Abstract:
A system for the coexistence between a plurality of wireless communication modules sharing a single antenna is provided, including an antenna, first and second transceiving paths, and first and second wireless communications modules. The first transceiving path is coupled to the antenna. The second transceiving path is coupled to the first transceiving path. The first wireless communications module is coupled to the first transceiving path and transmits or receives a plurality of first wireless signals. The second wireless communications module is coupled to the second transceiving path and transmits or receives a plurality of second wireless signals, wherein signal strengths of the second wireless signals passing through the second transceiving path are attenuated by a certain level, and the attenuated second wireless signals are added to the first wireless signals when passing through the first transceiving path.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/224,107, filed on Jul. 9, 2009, the entirety of which is incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates generally to a system for the coexistence between a plurality of wireless communications modules, and more particularly, to a system for the coexistence between a plurality of wireless communications modules sharing a single antenna. 
         [0004]    2. Description of the Related Art 
         [0005]    As shown in  FIG. 1 , a cellular phone may connect to a wireless local area network (WLAN) via a WLAN module thereof and simultaneously communicate with a Bluetooth handset (or a Bluetooth car audio, or others) through a Bluetooth module thereof. WLAN is typically implemented as an extension to wired local area networks (LANs) inside a building and is able to provide the last few meters of connectivity between a wired network and mobile or fixed devices. WLAN is based on the IEEE 802.11 standard. Most WLAN may operate in the 2.4 GHz license-free frequency band and have throughput rates of up to 2 Mbps. The 802.11b standard introduces direct sequence mechanism and provides throughput rates of up to 11 Mbps. The 802.11g standard operates at a maximum raw data rate of 54 Mbps, or about 19 Mbps net throughput. As shown in  FIG. 1 , an access point (AP) is connected to a LAN by an Ethernet cable. The AP typically receives, buffers, and transmits data between the WLAN and the wired network infrastructure. The AP may support, on average, twenty devices and have a coverage varying from 20 meters in an area with obstacles (walls, stairways, elevators etc) and up to 100 meters in an area with clear line of sight. Bluetooth is an open wireless protocol for exchanging data over short distances from fixed and mobile devices, creating personal area networks (PANs). Voice over internet protocol (VoIP) data from the Internet may be received through WLAN connection and vice versa. A cellular phone may transmit voice data through an established PAN to the Bluetooth handset and receive speech signals captured by a microphone of the Bluetooth handset via the Bluetooth module. The cellular phone may transmit digital music through the established PAN to be played back in the Bluetooth handset. WLAN and Bluetooth both occupy a section of the 2.4 GHz Industrial, Scientific, and Medical (ISM) band, which is 83 MHz-wide. In light of cost issues as well as space used for component placement, modern electronic devices, such as cellular phones, Ultra-Mobile PCs (UMPCs) or others, are equipped with WLAN and Bluetooth modules sharing a single antenna instead of multiple antennas. 
         [0006]    Referring to  FIG. 2 , for example, Bluetooth uses Frequency Hopping Spread Spectrum (FHSS) and is allowed to hop between 79 different 1 MHz-wide channels in a Bluetooth spectrum. WLAN uses Direct Sequence Spread Spectrum (DSSS) instead of FHSS. Its carrier remains centered on one channel, which is 22 MHz-wide. When the WLAN module and the Bluetooth module are operating simultaneously in the same area, as shown in  FIG. 1 , the single WLAN channel, which is 22 MHz-wide, occupies the same frequency space as 22 out of 79 Bluetooth channels which are 1 MHz-wide. When a Bluetooth transmission occurs on a frequency band that falls within the frequency space occupied by an ongoing WLAN transmission, a certain level of interference may occur, depending on the signal strength thereof. Due to the fact that the WLAN module and Bluetooth module share the same spectrum and also share a single antenna, avoiding interference therebetween is required. 
         [0007]      FIG. 3  shows a diagram illustrating an operation conflict which may occur between a WLAN and a Bluetooth wireless communication service sharing a single antenna. In  FIG. 3 , the shared single antenna is switched between the WLAN and Bluetooth wireless communication services in a given time slot for transceiving data. Because the Bluetooth wireless communication service carries the audio data that requires real-time transmission, the Bluetooth wireless communication service has a higher priority over the WLAN wireless communication service. When a WLAN transceiving process takes place at the same time as a Bluetooth transceiving process, the WLAN transceiving process will be damaged. Referring to  FIG. 3  again, the WLAN receiving operation (Rx operation)  30  occurs at a time slot when the Bluetooth wireless communication service remains idle. Therefore, the Rx operation  30  is performed without interference and an acknowledgement (ACK) message  31  is sent to the WLAN AP (such as the AP in  FIG. 1 ) as a reply message after the Rx operation  30  is finished. Following the Rx operation  30 , another WLAN Rx operation  32  occurs. The Rx operation  32  is also performed without interference because the Bluetooth wireless communication service is in the idle state. However, an ACK message  33  in response to the Rx operation  32  can not be replied to the WLAN AP, as the ACK message  33  will occupy the same time slot of a Bluetooth transmitting operation (Tx operation). In this case, the Rx operation  32  would be deemed as failed. In light of the failure, the WLAN AP would re-perform the Rx operation  32  with a lower rate in an attempt to successfully receive the ACK message. However, the re-performed Rx operation  32  (denoted as  34 ), which has a prolonged operation period, will be more likely to overlap with the Bluetooth transceiving time slot. This causes a further retry of the Rx operation  32 , leading to a further decrement of the WLAN throughput. The performance degradation is caused by the inability of operating the WLAN and Bluetooth wireless communication services with a single antenna at the same time. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    In light of the previously described problems, there exists a need for a system, in which a plurality of wireless communication services may share a single antenna for simultaneous operations. 
         [0009]    An embodiment of the invention discloses a system for the coexistence between a plurality of wireless communication modules sharing a single antenna, comprising an antenna, a first transceiving path, a second transceiving path, a first wireless communications module and a second wireless communications module. The first transceiving path is coupled to the antenna. The second transceiving path is coupled to the first transceiving path. The first wireless communications module is coupled to the first transceiving path and transmits or receives a plurality of first wireless signals via the first transceiving path and the antenna. The second wireless communications module is coupled to the second transceiving path and transmits or receives a plurality of second wireless signals via the first and second transceiving paths and the antenna, wherein signal strengths of the second wireless signals passing through the second transceiving path are attenuated by a certain level, and the attenuated second wireless signals are added to the first wireless signals when passing through the first transceiving path. 
