Abstract:
A wireless transmission system is provided for receiving a wireless signal in a wireless electronic device. The wireless transmission system includes a first antenna for vertical polarization, a second antenna for horizontal polarization, a sensor module for sensing pose status of the wireless electronic device and generating a control signal, and a controllable switch coupled to the first antenna and the second antenna for selecting one of the first antenna and the second antenna as an active antenna for receiving the wireless signal according to the control signal. With the aid of the two antennas, signal that comes from any direction can be received efficiently. Furthermore, one omni-directional antenna is used for transmitting signal. All the antennas are internal, and have better throughput performance than external antennas.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates in general to a wireless transmission system and, more particularly, to a wireless transmission system having architecture based on three internal antennas that can have better communication range than external antenna. 
         [0003]    2. Description of the Prior Art 
         [0004]    Please refer to  FIG. 1 .  FIG. 1  shows a schematic functional block diagram illustrating a wireless transmission system  110  installed in a wireless electronic device  100  according to a prior art. The wireless electronic device  100  comprises an antenna  101 , a wireless transmission system  110 , and a functional circuit  150 . 
         [0005]    The functional circuit  150  is utilized to process functional operations, such as broadband signal processing, printing, routing, print serving, etc., of the wireless electronic device  100 . The prior-art antenna  101  is usually an external antenna such as an antenna dipole with stretchable design and being capable of rotating for pointing toward a certain direction. The wireless transmission system  110  comprises a receiving front end  115 , a transmitting front end  120 , an analog-to-digital converter  125 , a digital-to-analog converter  130 , and a digital signal processor  135 . 
         [0006]    The receiving front end  115  functions to amplify and demodulate a wireless signal received from the antenna  101  for generating an internal received signal. The analog-to-digital converter  125  functions to convert the internal received signal in analog form generated by the receiving front end  115  into an internal received signal in digital form. The digital signal processor  135  processes the internal received signal in digital form for providing a received functional signal to the functional circuit  150 . 
         [0007]    Furthermore, the digital signal processor  135  processes a transmitting functional signal provided by the functional circuit  150  for generating a transmitting signal in digital form. The digital-to-analog converter  130  converts the transmitting signal in digital form into a transmitting signal in analog form. The transmitting front end  120  functions to modulate and amplify the transmitting signal in analog form for generating a wireless transmitting signal to be transmitted by the antenna  101 . 
         [0008]    It is well known that the wireless transmission signal is carried in an electromagnetic wave, and the electromagnetic wave is actually polarized. Accordingly, a wide-used antenna dipole is able to receive a polarized wireless signal efficiently only when the polarization is the same as the transmitting antenna. However, rotating of the antenna dipole for pointing toward a best direction for wireless signal receiving is usually performed manually, which is inconvenient to end users. The situation is even worse when the wireless electronic device is moveable and can be placed in different pose status, which means that orientation of the antenna dipole of the wireless electronic device is adjusted manually each time when the wireless electronic device is moved or changes pose status. 
         [0009]    For that reason, there is a big need for providing a low-power wireless transmission system having high performance of wireless signal receiving to solve the aforementioned problems. 
       SUMMARY OF THE INVENTION 
       [0010]    It is therefore a primary objective of the present invention to provide a low-power wireless transmission system having high performance of wireless signal receiving to solve the prior art problems. 
         [0011]    In accordance with an objective of the present invention, a wireless transmission system for used in a wireless electronic device is provided for achieving high performance of wireless signal receiving. The wireless transmission system comprises: a first antenna for receiving a first wireless receiving signal in a first polarized direction (vertical); a second antenna for receiving a second wireless receiving signal in a second polarized direction (horizontal); a sensor module for sensing pose status of the wireless electronic device and generating a control signal; and a controllable switch, coupled to the first antenna and the second antenna, for selecting a best wireless receiving signal out of the first wireless receiving signal and the second wireless receiving signal as an active signal to be processed by the wireless electronic device. 
