array through a scanning operation and a setting operation, thereby facilitating to shorten a search time of a wireless communication device and further reducing the burden of the wireless communication device.

Several exemplary embodiments accompanied with figures are described in detail below to further describe the invention in details.

DESCRIPTION OF THE EMBODIMENTS

FIG. 2is a schematic view illustrating a wireless communication device according to an embodiment of the invention. As shown inFIG. 2, a wireless communication device200includes a control circuit210and an antenna array220. The control circuit210includes a processor211and a transceiver212, and the antenna array220includes a switch SW2and a plurality of antennas21-2N. In an embodiment, the wireless communication device200may be, for example, a router, and may establish a wireless transmission or a wireless connection with an external electronic device (not shown) through the antenna array220. In addition, during a process of establishing the wireless transmission or the wireless connection, the wireless communication device200searches an optimal antenna for linking or connecting to the electronic device from the antenna array220so as to obtain preferable reception quality and minimize interference between signals.

For example,FIG. 3is a flow chart illustrating an antenna search method according to an embodiment of the invention, and an operation of the wireless communication device200is further described with reference toFIG. 2andFIG. 3. As shown in step S310, the wireless communication device200determines whether an electronic device is detected. For example, when the electronic device enters a reading range of the antenna array220, the wireless communication device200may detect the presence of the electronic device. By contrast, when the electronic device does not enter the reading range of the antenna array220, the wireless communication device200cannot detect the presence of the electronic device.

When the wireless communication device200detects the presence of the electronic device, as shown in step S320, the control circuit210groups at least one antenna array to obtain a plurality of test groups. For example, in an embodiment, the antenna array may, for example, include 8 antennas21-28. In addition, in terms of a detailed step of the step S320, as shown in step S321, the control circuit210divides the antenna array220into two antenna groups, such as an antenna group {21,22,23,24} including the antennas21-24and an antenna group {25,26,27,28} including the antennas25-28. Furthermore, the control circuit210establishes two test groups by using the two antenna groups. Namely, the two antenna groups {21,22,23,24} and {25,26,27,28} are set to be two test groups.

Moreover, as shown in step S330, the control circuit210performs a scanning operation. In addition, in the scanning operation, the control circuit210adopts the plurality of test groups for linking to the electronic device, and selects one of the test groups to be a specific test group. For example, the transceiver212selects the plurality of test groups one by one through at least one switch so as to link to the electronic device through the plurality of test groups one by one. Furthermore, the processor211reads signals from the transceiver212so as to select one of the plurality of test groups to be the specific test group.

As to the detailed steps of the step S330, as shown in step S331, the control circuit210links to the electronic device sequentially through the two test groups {21,22,23,24} and {25,26,27,28}. For example, the transceiver212may, first, be electrically connected to the test group {21,22,23,24} through the switch SW2, and then transmit or receive a radio-frequency (RF) signal though the test group {21,22,23,24}. In addition, the processor211obtains a quality parameter of the test group {21,22,23,24} according to a message or information in the received RF signal. Similarly, the transceiver212may also select the test group {25,26,27,28} through the switch SW2, so that the processor may further obtain a quality parameter of the test group {25,26,27,28}. Namely, in step S331, the control circuit210may link to the electronic device sequentially through the two test groups to obtain two quality parameters in response to each of the two test groups.

It should be noted that the quality parameter of the test group may be, for example, a received signal-strength indicator (RSSI) value or a connection rate. The control circuit210may calculate the connection rate of the test group according to a number of packets which are returned by the electronic device. In addition, as shown in step S332, the control circuit210may select one of the two test groups to be a specific test group according to two quality parameters. For example, the control circuit210may determine a test group which has better reception quality between the two test groups {21,22,23,24} and {25,26,27,28} according to the two quality parameters, and set the test group which has better reception quality to be a specific test group.