         [0010]    An embodiment of the invention discloses a system for the coexistence between a plurality of wireless communication modules sharing a single antenna, comprising an antenna, a first switching device, a directional coupler, a first wireless communications module and a second wireless communications module. The first switching device is configured to connect a first terminal connected to the antenna to a second terminal or a third terminal. The directional coupler has a first port connected to the second terminal, a second port connected to the first port via a first through path, a third port coupled to the first port and isolated from the second port, and a fourth port connected to the third port via a second through path, coupled to the second port, is isolated from the first port and connected to the third terminal. The first wireless communications module is configured to connect to the third port for transceiving wireless signals via the antenna. The second wireless communications module is configured to connect to the second port for transceiving wireless signals via the antenna. 
         [0011]    An embodiment of the invention discloses a system for the coexistence between a plurality of wireless communication modules sharing a single antenna, comprising an antenna, a diplexer, a Global Positioning System (GPS) module and a wireless communications system. The diplexer is configured to connect a first terminal connected to the antenna to a second terminal and a third terminal. The Global Positioning System (GPS) module is configured to connect to the second terminal for transceiving wireless signals via the second terminal and the antenna. The wireless communications system comprises a first transceiving path coupled to the antenna via the third terminal, a second transceiving path coupled to the first transceiving path, a first wireless communications module coupled to the first transceiving path and transmitting or receiving a plurality of first wireless signals via the first transceiving path and the antenna, and a second wireless communications module coupled to the second transceiving path and transmitting or receiving a plurality of second wireless signals via the first and second transceiving paths and the antenna, wherein signal strengths of the second wireless signals passing through the second transceiving path are attenuated by a certain level, and the attenuated second wireless signals are added to the first wireless signals when passing through the first transceiving path. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
           [0013]      FIG. 1  shows a cellular phone associating a WLAN via a WLAN module thereof as well as communicating with a Bluetooth handset through a Bluetooth module thereof; 
           [0014]      FIG. 2  shows a diagram of Bluetooth frequency Hopping; 
           [0015]      FIG. 3  shows a diagram illustrating an operation conflict between a WLAN and a Bluetooth wireless communication services sharing a single antenna; 
           [0016]      FIG. 4  shows an embodiment of a system for coexistence between a WLAN module and a Bluetooth module sharing a single antenna; 
           [0017]      FIG. 5A  shows a configuration of a switching device according to an embodiment of the invention; 
           [0018]      FIG. 5B  shows a configuration of a switching device according to another embodiment of the invention; 
           [0019]      FIG. 6  yet shows a configuration of a switching device according to another embodiment of the invention; 
           [0020]      FIG. 7A  shows a connection device implemented using an attenuator according to an embodiment of the invention; 
           [0021]      FIG. 7B  shows a connection device implemented using a directional coupler according to an embodiment of the invention; 
           [0022]      FIG. 7C  shows a connection device implemented using a divider according to an embodiment of the invention; 
           [0023]      FIG. 8A  shows a configuration of a connection device according to an embodiment of the invention; 
           [0024]      FIG. 8B  yet shows a configuration of a connection device according to an embodiment of the invention; 
           [0025]      FIG. 9  shows a flowchart for handling coexistence between WLAN and Bluetooth modules performed by the controller, according to an embodiment of the invention; 
           [0026]      FIG. 10A  shows a diagram illustrating a first case of possible WALN and Bluetooth operations within a time slot according to an embodiment of the invention; 
           [0027]      FIG. 10B  shows a diagram illustrating a second case of possible WALN and Bluetooth operations within a time slot according to an embodiment of the invention; 
           [0028]      FIG. 10C  shows a diagram illustrating a third case of possible WALN and Bluetooth operations within a time slot according to an embodiment of the invention; 
           [0029]      FIG. 10D  shows a diagram illustrating a fourth case of possible WALN and Bluetooth operations within a time slot according to an embodiment of the invention; 
           [0030]      FIG. 10E  shows a diagram illustrating a fifth case of possible WALN and Bluetooth operations within a time slot according to an embodiment of the invention; 
           [0031]      FIG. 11  shows another embodiment of a system for coexistence between a WLAN module and a Bluetooth module sharing a single antenna; 
           [0032]      FIG. 12  shows a flowchart for handling coexistence between WLAN and Bluetooth modules performed by the controller, according to another embodiment of the invention; 
           [0033]      FIG. 13  shows another embodiment of a system for coexistence between a WLAN module and a Bluetooth module sharing a single antenna; 
           [0034]      FIG. 14A  shows a configuration of a directional coupler according to an embodiment of the invention; 
           [0035]      FIG. 14B  yet shows a configuration of a directional coupler according to an embodiment of the invention; 
           [0036]      FIG. 14C  yet shows a configuration of a directional coupler according to an embodiment of the invention; 
           [0037]      FIG. 14D  yet shows a configuration of a directional coupler according to an embodiment of the invention; 
           [0038]      FIG. 15  shows a flowchart for handling coexistence between WLAN and Bluetooth modules performed by the controller, according to another embodiment of the invention; 
           [0039]      FIG. 16  shows another embodiment of a system for coexistence between a WLAN module and a Bluetooth module sharing a single antenna; 
           [0040]      FIG. 17  shows a flowchart for handling coexistence between WLAN and Bluetooth modules performed by the controller, according to another embodiment of the invention; 
           [0041]      FIG. 18  shows a diagram of a cellular phone connecting to a WLAN via a WLAN module as well as camping on a WiMAX base station through a WiMAX module; 
           [0042]      FIG. 19  shows a system for coexistence between a WLAN module and a WiMAX module sharing a single antenna according to an embodiment of the invention; 
           [0043]      FIG. 20  shows a system for coexistence between a Bluetooth module and a WiMAX module sharing a single antenna according to another embodiment of the invention; 
           [0044]      FIG. 21  shows a system for coexistence between a Bluetooth module and a WiMAX module sharing a single antenna according to another embodiment of the invention; 
           [0045]      FIG. 22  shows a system for coexistence between a Bluetooth module and a WiMAX module sharing a single antenna according to another embodiment of then invention; and 