         [0012]    The present invention further provides a wireless transmission method for receiving a wireless signal in a wireless electronic device. The wireless transmission method comprises: installing a first antenna and a second antenna in the wireless electronic device; receiving a first wireless signal from the first antenna and a second wireless signal from the second antenna; amplifying and demodulating the first wireless signal by a first receiving front end and the second wireless signal by a second receiving front end for generating a first internal signal and a second internal signal respectively; sensing pose status of the wireless electronic device by a pose sensor for generating a control signal; and selecting one of the first internal signal and the second internal signal as an active internal signal to be processed by the wireless electronic device according to the control signal. 
         [0013]    Moreover, the present invention provides a wireless transmission method for receiving a wireless signal in a wireless electronic device. The wireless transmission method comprises: installing a plurality of antennas in a wireless electronic device; receiving a plurality of wireless signals from the plurality of antennas; amplifying and demodulating the plurality of wireless signals by a plurality of receiving front ends for generating a plurality of internal signals respectively; sensing pose status of the wireless electronic device by a pose sensor for generating a control signal; and selecting one of the plurality of internal signals as an active internal signal to be processed by the wireless electronic device according to the control signal. 
         [0014]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The above and other objects and features of the present invention will become apparent from the subsequent description of preferred embodiments given in conjunction with the following accompanying drawings. 
           [0016]      FIG. 1  shows a schematic functional block diagram illustrating a wireless transmission system installed in a wireless electronic device according to a prior art. 
           [0017]      FIG. 2  sets forth a schematic functional block diagram illustrating a wireless transmission system installed in a wireless electronic device according to the present invention. 
           [0018]      FIG. 3  presents a schematic functional block diagram illustrating a wireless transmission system installed in a wireless electronic device in accordance with a first preferred embodiment of the present invention. 
           [0019]      FIG. 4  presents a schematic functional block diagram illustrating a wireless transmission system installed in a wireless electronic device in accordance with a second preferred embodiment of the present invention. 
           [0020]      FIG. 5  shows a flowchart depicting a wireless transmission method according to the present invention. 
           [0021]      FIG. 6  shows a flowchart depicting another wireless transmission method according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Here, it is to be noted that the present invention is not limited thereto. 
         [0023]    Please refer to  FIG. 2 .  FIG. 2  sets forth a schematic functional block diagram illustrating a wireless transmission system  210  installed in a wireless electronic device  200  according to the present invention. The wireless electronic device  200  can be a personal computer, a digital camera, a gateway, a router, a gateway router, a print server, etc. The wireless electronic device  200  comprises a wireless transmission system  210  and a functional circuit  250 . 
         [0024]    The functional circuit  250  is utilized to process functional operations, such as image processing, printing, routing, etc., of the wireless electronic device  200 . 
         [0025]    The wireless transmission system  210  comprises a first antenna  201 , a second antenna  202 , a third antenna  203 , a first receiving front end  215 , a second receiving front end  216 , a transmitting front end  220 , a controllable switch  231 , a sensor module  233 , and a signal processor  235 . The first antenna  201  and the second antenna  202  are arranged to efficiently receive wireless signals in different polarized directions. Furthermore, the first antenna  201  and the second antenna  202  are both internal antennas such as internal printed or flat antennas oriented in different directions. The polarized direction of the second antenna can be perpendicular to the polarized direction of the first antenna. The third antenna  203  is utilized to transmit wireless signals and is also an internal antenna. Therefore, there is no external antenna stretching outside the wireless electronic device  200 , which results in a generic pleasant structure of the wireless electronic device  200 . 
         [0026]    The first receiving front end  215  is coupled to the first antenna  201  and functions to amplify and demodulate a first received signal received from the first antenna  201  so as to generate a first internal received signal. The second receiving front end  216  is coupled to the second antenna  202  and functions to amplify and demodulate a second received signal received from the second antenna  202  so as to generate a second internal received signal. 