Moreover, as shown in step S340, the control circuit210determines whether the specific test group cannot be grouped, namely whether a grouping process for the specific test group is completed. For example, the wireless communication device200may select an antenna from each of the antenna arrays to be an optimal antenna for linking to the electronic device. Namely, when the grouping process for the specific test group is completed, a number of antennas which are adopted for linking to the electronic device is equal to a number of the antenna arrays in the wireless communication device200. Accordingly, the control circuit210may determine whether the number of the antennas in the specific test group is equal to the number of the antenna arrays. In addition, when the number of the antennas in the specific test group is equal to the number of the antenna arrays, the control circuit210determines the grouping process for the specific test group is completed, and then determines the specific test group cannot be grouped. If the number of the antennas in the specific test group is not equal to the number of the antenna arrays, the control circuit210would determine the grouping process for the specific test group is not completed, and then determines the specific test group can be grouped.

For example, if the test group {21,22,23,24} is set to be the specific test group in the step S330, then the control circuit210determines whether the specific test group can be grouped. Furthermore, when the specific test group can be grouped, as shown in step S350, the control circuit210performs a setting operation. Moreover, in the setting operation, the control circuit210groups the specific test group, and re-obtains the plurality of test groups according to the grouped specific test group.

For example, in terms of the detailed steps of the step S350, as shown in step S351, the control circuit210divides the specific test group into two sub-test groups. For example, the control circuit210divides the current specific test group {21,22,23,24} into a sub-test group {21,22} and a sub-test group {23,24}, wherein the sub-test group {21,22} includes antennas21and21, and the sub-test group {23,24} includes antennas23and24. In addition, as shown in step S352, the control circuit210re-establishes the two test groups by using the sub-test group {21,22} and the sub-test group {23,24}. Namely, through the step S350, the two test groups would be re-set to be {21,22} and {23,24}. Moreover, the control circuit210would perform the scanning operation in the step S330one more time to select one of the two current test groups {21,22} and {23,24} to be the specific test group.

If the test group {21,22} is set to be the specific test group in the step S330, the control circuit210would determine that the specific test group {21,22} can be grouped again through the step S340. At this time, the control circuit210would perform the setting operation in the step S350one more time to re-establish the two test groups to be {21} and {22} according to the specific test group {21,22}. In addition, the control circuit210would perform the scanning operation as shown in the step S330one more time to select one of the two current test groups {21} and {22} to be the specific test group. If the test group {21} is set to be the specific test group in the step S330, the control circuit210would determine that the specific test group cannot be grouped again through the step S340. At this time, as shown in step S360, the control circuit210sets the antenna21in the specific test group {21} to be the optimal antenna for linking to an electronic device.

In other words, when the specific test group can be grouped, the control circuit210would perform the setting operation and the scanning operation repeatedly. Namely, the control circuit210would perform the setting operation and the scanning operation repeatedly, until the specific test group can no longer be grouped. Thus, the wireless communication device200may divide the current specific test group one more time into two test groups through the setting operation, and select a test group which has preferable reception quality from these two test groups which are divided again through the scanning operation. In this way, the wireless communication device200may gradually search the optimal antenna for linking to the electronic device from the antenna array220, and further reducing a search time of the wireless communication device200, and further reducing the burden of the wireless communication device200.

For example, in terms of the antenna array220which has 8 antennas21to28, the wireless communication device200would perform the scanning operation three times. In each of the scanning operations, the wireless communication device200uses two test groups to perform the wireless transmission with an electronic device. In other words, the wireless communication device200may perform 6 (i.e., 2+2+2) search operations to search the optimal antenna for linking to the electronic device. However, according to the conventional antenna search method, it would perform 8 search operations to search the optimal antenna for linking to the electronic device. Accordingly, when the number of the antennas in the antenna array220or the number of antenna arrays is increased, the improvement in the search time is increased through the antenna search method as shown inFIG. 3.

It should be noted that the embodiments ofFIG. 2andFIG. 3mainly illustrate the operations of the wireless communication device200with a single antenna array220, but the invention is not limited thereto. For example,FIG. 4is a schematic view illustrating a wireless communication device according to another embodiment of the invention, andFIG. 5is a flow chart illustrating an antenna search method according to another embodiment of the invention. An operation of the wireless communication device which has a plurality of antenna arrays is further described with reference toFIG. 4andFIG. 5.