           [0046]      FIG. 23  shows a system for coexistence between a Global Positioning System (GPS) and a subsystem sharing a single antenna according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0047]    The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
         [0048]      FIG. 4  shows an embodiment of a system for coexistence between a WLAN module and a Bluetooth module sharing a single antenna. The system  400  comprises an antenna  402 , switching devices  404  and  406 , a connection device  408 , a WLAN module  410 , a Bluetooth module  412  and a controller  414 . The controller  414  may operate as a packet traffic arbitrator (PTA) controller to receive Bluetooth traffic requests (labeled as BT_Req) and WLAN traffic requests (labeled as WLAN_Req) and determine whether a Bluetooth traffic request BT_Req has collided with a WLAN traffic request WLAN_Req within a time period. If a collision occurs, the PTA controller  414  may grant both of the requests or may grant only one of the requests while rejecting the other, depending on frequency bands, priorities, operation types (e.g. Tx/Rx operation), power levels or others. The PTA controller  414  then accordingly controls the switching device  404  and  406  by control signals (labeled as First_Ctrl and Second_Ctrl) to enable one or both of the WLAN module  410  and Bluetooth module  412  to transmit or receive data via the shared antenna  402 . The controller  414  may alternatively act as a traffic scheduler to collect Bluetooth schedules (labeled as BT_Sched) specifying Bluetooth Tx/Rx operations and WLAN schedules (labeled as WLAN_Sched) specifying WLAN Tx/Rx operations in a forthcoming time period, discover all fractional time periods having both Bluetooth and WLAN operations (also called collided time periods) and may cancel one of the Bluetooth and WLAN operations in the discovered time periods according to priorities, operation types, power levels or others. The traffic scheduler  414  then accordingly controls the switching device  404  and  406  by control signals (labeled as First_Ctrl and Second_Ctrl) to enable one or both of the WLAN module  410  and Bluetooth module  412  to transmit or receive data via the shared antenna  402 . Collision between upcoming Bluetooth and WLAN operations means that the operations are fully or partially overlapped with each other in a future time period. It is to be understood that the controller  414  may be integrated into the Bluetooth module  412  or the WLAN module  410  to reduce hardware cost. 
         [0049]    The switching device  404 , which consists of at least three terminals  50 ,  52  and  54  as shown in  FIG. 5A  or  5 B, is configured to connect the terminal  50  to the terminal  52  or  54 , as controlled by the controller  414 . The switching device  406 , which consists of four terminals  60 ,  62 ,  64  and  66  as shown in  FIG. 6 , is configured to connect the terminal  64  to the terminal  60  or  62 , or connect the terminal  66  to the terminal  60  and  62 , as controlled by the controller  414 . The connection device  408 , which consists of three terminals  70 ,  72  and  74  as shown in  FIG. 7A , is configured to connect the terminals  70  and  72  to form a transceiving path (through path), and connect the terminals  70  and  74  to form another transceiving path (coupled path), wherein the terminal  72  is isolated from the terminal  74  by substantially 20 dB, in which electrical signals passing through the path between terminals  70  and  72  are substantially attenuated by 6 or 10 dB. The switching devices  404  and  406 , connection device  408 , WLAN module  410 , Bluetooth module  412  and controller  414  may be disposed on a printed circuit board (PCB). As shown in  FIG. 5A , the switching device  404  may be implemented by a single-pole double-thrown (SPDT). Referring to  FIG. 5B , the switching device  404  may be alternatively implemented by a double-pole double-thrown (DPDT) switch with a terminal  56  coupled to or connected to an external node for impedance matching. The external node may be another antenna or a resistor (for example, a 50Ω resistor). In addition, the switching device  406  may be implemented by a DPDT switch as shown in  FIG. 6 . 
         [0050]    Referring to  FIG. 7A  again, the connection device  408  may contain an attenuator attenuating electrical signals passing through the terminals  70  and  74  by 20 dB. Referring to  FIG. 7B , the connection device  408  may alternatively contain a directional coupler, in which the terminals  70  and  72  are connected as a through path, terminal  74  and an external node  76  are connected as a through path, terminals  70  and  74  are coupled as a coupled path and terminals  72  and  74  are isolated, with an isolation loss of around 20-40 dB, wherein the through path is a direct or indirect through path and the external node may be connected to a resistor (for example, a 50Ω resistor). Note that the through path between terminals  70  and  72  may have a path loss between 0.6 dB and 0.8 dB substantially, whereas the coupled path between terminals  70  and  74  may have a path loss between 9.5 dB and 10.5 dB substantially. Or, the through path between terminals  70  and  72  may have a path loss between 1.1 dB and 1.4 dB substantially, whereas the coupled path between terminals  70  and  74  may have a path loss between 5.7 dB and 6.3 dB substantially. 
         [0051]    Referring to  FIG. 8A , by using two transmission lines set sufficiently close together such that electrical signals (or energy) directed from the terminal  70  (connected to a port called an input port) to the terminal  72  (connected to a port called a transmitted port) is coupled to the terminal  74  (connected to a port called a coupled port). Referring to  FIG. 8B , similarly, electrical signals (or energy) directed from the terminals  74  (connected to a port called an input port) to a transmitted port (such as port  76  in  FIG. 7B ) is coupled to the terminal  70  (connected to a port called a coupled port) and isolated from the terminal  72  (connected to a port called an isolated port), such that the coupled signals can be added to the electrical signals passing through the terminals  72  to  70 . 
         [0052]    As stated above, the connection device  408  may contain an attenuator ( FIG. 7A ) or a directional coupler ( FIG. 7B ). Alternatively, the connection device  408  may contain a power divider, as shown in  FIG. 7C . In  FIG. 7C , the terminals  72  and  74  are isolated and both ideally have a loss of 3 dB (3.5 dB in practice). Alternatively, the connection device  408  may contain a power splitter. The structure of the power splitter is similar to the power divider, but with different losses occurring between the output ports. For a power splitter, referring to  FIG. 7C , the losses of terminals  72  and  74  are different. For example, the terminal  72  may have a loss of 10 dB, whereas the terminal  74  may have a loss of 0.5 dB, or the terminal  72  may have a loss of 6 dB, whereas the terminal  74  may have a loss of 1 dB. Alternatively, the connection device  408  may be implemented by a PCB pad with an input port and two output ports, in which one of the output ports has a loss of NdB and another output port has a loss of 1 dB or smaller, as designed based on requirement. Note the power splitter may be implemented using a directional coupler, such as the one of  FIG. 7B , with the terminal  76  connected to a resistor for impedance matching and terminals  72  and  74  being isolated. With the power splitter implemented using a directional coupler as shown in  FIG. 7B , the terminal  72  may have a loss of 10 dB, whereas the terminal  74  may have a loss of 0.5 dB, or the terminal  72  may have a loss of 6 dB, whereas the terminal  74  may have a loss of 1 dB. 
         [0053]    Table 1 shows a combination of potential operations performed by the WLAN module  410  and the Bluetooth module  412 , according to the system  400  of  FIG. 4 : 
         [0000]    
       