         [0027]    The sensor module  203  functions to sense the pose status of the wireless electronic device  250  and generates a control signal according to the sensed pose status. The controllable switch  231  is utilized to select one of the first internal received signal and the second internal received signal so as to transfer the selected internal received signal to the signal processor  235  according to the control signal from the sensor module  233 . The controllable switch  231  can be a multiplexer, an electronic relay, or a mechanical relay. The control signal is generated for selecting an optimal internal received signal from the most efficient antenna on the pose status. 
         [0028]    For instance, the controllable switch  231  may transfer the first internal received signal to the signal processor  235  when the wireless electronic device  200  is placed in a horizontal pose status, and the controllable switch  231  may transfer the second internal received signal to the signal processor  235  when the wireless electronic device  200  is placed in a vertical pose status. 
         [0029]    The signal processor  235  processes the selected internal received signal for providing a received functional signal to the functional circuit  250 . Furthermore, the signal processor  235  processes a transmitting functional signal provided by the functional circuit  250  for generating an internal transmitting signal. The transmitting front end  220  functions to modulate and amplify the internal transmitting signal so as to generate a transmitting signal to be transmitted by the third antenna  203 . 
         [0030]    Based on the above description, the wireless transmission system  210  is able to automatically select one of the first antenna and the second antenna as an active antenna for high-efficient wireless signal receiving. As a result, the wireless electronic device  200  is able to perform a high-efficiency wireless signal receiving operation regardless of the pose status of the wireless electronic device  200 . Please note that the aforementioned wireless transmission system is able to modify effortlessly for more than two receiving antennas having different polarized directions, which is still within the scope of the present invention. 
         [0031]    Please refer to  FIG. 3 .  FIG. 3  presents a schematic functional block diagram illustrating a wireless transmission system  310  installed in a wireless electronic device  300  in accordance with a first preferred embodiment of the present invention. The wireless electronic device  300  comprises a wireless transmission system  310  and a functional circuit  350 . 
         [0032]    The functional circuit  350  is utilized to process functional operations, such as image processing, printing, routing, etc., of the wireless electronic device  300 . 
         [0033]    The wireless transmission system  310  comprises a horizontal polarized antenna  301 , a vertical polarized antenna  302 , a Planar Inverted F antenna (PIFA)  203 , a first receiving front end  315 , a second receiving front end  316 , a transmitting front end  320 , a multiplexer  331 , a pose sensor  332 , a signal processing circuit  333 , an analog-to-digital converter  325 , a digital-to-analog converter  330 , and a digital signal processor  335 . 
         [0034]    The horizontal polarized antenna  301  is arranged to efficiently receive wireless signals in horizontal polarized direction. The vertical polarized antenna  302  is arranged to efficiently receive wireless signals in vertical polarized direction. The horizontal polarized antenna  301  and the vertical polarized antenna  302  are both internal antennas such as internal printed or flat antennas oriented in horizontal and vertical directions respectively. 
         [0035]    The PIFA antenna  303  is utilized to transmit wireless signals and is also an internal antenna. Therefore, there is still no external antenna stretching outside the wireless electronic device  300 , which results in a generic pleasant structure of the wireless electronic device  300 . 
         [0036]    The first receiving front end  315  is coupled to the horizontal polarized antenna  301  and functions to amplify and demodulate a first received signal received from the horizontal polarized antenna  301  so as to generate a first internal received signal. The second receiving front end  316  is coupled to the vertical polarized antenna  302  and functions to amplify and demodulate a second received signal received from the vertical polarized antenna  202  so as to generate a second internal received signal. 
         [0037]    The pose sensor  332  functions to sense the pose status of the wireless electronic device  350  and generates a sensing signal. The pose sensor  332  can be a signal processing unit that performs the calculation for generating the sensing signal. The signal processing circuit  333  processes the sensing signal for generating a control signal. The multiplexer  331  is utilized to select one of the first internal received signal and the second internal received signal as an active internal received signal according to the control signal. The control signal is generated for selecting an optimal internal received signal from the most efficient antenna on the pose status. 