As shown inFIG. 4, a wireless communication device400includes a control circuit410, an antenna array420, and an antenna array430. In addition, the control circuit410includes a processor411and a transceiver412. The antenna array420includes a switch SW41and a plurality of antennas41-4N, and the antenna array430includes a switch SW42and a plurality of antennas51-5N. The processor411is electrically connected to the transceiver412. Furthermore, the transceiver412may be switched to different antenna of the antenna array420through the switch SW41, and the transceiver412may be switched to different antenna of the antenna array430through the switch SW42. Moreover, in order to facilitate illustration, the following illustration is provided by assuming that the antenna array420and the antenna array430respectively includes four antennas (e.g., the antennas41to44and the antenna51to54), and an operation of the wireless communication device400is illustrated by taking the above assumption as an example.

As shown in step S510, the wireless communication device400determines whether an electronic device (not shown) is detected. When the presence of the electronic device is detected, as shown in step S520, the control circuit410groups at least one antenna array to obtain a plurality of test groups. For example, in terms of the detailed steps of step S520, as shown in step S521, the control circuit410divides each of the antenna arrays into two antenna groups. For example, the antennas41to44of the antenna array420are divided into two antenna groups {41,42} and {43,44}, and the antennas51to54of the antenna array430are divided into two antenna groups {51,52} and {53,54}.

As shown in step S522, the control circuit410combines the divided antenna groups of the antenna arrays into the plurality of test groups, and each of the test groups respectively includes one of the two antenna groups in each of the antenna arrays. For example, the two antenna groups {41,42} and {43,44} of the antenna array420and the two antenna groups {51,52} and {53,54} of the antenna array430may be combined into 22test groups {41,42,51,52}, {41,42,53,54}, {43,44,51,52}, and {43,44,53,54}.

As shown in step S530, the control circuit410performs a scanning operation for linking to the electronic device by adopting the plurality of test groups, and selects one of the test groups to be a specific test group. For example, in terms of the detailed steps of the step S530, as shown in step S531, the control circuit410adopts the test groups {41,42,51,52}, {41,42,53,54}, {43,44,51,52}, and {43,44,53,54} one by one for linking to the electronic device so as to obtain quality parameters of these test groups. In terms of a detailed operation, the transceiver412may be electrically connected to the antennas41and42of the antenna array420through the switch SW41, and be electrically connected to the antennas51and52of the antenna array430through the switch SW42. In this way, the transceiver412is linked to the electronic device through the antennas41,42,51, and52, and further obtaining the quality parameter of the test group {41,42,51,52}. Besides, as shown in step S532, the control circuit410may select one of the test groups to be the specific test group according to the quality parameters.

In addition, as shown in step S540, the control circuit410determines whether the specific test group cannot be grouped. When the specific test group may be grouped, as shown in step S550, the control circuit410performs a setting operation to group the specific test group, and re-obtains the plurality of test groups according to the grouped specific test group. For example, in terms of the detailed steps of step S550, as shown in step S551, the control circuit410selects one of the two antenna groups of each of the antenna arrays to be a specific antenna group according to the test groups. For example, when the test group {41,42,51,52} is selected to be the specific test group, the control circuit410selects the antenna group {41,42} to be the specific antenna group from the two antenna groups {41,42} and {43,44} of the antenna array420and selects the antenna group {51,52} to be the specific antenna group from the two antenna groups {51,52} and {53,54} of the antenna array430.

As shown in step S522, the control circuit410divides the specific antenna group of each of the antenna array into two sub-antenna groups, and re-establishes the two antenna groups of each of the antenna arrays by adopting these two sub-antenna groups of each of the antenna arrays. For example, the control circuit410divides the specific antenna group {41,42} of the antenna array420into two sub-antenna groups {41} and {42}, and re-sets the two antenna groups of the antenna array420as {41} and {42}. Similarly, the specific antenna group {51,52} of the antenna array430is divided into two sub-antenna groups {51} and {52}, such that the two antenna groups of the antenna array430are re-set to be {51} and {52}.