         
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
             
             
               
                   
                   
               
               
                   
                 Operation Type 
               
             
          
           
               
                   
                 Case Type 
                 WLAN_Tx 
                 WLAN_Rx 
                 BT_Tx/BT_Rx 
               
               
                   
                   
               
               
                   
                 Case 1 
                 0 
                 0 
                 0 
               
               
                   
                 Case 2 
                 0 
                 0 
                 1 
               
               
                   
                 Case 3 
                 0 
                 1 
                 0 
               
               
                   
                 Case 4 
                 0 
                 1 
                 1 
               
               
                   
                 Case 5 
                 1 
                 0 
                 0 
               
               
                   
                 Case 6 
                 1 
                 0 
                 1 
               
               
                   
                 Case 7 
                 1 
                 1 
                 0 
               
               
                   
                 Case 8 
                 1 
                 1 
                 1 
               
               
                   
                   
               
             
          
         
       
     
         [0054]    In Table 1 above, “1” means TRUE, representing the existence of a corresponding operation, whereas “0” means FALSE, representing the absence of a corresponding operation. The situation for case 1 will not be discussed, as no operation exists. The cases 7 and 8, where the WLAN module  410  performs Tx and Rx operations simultaneously, is not permitted and therefore not discussed. The above cases will be discussed with references made to the flowchart as shown in  FIG. 9 . 
         [0055]      FIGS. 9A and 9B  show a flowchart for handling coexistence between WLAN and Bluetooth modules performed by the controller, according to an embodiment of the invention. The procedure begins at obtaining information regarding potential operation(s) that is/are going to be performed by the WLAN module  410  and Bluetooth module  412  in a forthcoming time period, which has/have been granted or scheduled by the controller  414 . Subsequently, a series of inspections with respect to the obtained information are accordingly performed to determine whether only one or both of the WLAN module  410  and Bluetooth module  412  occupy the time period, and determine whether the time period is occupied for a Tx and/or an Rx operation. Specifically, the information regarding potential operation(s) that is/are going to be performed by the WLAN module  410  and Bluetooth module  412  in a forthcoming time period is obtained (step S 900 ). Next, it is determined whether only the Bluetooth module  412  occupies the time period for an operation (Tx/Rx operation) (step S 902 ). If so, the controller  414  directs the first switching device  404  to connect the terminals  50  and  54  for the time period as shown in  FIG. 10A  (case 2) (step S 904 ), thereby enabling the Bluetooth Rx signals to be received by the Bluetooth module  412  from the single antenna  402  through terminals  50 ,  54 ,  70  and  72  in sequence, or enabling the Bluetooth Tx signals to be transmitted from the Bluetooth module  412  through terminals  72 ,  70 ,  54  and  50  in sequence to the single antenna  402 . Subsequent to step S 902 , if not, it is determined whether only the WLAN module  410  occupies the time period for a Tx operation (step S 906 ). If so, the controller  414  directs the first switching device  404  to connect the terminals  50  and  52  and directs the second switching device  406  to connect the terminals  60  and  64  for the time period as shown in  FIG. 10B  (case 5) (step S 908 ), thereby enabling the WLAN Tx signals to be transmitted from the WLAN module  410  through terminals  64 ,  60 ,  52  and  50  in sequence to the single antenna  402 . Subsequent to step S 906 , if not, it is determined whether only the WLAN module  410  occupies the time period for an Rx operation (step S 910 ). If so, the controller  414  directs the first switching device  404  to connect the terminals  50  and  52  and directs the second switching device  406  to connect the terminals  60  and  66  for the time period as shown in  FIG. 10C  (case 3) (step S 912 ), thereby enabling the WLAN Rx signals to be received by the WLAN module  410  from the single antenna  402  through terminals  50 ,  52 ,  60  and  66  in sequence. Subsequent to step S 910 , if not, it is determined whether the WLAN module  410  occupies the time period for a Tx operation (step S 914 ). If so, the controller  414  directs the first switching device  404  to connect the terminals  50  and  54  and directs the second switching device  406  to connect the terminals  62  and  64  for the time period when the time period is occupied by the WLAN module  410  and Bluetooth module  412  for a Bluetooth Rx or Tx operation as well as a WLAN Tx operation as shown in  FIG. 10D  (case 6) (step S 916 ), thereby enabling the WLAN Tx signals to be transmitted with a certain level of signal strength attenuation through terminals  64 ,  62 ,  74 ,  70 ,  54  and  50  in sequence from the WLAN module  410  to the antenna  402 , and enabling the Bluetooth Rx signals to be received by the Bluetooth module  412  from the antenna  402  through terminals  50 ,  54 ,  70  and  72  in sequence, or the Bluetooth Tx signals to be transmitted from the Bluetooth module  412  through terminals  72 ,  70 ,  54  and  50  in sequence to the antenna  402 . Subsequent to step S 914 , if not, it is determined whether the WLAN module  410  occupies the time period for an Rx operation (step S 918 ). If so, the controller  414  directs the first switching device  404  to connect the terminals  50  and  54  and directs the second switching device  406  to connect the terminals  62  and  66  for the time period when the time period is occupied by both the WLAN module  410  and Bluetooth module  412  for a Bluetooth Rx or Tx operation as well as a WLAN Rx operation as shown in  FIG. 10E  (case 4) (step S 920 ), thereby enabling the WLAN Rx signals to be received by the WLAN module  410  with a certain level of signal strength attenuation through terminals  50 ,  54 ,  70 ,  74 ,  62  and  66  in sequence from the antenna  402 , and enabling the Bluetooth Rx signals to be received by the Bluetooth module  412  from the antenna  402  through terminals  50 ,  54 ,  70  and  72  in sequence, or the Bluetooth Tx signals to be transmitted from the Bluetooth module  412  through terminals  72 ,  70 ,  54  and  50  in sequence to the antenna  402 . 
         [0056]    With the system  400  of  FIG. 4 , those skilled in the art may readily modify the hardware architecture thereof by separating the integrated port (labeled as BT_TRx of  FIG. 4 ) into two ports (labeled as BT_Tx and BT_Rx) and disposing a switching device  416  between the connection device  408  and the Bluetooth Module  412  for connecting a terminal  110  to a terminal  112  or  114  depending on the Bluetooth operation type (e.g. a Bluetooth Tx or Rx operation), as the system  1100  shown in  FIG. 11 . The switching device  416  may be implemented by an SPDT switch. The controller  414  then controls three switching devices  404 ,  406  and  416  by control signals (labeled as First_Ctrl, Second_Ctrl and Third_Ctrl) to enable the WLAN module  410  and Bluetooth module  412  to transmit or receive data via the shared antenna  402 . 
         [0057]    Table 2 shows a combination of potential operations performed by the WLAN module  410  and the Bluetooth module  412 , according to the system  1100  of  FIG. 11 : 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
                 TABLE 2 
               
             
             
               
                   
                   
               
               
                   
                 Case 
                 Operation Type 
                   
               
             
          
           
               
                   
                 Type 
                 WLAN_Tx 
                 WLAN_Rx 
                 BT_Tx 
                 BT_Rx 
               
               
                   
                   
               
               
                   
                 Case 1 
                 0 
                 0 
                 0 
                 0 
               
               
                   
                 Case 2 
                 0 
                 0 
                 0 
                 1 
               
               
                   
                 Case 3 
                 0 
                 0 
                 1 
                 0 
               
               
                   
                 Case 4 
                 0 
                 0 
                 1 
                 1 
               
               
                   
                 Case 5 
                 0 
                 1 
                 0 
                 0 
               
               
                   
                 Case 6 
                 0 
                 1 
                 0 
                 1 
               
               
                   
                 Case 7 
                 0 
                 1 
                 1 
                 0 
               
               
                   
                 Case 8 
                 0 
                 1 
                 1 
                 1 
               
               
                   
                 Case 9 
                 1 
                 0 
                 0 
                 0 
               
               
                   
                 Case 10 
                 1 
                 0 
                 0 
                 1 
               
               
                   
                 Case 11 
                 1 
                 0 
                 1 
                 0 
               
               
                   
                 Case 12 
                 1 
                 0 
                 1 
                 1 
               
               
                   
                 Case 13 
                 1 
                 1 
                 0 
                 0 
               
               
                   
                 Case 14 
                 1 
                 1 
                 0 
                 1 
               
               
                   
                 Case 15 
                 1 
                 1 
                 1 
                 0 
               
               
                   
                 Case 16 
                 1 
                 1 
                 1 
                 1 
               
               
                   
                   
               
             
          
         
       