         [0038]    For instance, the multiplexer  331  may transfer the first internal received signal to the digital signal processor  335  when the wireless electronic device  300  is placed in a horizontal pose status, and the multiplexer  331  may transfer the second internal received signal to the digital signal processor  335  when the wireless electronic device  300  is placed in a vertical pose status. 
         [0039]    The active internal received signal is converted into a digital received signal by the analog-to-digital converter  325 . The digital signal processor  335  processes the digital received signal for providing a digital received functional signal to the functional circuit  350 . Furthermore, the digital signal processor  335  processes a digital transmitting functional signal provided by the functional circuit  350  for generating a digital internal transmitting signal. The digital-to-analog converter  330  converts the digital internal transmitting signal into an analog internal transmitting signal. The transmitting front end  320  functions to modulate and amplify the analog internal transmitting signal so as to generate a transmitting signal to be transmitted by the PIFA antenna  303 . 
         [0040]    Based on the above description, the wireless transmission system  310  is able to automatically select one of the horizontal polarized antenna and the vertical polarized antenna as an active antenna for high-efficient wireless signal receiving. As a result, the wireless electronic device  300  is able to perform a high-efficiency wireless signal receiving operation regardless of the pose status of the wireless electronic device  300 . 
         [0041]    Please refer to  FIG. 4 .  FIG. 4  presents a schematic functional block diagram illustrating a wireless transmission system  410  installed in a wireless electronic device  400  in accordance with a second preferred embodiment of the present invention. The wireless electronic device  400  comprises a wireless transmission system  410  and a functional circuit  450 . 
         [0042]    The functional circuit  450  is utilized to process functional operations, such as image processing, printing, routing, etc., of the wireless electronic device  400 . 
         [0043]    The wireless transmission system  410  comprises a horizontal polarized antenna  401 , a vertical polarized antenna  402 , a Planar Inverted F antenna (PIFA)  403 , a first low-noise amplifier  411 , a first filter  413 , a first demodulator  415 , a second low-noise amplifier  412 , a second filter  414 , a second demodulator  416 , a transmitting power amplifier  420 , a modulator  421 , an electronic relay  431 , a pose sensor  432 , a signal processing circuit  433 , and an analog signal processor  435 . 
         [0044]    The horizontal polarized antenna  401  is arranged to efficiently receive wireless signals in horizontal polarized direction. The vertical polarized antenna  402  is arranged to efficiently receive wireless signals in vertical polarized direction. The horizontal polarized antenna  401  and the vertical polarized antenna  402  are both internal antennas such as internal printed or flat antennas oriented in horizontal and vertical directions respectively. 
         [0045]    The PIFA antenna  403  is utilized to transmit wireless signals and is also an internal antenna. Therefore, there is still no external antenna stretching outside the wireless electronic device  400 , which results in a generic pleasant structure of the wireless electronic device  400 . 
         [0046]    The first low-noise amplifier  411  is coupled to the horizontal polarized antenna  401  and functions to amplify a first received signal received from the horizontal polarized antenna  401  so as to generate a first amplified signal. The first filter  413  performs filtering process on the first amplified signal for extracting desired band signal to generate a first filtered signal. The first demodulator  415  performs demodulating process on the first filtered signal to generate a first internal received signal. 
         [0047]    The second low-noise amplifier  412  is coupled to the vertical polarized antenna  402  and functions to amplify a second received signal received from the vertical polarized antenna  402  so as to generate a second amplified signal. The second filter  414  performs filtering process on the second amplified signal for extracting desired band signal to generate a second filtered signal. The second demodulator  416  performs demodulating process on the second filtered signal to generate a second internal received signal. 
         [0048]    The pose sensor  432  functions to sense the pose status of the wireless electronic device  450  and generates a sensing signal. The signal processing circuit  433  processes the sensing signal for generating a control signal. The electronic relay  431  is utilized to select one of the first internal received signal and the second internal received signal as an active internal received signal according to the control signal. The control signal is generated for selecting an optimal internal received signal from the most efficient antenna on the pose status. 