In addition, as shown in step S553, the control circuit410combines the divided sub-antenna groups of the specific antenna groups into a plurality of sub-test groups, and re-establishes the plurality of test groups by adopting the plurality of sub-test groups. For example, the control circuit410may combine the sub-antenna groups {41} and {42} and the sub-antenna groups {51} and {52} into 22test groups {41,51}, {41,52}, {42,51}, and {42,52}. In addition, the control circuit410re-sets the 22test groups by adopting the aforesaid 22test groups. Namely, the 22test groups would be re-set to be {41,51}, {41,52}, {42,51} and {42,52}.

Then, the control circuit410performs the scanning operation as shown in the step S530again. In addition, in the scanning operation, the control circuit410adopts the test groups {41,51}, {41,52}, {42,51} and {42,52} for linking to the electronic device, and selects one of the plurality of test groups {41,51}, {41,52}, {42,51} and {42,52} to be the specific test group. Furthermore, if the test group {41,51} is set to be the specific test group in the step S530, then the control circuit410would determine that the specific test group cannot be grouped through the step S540. At this time, as shown in step S560, the control circuit410sets up the antenna41and the antenna51of the specific test group {41,51} to be optimal antennas for linking to the electronic device. Namely, the antenna41of the antenna array420and the antenna51of the antenna array430may be set to be the optimal antennas for linking to the electronic device. It is noted that the number of selected antenna is equal to the number of antenna array. In this embodiment, the number of the selected antenna is 2 and the number of antenna array is 2.

In other words, the control circuit410may perform the scanning operation and the setting operation repeatedly, until the specific test group can no longer be grouped. In addition, in terms of the antenna arrays420and430which respectively have four antennas, the wireless communication device400performs the scanning operation two times. And, in each of the scanning operations, the wireless communication device400adopts four test groups to perform the wireless transmission with the electronic device. In other words, the wireless communication device400may perform 8 (i.e., 4+4) search operations to search the optimal antennas for linking to the electronic device. Accordingly, when the wireless communication device400includes R antenna arrays and each of the antenna arrays includes N antennas, the wireless communication device400may search optimal antennas for linking to an electronic device through, approximately, 2R×log2N search operations, wherein R is a positive integer, and N is an integer greater than 1. For example, when R=4 and N=8, the wireless communication device400may perform 48 search operations to search the optimal antennas for linking to the electronic device. However, according to the conventional antenna search method, it would perform 4096 search operations before the optimal antennas for linking to the electronic device are found. In other words, the antenna search method as described in the present embodiment may effectively reduce time for searching the optimal antennas for linking to the electronic device through the antenna arrays.

In addition, the number R of the antenna arrays and the number N of the antenna provided in each of the antenna arrays may also be in odd numbers. For example, the antenna array220in the wireless communication device200depicted inFIG. 2may also include, for example, five antennas21-25. In terms of operations, the antennas21to25may, first, be divided into two antenna groups {21,22,23} and {24,25} in the step S320, such that the wireless communication device200adopts two test groups {21,22,23} and {24,25} for linking to the electronic device in the step S330. Furthermore, when the test group {24,25} is selected to be a specific test group in the step S330, the specific test group {24,25} may be divided into two test groups {24} and {25} through the step S350, and the wireless communication device200may perform the step S330again to select one of the two test groups {24} and {25} to be the specific test group. In other words, when R=1 and N=5, a mathematic equation 21×log25=2×2.322. At this time, the minimum number of times for search operations of the wireless communication device200is four (i.e., 21×2), and the maximum number of times thereof may be six (i.e., 21×3). Accordingly, when R=3 and N=5, a mathematic equation 23×log25=8×2.322. At this time, the minimum number of times for search operations of the wireless communication device200is 16 (i.e., 23×2), and the maximum number of times thereof may be 24 (i.e., 23×3).

In summary, the invention selects a specific test group from a plurality of test groups by adopting a scanning operation, and groups the specific test group through a setting operation to re-obtain the plurality of test groups. Accordingly, at least one optimal antenna for linking to an electronic device is searched from at least one antenna array through a scanning operation and a setting operation, thereby facilitating to shorten a search time of a wireless communication device and further reducing the burden of the wireless communication device.

Although the invention has been disclosed with reference to the aforesaid embodiments, they are not intended to limit the invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the disclosure cover modifications and variations of the specification provided they fall within the scope of the following claims and their equivalents.