     
         [0058]    In Table 2 above, case 1 is not discussed as no operation exists. The cases 13 to 16, where the WLAN module  410  performs Tx and Rx operations simultaneously, is not permitted in the system  1100  and therefore not discussed. Based on the same reason, the cases 4, 8 and 12, where the Bluetooth module  412  performs Tx and Rx operations simultaneously, are also not discussed. The other cases will be discussed with references made to the flowchart in  FIG. 12 . 
         [0059]    According to the modified architecture shown in  FIG. 11 , those skilled in the art may readily modify the control flow of  FIGS. 9A and 9B  to that of  FIGS. 12A to 12C  by incorporating more inspections and controls with respect to the newly added switching device  416 . In  FIG. 12 , the procedure begins at obtaining information regarding potential operation(s) that is/are going to be performed by the WLAN module  410  and Bluetooth module  412  in a forthcoming time period, which has/have been granted or scheduled by the controller  414  (step S 1200 ). Next, it is determined whether only the Bluetooth module  412  occupies the time period for a Tx operation (step S 1202 ). If so, the controller  414  directs the switching device  404  to connect the terminals  50  and  54  and directs the third switching device  416  to connect the terminals  110  and  112  for the time period when the time period is occupied by only the Bluetooth module  412  for a Tx operation (case 3) (step S 1204 ), thereby enabling the Tx signals to be transmitted from the Bluetooth module  412  through terminals  112 ,  110 ,  72 ,  70 ,  54  and  50  in sequence to the shared antenna  402 . Subsequent to step  1202 , if not, it is determined whether only the Bluetooth module  412  occupies the time period for an Rx operation (step S 1206 ). If so, the controller  414  directs the switching device  404  to connect the terminals  50  and  54  and directs the switching device  416  to connect terminals  110  and  114  for the time period when the time period is occupied by only the Bluetooth module  412  for an Rx operation (case 2) (step S 1208 ), thereby enabling the Bluetooth Rx signals to be received by the Bluetooth module  412  from the shared antenna  402  through terminals  50 ,  54 ,  70 ,  72 ,  110  and  114  in sequence. Subsequent to step  1206 , if not, it is determined whether only WLAN module  410  occupies the time period for a Tx operation (step S 1210 ). If so, the controller  414  directs the switching device  404  to connect the terminals  50  and  52  and directs the switching device  406  to connect the terminals  60  and  64  for the time period when the time period is occupied by only WLAN module  410  for a Tx operation (case 9) (step S 1212 ), thereby enabling the WLAN Tx signals to be transmitted from the WLAN module  410  through terminals  64 ,  60 ,  52  and  50  in sequence to the shared antenna  402 .—Subsequent to step  1210 , if not, it is determined whether only WLAN module  410  occupies the time period for an Rx operation (step S 1214 ). If so, the controller  414  directs the switching device  404  to connect the terminals  50  and  52  and directs the switching device  406  to connect the terminals  60  and  66  for the time period when the time period is occupied by only WLAN module  410  for an Rx operation (case 5) (step S 1216 ), thereby enabling the WLAN Rx signals to be received by the WLAN module  410  from the shared antenna  402  through terminals  50 ,  52 ,  60  and  66  in sequence. Subsequent to step  1214 , if not, it is determined whether both the WLAN module  410  and the Bluetooth module  412  occupy the time period for the Tx operations (step S 1218 ). If so, the controller  414  directs the switching device  404  to connect the terminals  50  and  54 , directs the switching device  406  to connect the terminals  62  and  64 , and directs the switching device  416  to connect the terminals  110  and  112  for the time period when the time period is occupied by the Bluetooth module  412  for a Bluetooth Tx operation and the WLAN modules  410  for a WLAN Tx operation (case 11) (step S 1220 ), thereby enabling the WLAN Tx signals to be transmitted with a certain level of signal strength attenuation through terminals  64 ,  62 ,  74 ,  70 ,  54  and  50  in sequence from the WLAN module  410  to the shard antenna  402 , and enabling the Bluetooth Tx signals to be transmitted from the Bluetooth module  412  through terminals  112 ,  110 ,  72 ,  70 ,  54  and  50  in sequence to the antenna  402 . Subsequent to step  1218 , if not, it is determined whether the WLAN module  410  and the Bluetooth module  412  occupy the time period for the Tx and Rx operations, respectively (step S 1222 ). If so, the controller  414  directs the switching device  404  to connect the terminals  50  and  54 , directs the switching device  406  to connect the terminals  62  and  64 , and directs the switching device  416  to connect the terminals  110  and  114  for the time period when the time period is occupied by the WLAN module  410  for a WLAN Tx operation and the Bluetooth module  412  for a Bluetooth Rx operation (case 10) (step S 1224 ), thereby enabling the WLAN Tx signals to be transmitted with a certain level of signal strength attenuation through terminals  64 ,  62 ,  74 ,  70 ,  54  and  50  in sequence from the WLAN module  410  to the shared antenna  402 , and enabling the Bluetooth Rx signals to be received by the Bluetooth module  412  from the shared antenna  402  through terminals  50 ,  54 ,  70 ,  72 ,  110  and  114  in sequence. Subsequent to step  1222 , if not, it is determined whether both the WLAN module  410  and the Bluetooth module  412  occupy the time period for Rx operations (step S 1226 ). If so, the controller  414  directs the switching device  404  to connect the terminals  50  and  54 , directs the second switching device  406  to connect the terminals  62  and  66 , and directs the third switching device  416  to connect the terminals  110  and  114  for the time period when the time period is occupied by the WLAN module  410  for a WLAN Rx operation and the Bluetooth module  412  for a Bluetooth Rx operation (case 6) (step S 1228 ), thereby enabling the WLAN Rx signals to be received by the WLAN module  410  with a certain level of signal strength attenuation through terminals  50 ,  54 ,  70 ,  74 ,  62  and  66  in sequence from the shared antenna  402 , and enabling the Bluetooth Rx signals to be received by the Bluetooth module  412  from the shared antenna  402  through terminals  50 ,  54 ,  70 ,  72 ,  110  and  114  in sequence from the shared antenna  402 . Subsequent to step  1226 , if not, it is determined whether the WLAN module  410  and the Bluetooth module  412  occupy the time period for Rx and Tx operations, respectively (step S 1230 ). If so, the controller  414  directs the switching device  404  to connect the terminals  50  and  54 , directs the switching device  406  to connect the terminals  62  and  66 , and directs the switching device  416  to connect the terminals  110  and  112  for the time period when the time period is occupied by the WLAN module  410  for a WLAN Rx operation and the Bluetooth module  412  for a Bluetooth Tx operation (case 7) (step S 1232 ), thereby enabling the WLAN Rx signals to be received by the WLAN module  410  with a certain level of signal strength attenuation through terminals  50 ,  54 ,  70 ,  74 ,  62  and  66  in sequence from the shared antenna  402 , and enabling the Bluetooth Tx signals to be transmitted from the Bluetooth module  412  through terminals  112 ,  110 ,  72 ,  70 ,  54  and  50  in sequence to the shared antenna  402 . 
         [0060]      FIG. 13  shows another embodiment of a system for coexistence between a WLAN module and a Bluetooth module sharing a single antenna. Similar to the system  400  of  FIG. 4 , the system  1300  herein comprises an antenna  402 , a switching device  404 , a WLAN module  410 , a Bluetooth module  412  and a controller  414 . The same numerals in  FIG. 13  represent similar elements of  FIG. 4  without departing from the spirit of the invention, references of the WLAN module  410 , Bluetooth module  412 , switching device  404  and controller  414  may be made to the descriptions of  FIG. 4  for brevity. A switching device  418  is configured to connect a terminal  130  to a terminal  132  or  134  as controlled by the controller  414 , and may be implemented by an SPDT switch. The directional coupler  420  consists of four terminals  136 ,  138 ,  140  and  142  which are connected to terminals  52 , BT_TRx,  130  and  54  respectively, thereby enabling the terminals  54  and BT_TRx to be connected via a first through path, terminals  52  and  130  to be connected via a second through path, BT_TRx and  130  to be isolated (with substantially 20 dB of isolation or more), terminal  54  and  52  to be isolated (with substantially 20 dB of isolation or more), terminals BT_TRx and  52  to be coupled as a first coupled path and terminals  130  and  54  to be coupled as a second coupled path, wherein the first and second through paths are direct or indirect through paths. The switching devices  404  and  418 , directional coupler  420 , WLAN module  410 , Bluetooth module  412  and controller  414  may be disposed on a PCB. Note the first and second through paths may have a loss of 0.5 dB substantially, whereas the first and second coupled paths may have a loss of 10 dB substantially, or the first and second through paths may have a loss of 1 dB substantially, whereas the first and second coupled paths may have a loss of 6 dB substantially. 
         [0061]    Referring to  FIG. 14A , by using two transmission lines set sufficiently close together, electrical signals (or energy) directed from the terminal BT_TRx (connected to the port  138  called an input port) to terminal  54  (connected to the port  142  called a transmitted port) is coupled to the terminal  52  (connected to the port  136  called a coupled port) and is isolated from the terminal  130  (connected to the port  140  called an isolated port), such that the coupled signals can be added to electrical signals passing through the terminals  130  to  52 . Referring to  FIG. 14B , by using two transmission lines set sufficiently close together, electrical signals directed from the terminals  54  (connected to the port  142  called an input port) to terminal BT_TRx (connected to the port  138  called a transmitted port) is coupled to the terminal  130  (connected to the port  140  called a coupled port) and isolated from the terminal  52  (connected to the port  136  called an isolated port), such that the coupled signals can be added to electrical signals passing through the terminals  52  to  130 . Referring to  FIG. 14C , similarly, electrical signals directed from terminals  130  to  52  is coupled to the terminal  54  and can be added to electrical signals passing through the terminals BT_TRx to  54 . Referring to  FIG. 14D , similarly, electrical signals passing through the terminals  52  to  130  is coupled the terminal BT_TRx and can be added to electrical signals passing through the terminals  54  to BT_TRx. 
         [0062]    Table 3 shows a combination of potential operations performed by the WLAN module  410  and the Bluetooth module  412 , according to the system  1300  in  FIG. 13 : 
         [0000]    
       