         [0049]    For instance, the electronic relay  431  may transfer the first internal received signal to the analog signal processor  435  when the wireless electronic device  400  is placed in a horizontal pose status, and the electronic relay  431  may transfer the second internal received signal to the analog signal processor  435  when the wireless electronic device  400  is placed in a vertical pose status. 
         [0050]    The analog signal processor  435  processes the active internal received signal for providing a received functional signal to the functional circuit  450 . Furthermore, the analog signal processor  435  processes a transmitting functional signal provided by the functional circuit  450  for generating an internal transmitting signal. The modulator  421  performs modulating process on the internal transmitting signal to generate a modulated transmitting signal. The transmitting power amplifier  420  functions to amplify the modulated transmitting signal so as to generate a transmitting signal to be transmitted by the PIFA antenna  403 . 
         [0051]    Based on the above description, the wireless transmission system  410  is able to automatically select one of the horizontal polarized antenna and the vertical polarized antenna as an active antenna for high-efficient wireless signal receiving. As a result, the wireless electronic device  400  is able to perform a high-efficiency wireless signal receiving operation regardless of the pose status of the wireless electronic device  400 . 
         [0052]    Please refer to  FIG. 5 .  FIG. 5  shows a flowchart depicting a wireless transmission method according to the present invention. The transmission method in  FIG. 5  comprises the following steps:
   Step S 51 : installing two antennas for receiving and one antenna for transmitting in a wireless electronic device;   Step S 52 : receiving a first wireless signal from the first vertical-polarized antenna and a second wireless signal from the second horizontal-polarized antenna;   Step S 53 : amplifying and demodulating the first wireless signal by a first receiving front end and the second wireless signal by a second receiving front end for generating a first internal signal and a second internal signal respectively;   Step S 54 : sensing pose status of the wireless electronic device by a pose sensor for generating a control signal;   Step S 55 : choosing one of the two antennas to receive signal for next period of time based on the control signal;   Step S 56 : processing the best-received signal from the chosen antenna for providing a functional signal to a functional circuit of the wireless electronic device;   Step S 57 : transmitting a signal from the functional circuit of the wireless electronic device via an omni-directional antenna;   Step S 58 : Detecting whether or not pose status of the wireless electronic device changes, if pose status of the wireless electronic device changes, then go to step S 52 , otherwise go to step S 59 ; and   Step S 59 : amplifying and demodulating a best-received signal from the chosen antenna, go to step S 56 .   
 
         [0062]    Please refer to  FIG. 6 .  FIG. 6  shows a flowchart depicting another wireless transmission method according to the present invention. The transmission method in  FIG. 6  comprises the following steps:
   Step S 61 : installing a plurality of antennas in a wireless electronic device;   Step S 62 : receiving a plurality of wireless signals from the plurality of antenna (including vertical-polarized antenna and horizontal-polarized antenna);   Step S 63 : amplifying and demodulating the plurality of wireless signals by a plurality of receiving front ends for generating a plurality of internal signals respectively;   Step S 64 : sensing pose status of the wireless electronic device by a pose sensor for generating a control signal;   Step S 65 : choosing one of the plurality of antennas to receive signal for next period of time based on the control signal;   Step S 66 : processing the best-received signal from the chosen antenna for providing a functional signal to a functional circuit of the wireless electronic device;   Step S 67 : transmitting a signal from the functional circuit of the wireless electronic device via an omni-directional antenna;   Step S 68 : Detecting whether or not pose status of the wireless electronic device changes, if pose status of the wireless electronic device changes, then go to step S 62 , otherwise go to step S 69 ; and   Step S 69 : amplifying and demodulating a best-received signal from the chosen antenna, go to step S 66 .   
 
         [0072]    While the invention has been shown and described with respect to the preferred embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.