         
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
             
             
               
                   
                   
               
               
                   
                 Operation Type 
               
             
          
           
               
                   
                   
                   
                   
                 Signal Strength 
               
               
                 Case 
                   
                   
                   
                 Attenuation For 
               
               
                 Type 
                 WLAN_Tx 
                 WLAN_Rx 
                 BT_Tx/BT_Rx 
                 WLAN or BT 
               
               
                   
               
               
                 Case 1 
                 0 
                 0 
                 0 
                 None 
               
               
                 Case 2 
                 0 
                 0 
                 1 
                 None 
               
               
                 Case 3 
                 0 
                 1 
                 0 
                 None 
               
               
                 Case 
                 0 
                 1 
                 1 
                 WLAN 
               
               
                 4A 
               
               
                 Case 
                   
                   
                   
                 BT 
               
               
                 4B 
               
               
                 Case 5 
                 1 
                 0 
                 0 
                 None 
               
               
                 Case 
                 1 
                 0 
                 1 
                 WLAN 
               
               
                 6A 
               
               
                 Case 
                   
                   
                   
                 BT 
               
               
                 6B 
               
               
                 Case 7 
                 1 
                 1 
                 0 
                 None 
               
               
                 Case 8 
                 1 
                 1 
                 1 
                 None 
               
               
                   
               
             
          
         
       
     
         [0063]    In Table 3 above, the case 1 is not discussed as no operation exists. The cases 7 and 8, where the WLAN module  410  performs Tx and Rx operations simultaneously, is not permitted in the system  400  and therefore not discussed. The other cases will be discussed with references made to the flowchart in  FIG. 15 . 
         [0064]    According to the hardware architecture shown in  FIG. 13 , those skilled in the art may readily modify the control flow of  FIG. 9  to that of  FIG. 15  by incorporating similar but different inspections and controlling methods with respect to the switching devices  404  and  418 . In  FIG. 15 , the procedure begins at obtaining information regarding all potential operation(s) that is/are going to be performed by the WLAN module  410  and Bluetooth module  412  in a forthcoming time period, which has/have been granted or scheduled by the controller  414  (step S 1500 ). Next it is determined whether only the Bluetooth module  412  occupies the time period for a Tx or Rx operation (step S 1502 ). If so, the controller  414  directs the switching device  404  to connect terminals  50  and  54  for the time period as shown in  FIG. 10A  (case 2) (step S 1504 ), thereby enabling the Bluetooth Rx signals to be received by the Bluetooth module  412  from the shared antenna  402  through terminals  50  and  54 , and ports  142  and  138  in sequence, or enabling the Bluetooth Tx signals to be transmitted from the Bluetooth module  412  through ports  138  and  142 , and terminals  54  and  50  in sequence to the shared antenna  402 . Subsequent to step S 1502 , if not, it is determined whether only the WLAN module  410  occupies the time period for a Tx operation (step S 1506 ). If so, the controller  414  directs the switching device  404  to connect terminals  50  and  52  and directs the switching device  418  to connect terminals  130  and  132  for the time period as shown in  FIG. 10B  (case 5) (step S 1508 ), thereby enabling the WLAN Tx signals to be transmitted from the WLAN module  410  through terminals  132  and  130 , ports  140  and  136 , and terminals  52  and  50  in sequence to the shared antenna  402 . Subsequent to step S 1506 , if not, it is determined whether only the WLAN module  410  occupies the time period for an Rx operation (step S 1510 ). If so, the controller  414  directs the switching device  404  to connect terminals  50  and  52  and directs the switching device  418  to connect terminals  130  and  134  for the time period as shown in  FIG. 10C  (case 3) (step S 1512 ), thereby enabling the WLAN Rx signals to be received by the WLAN module  410  from the shared antenna  402  through terminals  50  and  52 , ports  136  and  140 , and terminals  130  and  134  in sequence. Subsequent to step S 1510 , if not, it is determined whether signal strength from/to the WLAN module  410  exceeds that from/to Bluetooth module  412  by a predetermined threshold (step S 1514 ). If the signal strength of the WLAN module  410  exceeds the signal strength of the Bluetooth module  412  by the predetermined threshold, it is determined whether the WLAN module  410  occupies the time period for a Tx or Rx operation (step S 1516 ). If a WLAN Tx operation is performed, the controller  414  directs the switching device  404  to connect terminals  50  and  54  and directs the switching device  418  to connect terminals  130  and  132  for the time period when the time period is occupied by the Bluetooth module  412  for an Rx or Tx operation as well as by the WLAN module  410  for a Tx operation as shown in  FIG. 10D  (case 6A) (step S 1518 ), thereby enabling the WLAN Tx signals to be transmitted with a certain level of signal strength attenuation through terminals  132  and  130 , ports  140  and  142 , and terminals  54  and  50  in sequence from the WLAN module  410  to the shared antenna  402 , and enabling the Bluetooth Tx signals to be transmitted from the Bluetooth module  412  through ports  138  and  142 , and terminals  54  and  50  in sequence to the shared antenna  402 , or enabling the Bluetooth Rx signals to be received by the WLAN module  412  from the shared antenna  402  through terminals  50  and  54 , and ports  142  and  138  in sequence. Subsequent to step S 1516 , if a WLAN Rx operation is performed, the controller  414  directs the switching device  404  to connect terminals  50  and  54  and directs the switching device  418  to connect terminals  130  and  134  for the time period when the time period is occupied by the Bluetooth module  412  for an Rx or Tx operation as well as by the WLAN module  410  for an Rx operation as shown in  FIG. 10E  (case 4A) (step S 1520 ), thereby enabling the WLAN Rx signals to be received by the WLAN module  410  with a certain level of signal strength attenuation through from the shared antenna  402  terminals  50  and  54 , ports  142  and  140 , and terminals  130  and  134  in sequence, and enabling the Bluetooth Tx signals to be transmitted from the Bluetooth module  412  through ports  138  and  142 , and terminals  54  and  50  in sequence to the shared antenna  402 , or enabling the Bluetooth Rx signals to be received by the WLAN module  412  from the shared antenna  402  through the terminals  50  and  54 , and ports  142  and  138  in sequence. Subsequent to step S 1514 , if signal strength from/to the WLAN module  410  does not exceed signal strength from/to the Bluetooth module  412  by the predetermined threshold, it is determined whether the WLAN module  410  occupies the time period for a Tx or Rx operation (step S 1522 ). If a WLAN Tx operation is performed, the controller  414  directs the switching device  404  to connect terminals  50  and  52  and directs the switching device  418  to connect terminals  130  and  132  for the time period when the time period is occupied by the Bluetooth module  412  for an Rx or Tx operation as well as by the WLAN module  410  for a Tx operation as shown in  FIG. 10D  (case 6B) (step S 1524 ), thereby enabling the WLAN Tx signals to be transmitted from the WLAN module  410  through terminals  132  and  130 , ports  140  and  136 , and terminals  52  and  50  in sequence to the shard antenna  402 , and enabling the Bluetooth Tx signals to be transmitted with a certain level of signal strength attenuation through ports  138 , and  136 , and terminals  52  and  50  in sequence from the Bluetooth module  412  to the shared antenna  402 , or enabling the Bluetooth Rx signals to be received by the Bluetooth module  412  with a certain level of signal strength attenuation through terminals  50  and  52 , and ports  136  and  138  in sequence from the shared antenna  402 . Subsequent to step S 1522 , if a WLAN Rx operation is performed, the controller  414  directs the switching device  404  to connect terminals  50  and  52  and directs the switching device  418  to connect terminals  130  and  134  for the time period when the time period is occupied by the Bluetooth module  412  for an Rx or Tx operation as well as by the WLAN module  410  for an Rx operation as shown in  FIG. 10E  (case 4B) (step S 1526 ), thereby enabling the WLAN Rx signals to be received by the WLAN module  410  from the shared antenna  402  through terminals  50  and  52 , ports  136  and  140 , and terminals  130  and  134  in sequence, and enabling the Bluetooth Tx signals to be transmitted with a certain level of signal strength attenuation through ports  138  and  136 , and terminals  52  and  50  in sequence from the Bluetooth module  412  to the shared antenna  402 , or enabling the Bluetooth Rx signals to be received with a certain level of signal strength attenuation through terminals  50  and  52 , and ports  136  and  138  in sequence from the shared antenna  402  to the Bluetooth module  412 . 
         [0065]    Note that in the embodiment of  FIG. 13 , when the operation type of the WLAN module  410  is an Rx operation and the operation type of the Bluetooth module  412  is a Tx operation and the Tx power level of the Bluetooth module  412  is higher than the Rx power level of the WLAN module  410  by a certain level, the controller  414  may control the switching device  404  to connect the terminals  50  and  52  such that the WLAN Rx signal is received via the through path between ports  136  and  140 , and the Bluetooth Tx signal is transmitted via the coupled path between ports  136  and  138  with greater loss. This is to prevent the Bluetooth Tx operation from interfering with the WLAN Rx operation. Similarly, when the operation type of the WLAN module  410  is a Tx operation and the operation type of the Bluetooth module  412  is an Rx operation and the Tx power level of the WLAN module  410  is higher than the Rx power level of the Bluetooth module  412  by a certain level, the controller  414  may control the switching device  404  to connect the terminals  50  and  54  such that the WLAN Tx signal is transmitted via the coupled path between ports  140  and  142  with greater loss, and the Bluetooth Rx signal is received via the through path between ports  138  and  142 . 
         [0066]    With the system  1300  of  FIG. 13 , those skilled in the art may readily modify the hardware architecture of  FIG. 13  to that of  FIG. 16  by separating the integrated port (labeled as BT_TRx of  FIG. 13 ) into two ports (labeled as BT_Tx and BT_Rx of  FIG. 16 ) and disposing a switching device  422  between the directional coupler  420  and the Bluetooth module  412  for connecting a terminal  160  to a terminal  162  or  164  depending on the Bluetooth operation type (e.g. a Bluetooth Tx or Rx operation). The switching device  422  may be implemented by an SPDT switch. The controller  414  then controls three switching devices  404 ,  418  and  422  by control signals (labeled as First_Ctrl, Fourth_Ctrl and Fifth_Ctrl) to enable the WLAN module  410  and Bluetooth module  412  to transmit or receive data via the shared antenna  402 . 
         [0067]    Table 4 shows a combination of potential operations performed by the WLAN module  410  and the Bluetooth module  412 , according to the system  1600  shown of  FIG. 16 : 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
             
           
               
                   
                 TABLE 4 
               
             
             
               
                   
                   
               
               
                   
                 Operation Type 
               
             
          
           
               
                   
                   
                   
                   
                   
                 Signal 
               
               
                   
                   
                   
                   
                   
                 Strength 
               
               
                   
                   
                   
                   
                   
                 Attenuation 
               
               
                   
                   
                   
                   
                   
                 For WLAN 
               
               
                 Case Type 
                 WLAN_Tx 
                 WLAN_Rx 
                 BT_Tx 
                 BT_Rx 
                 or BT 
               
               
                   
               
               
                 Case 1 
                 0 
                 0 
                 0 
                 0 
                 None 
               
               
                 Case 2 
                 0 
                 0 
                 0 
                 1 
                 None 
               
               
                 Case 3 
                 0 
                 0 
                 1 
                 0 
                 None 
               
               
                 Case 4 
                 0 
                 0 
                 1 
                 1 
                 None 
               
               
                 Case 5 
                 0 
                 1 
                 0 
                 0 
                 None 
               
               
                 Case 6A 
                 0 
                 1 
                 0 
                 1 
                 WLAN 
               
               
                 Case 6B 
                   
                   
                   
                   
                 BT 
               
               
                 Case 7A 
                 0 
                 1 
                 1 
                 0 
                 WLAN 
               
               
                 Case 7B 
                   
                   
                   
                   
                 BT 
               
               
                 Case 8 
                 0 
                 1 
                 1 
                 1 
                 None 
               
               
                 Case 9 
                 1 
                 0 
                 0 
                 0 
                 None 
               
               
                 Case 10A 
                 1 
                 0 
                 0 
                 1 
                 WLAN 
               
               
                 Case 10B 
                   
                   
                   
                   
                 BT 
               
               
                 Case 11A 
                 1 
                 0 
                 1 
                 0 
                 WLAN 
               
               
                 Case 11B 
                   
                   
                   
                   
                 BT 
               
               
                 Case 12 
                 1 
                 0 
                 1 
                 1 
                 None 
               
               
                 Case 13 
                 1 
                 1 
                 0 
                 0 
                 None 
               
               
                 Case 14 
                 1 
                 1 
                 0 
                 1 
                 None 
               
               
                 Case 15 
                 1 
                 1 
                 1 
                 0 
                 None 
               
               
                 Case 16 
                 1 
                 1 
                 1 
                 1 
                 None 
               
               
                   
               
             
          
         
       
     
         [0068]    In Table 4 above, the case 1 is not discussed, as no operation exists. The cases 13 to 16, where the WLAN module  410  performs Tx and Rx operations simultaneously, is not permitted in the system  1600  and therefore not discussed. Based on the same reason, the cases 4, 8 and 12, where the Bluetooth module  412  performs Tx and Rx operations simultaneously, are also not discussed. The other cases will be discussed with references made to the flowchart in  FIG. 17 . 
         [0069]    According to the hardware architecture shown in  FIG. 16 , those skilled in the art may readily modify the control flow of  FIG. 15  to that of  FIG. 17  by incorporating similar but different inspections and controls with respect to the switching devices  404 ,  418  and  422 . Details of the control flow in  FIG. 17  can be obtained with references made to the descriptions with respect to  FIGS. 11 and 13 , and are therefore not described hereinafter for brevity. 
         [0070]    The descriptions so far have been made for systems for the coexistence between WLAN and Bluetooth wireless communication services according to several embodiments of the invention. The conception of coexistence between wireless communication systems, however, may also apply to Worldwide Interoperability for Microwave Access (WiMAX) wireless communication service. 
         [0071]    IEEE 802.16 (WiMAX) represents a standard for wireless broadband access, and is designed for outdoor, long-range and carrier-class applications with high throughput. Referring to  FIG. 18 , a cellular phone may associate a WLAN via a WLAN module and further camp on a WiMAX base station through a WiMAX module, where a WLAN access point is deployed inside an 802.16 cell. The 802.16 standard supports both licensed and license-exempt spectrums, where an 802.16a specifies an operation in the 2-10 GHz band, supporting raw bit rates of up to 75 Mb/s with variable channel bandwidths of 1.5 MHz to 20 MHz. The WiMAX module may use Orthogonal Frequency-Division Multiplexing (OFDM) mechanism with 20 MHz-wide bandwidth. New interference challenges as the new protocol operates is faced over several frequency bands (defined by ‘profiles” in WiMAX terminology), with the most common being 2.2-2.4 GHz and 2.5-2.7 GHz. The frequency separation, although greater than that between Bluetooth and WiFi, is still not enough to prevent coexistence problems. Typically, the interference can be solved by separating WiMAX and WLAN transceiving operations into different time slots. That is, the single antenna can be occupied by only one of the WiMAX and WLAN modules within a time period for a transmission or a receiving operation (Tx or Rx). By using the time division mechanism, however, maintaining high quality speech or data transmission for a WiMAX wireless communication service would result in limited data throughput for a WLAN wireless communication service, and vice versa. 
         [0072]      FIG. 19  shows a system for coexistence between a WLAN module and a WiMAX module sharing a single antenna according to an embodiment of the invention, which is modified according to the architecture of  FIG. 11 . The controller  414  may operate as a PTA controller or a traffic scheduler as mentioned above, and control the switching devices  404 ,  406  and  416  by control signals (labeled as First_Ctrl, Second_Ctrl and Third_Ctrl) to enable the WLAN module  410  and WiMAX module  424  to transmit or receive data via the shared antenna  402  based on the PTA or scheduled results. In addition, a filter  426  is coupled between terminals  74  and  62 , and filters out unwanted frequencies, allowing only the WLAN frequency range (band of frequencies) to reach the output side. In general, the WALN frequency band is 2.4 to 2.5 GHz. The filter  426  may be a bandpass filter. A filter  428  is coupled between terminals  72  and  110 , allowing all frequency bands other than the WLAN frequency band to reach the output side. The filter  428  may be a notch filter. 
         [0073]    Without departing from the spirit of the invention, an embodiment of a method for handling coexistence between a Bluetooth module  412  and a WiMAX module  424  performed by the controller  414  can be devised with relevant modifications according to the architecture of  FIG. 19  and the flowchart of  FIG. 12 . 
         [0074]    In addition,  FIG. 20  shows another embodiment of a system for coexistence between a Bluetooth module and a WiMAX module sharing a single antenna, which is modified according to the architecture of  FIG. 16 . The controller  414  may operate as a PTA controller or a traffic scheduler as mentioned above, and control the switching devices  404 ,  418  and  422  by control signals (labeled as First_Ctrl, Fourth_Ctrl and Fifth_Ctrl) to enable the Bluetooth module  412  and WiMAX module  424  to transmit or receive data via the shared antenna  402  based on the PTA or scheduled results. In addition, the filter  426  is coupled between the port  140  of the directional coupler  420  and the terminal  130 , and the filter  428  is coupled between the port  138  of the directional coupler  420  and the terminal  160 . 
         [0075]    Without departing from the spirit of the invention, an embodiment of a method for handling coexistence between a WLAN module and a WiMAX module performed by the controller can be devised with relevant modifications according to the architecture of  FIG. 20  and the control flow of  FIG. 17 . 
         [0076]    Similarly, when a WiMAX transmission occurs on a frequency that falls within the frequency space occupied by an ongoing Bluetooth transmission, a certain level of interference may occur, depending on the signal strength thereof. Because both the Bluetooth module  412  and WiMAX module  424  share the same spectrum and share a single antenna, avoiding interference therebetween is required. Typically, the interference can be solved by separating WiMAX and Bluetooth transceiving operations into different time slots. That is, the single antenna can be occupied by only one of the WiMAX and Bluetooth modules within a time period for a transmission or a receiving operation. By using the time division mechanism, however, maintaining high quality speech or data transmission for a PAN would result in limited data throughput for a WiMAX wireless communication service, and vice versa. 
         [0077]      FIG. 21  shows another embodiment of a system for coexistence between a Bluetooth module and a WiMAX module sharing a single antenna, which is modified according to the architecture of  FIG. 11 . The controller  414  may operate as a PTA controller or a traffic scheduler as mentioned above, and control the switching devices  404 ,  406  and  416  by control signals (labeled as First_Ctrl, Second_Ctrl and Third_Ctrl) to enable the Bluetooth module  412  and WiMAX module  424  to transmit or receive data via the shared antenna  402  based on the PTA or scheduled results. In addition, a filter  430  is coupled between terminals  72  and  160 , and filters out unwanted frequencies, allowing only the Bluetooth frequency range (band of frequencies) to reach the output side. Similar to the WALN frequency band, the Bluetooth frequency band is 2.4 to 2.5 GHz. The filter  430  may be a bandpass filter. A filter  432  is coupled between terminals  74  and  62 , allowing all frequency bands other than the Bluetooth frequency band to reach the output side. The filter  432  may be a notch filter. 
         [0078]    Without departing from the spirit of the invention, an embodiment of a method for handling coexistence between Bluetooth module  412  and WiMAX module  424  performed by the controller  414  can be devised with relevant modifications according to the architecture of  FIG. 21  and the control flow of  FIG. 17 . 
         [0079]      FIG. 22  shows another embodiment of a system for coexistence between a Bluetooth module and a WiMAX module sharing a single antenna, which is modified according to the architecture of  FIG. 16 . The controller  414  may operate as a PTA controller or a traffic scheduler as mentioned above, and control the switching devices  404 ,  416  and  418  by control signals (labeled as First_Ctrl, Fourth_Ctrl and Fifth_Ctrl) to enable the Bluetooth module  412  and WiMAX module  424  to transmit or receive data via the shared antenna  402  based on the PTA or scheduled results. In addition, the filter  432  is coupled between the port  140  of the directional coupler  420  and the terminal  130 , and the filter  430  is coupled between the port  138  of the directional coupler  420  and the terminal  160 . 
         [0080]    Without departing from the spirit of the invention, an embodiment of a method for handling coexistence between Bluetooth module  412  and WiMAX module  424  performed by the controller can be devised with relevant modifications according to the architecture of  FIG. 22  and the control flow of  FIG. 17 . 
         [0081]      FIG. 23  shows another embodiment of a system for coexistence between a Global Positioning System (GPS) and a subsystem sharing a single antenna, with the subsystem being any one of the systems  400 ,  1100 ,  1300 ,  1600 ,  1900 ,  2000 ,  2100  and  2200  excluding the antenna  402 . The system  2300  comprises an antenna  402 , a diplexer  434 , a GPS module and a subsystem  438 . The diplexer  434  is configured to connect a terminal  230  to both terminals  232  and  234  such that the GPS signals (Tx or Rx signal) are transmitted to/received from the shared antenna  402  via the diplexer  434 , and the wireless signals of the subsystem  438  (Tx or Rx signal) are simultaneously transmitted to/received from the shared antenna  402  via the diplexer  434 . 
         [0082]    While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.