Abstract:
A multimode wireless communication device includes a first radio section operably to convert outbound analog baseband signals into first outbound RF signals and to convert first inbound RF signals into inbound analog baseband signals when the wireless communication device is in a first mode of operation and a second radio section that performs similar functions in a second mode of operation. A diplexer section includes a first diplexer for coupling to a first antenna, and a second diplexer for coupling to a second antenna, and that selectively couples the first radio section to one of the first antenna and the second antenna, and that selectively couples the second radio section to one of the first antenna and the second antenna. First and second T/R switches are coupled to the first and second diplexers and to respectively, to the first and second radio sections.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present U.S. Utility patent application claims priority under 35 USC §121 as a divisional of U.S. patent application Ser. No. 11/643,170, entitled, “MULTIMODE WIRELESS COMMUNICATION DEVICE,” (Attorney Docket No. BP3211C1), that was filed on Dec. 20, 2006, pending, that itself claims priority under 35 USC §120 as a continuation of U.S. Pat. No. 7,177,662, entitled, “MULTIMODE WIRELESS COMMUNICATION DEVICE,” (Attorney Docket No. BP3211) that was filed on Apr. 2, 2004, issued on Feb. 13, 2007, the contents of which are all incorporated herein by reference thereto. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field of the Invention 
         [0003]    This invention relates generally to wireless communication systems and more particularly to wireless communication devices that operate in such wireless communication systems. 
         [0004]    2. Description of Related Art 
         [0005]    Communication systems are known to support wireless and wire lined communications between wireless and/or wire lined communication devices. Such communication systems range from national and/or international cellular telephone systems to the Internet to point-to-point in-home wireless networks. Each type of communication system is constructed, and hence operates, in accordance with one or more communication standards. For instance, wireless communication systems may operate in accordance with one or more standards including, but not limited to, IEEE 802.11, Bluetooth, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), and/or variations thereof. 
         [0006]    Depending on the type of wireless communication system, a wireless communication device, such as a cellular telephone, two-way radio, personal digital assistant (PDA), personal computer (PC), laptop computer, home entertainment equipment, et cetera communicates directly or indirectly with other wireless communication devices. For direct communications (also known as point-to-point communications), the participating wireless communication devices tune their receivers and transmitters to the same channel or channels (e.g., one of the plurality of radio frequency (RF) carriers of the wireless communication system) and communicate over that channel(s). For indirect wireless communications, each wireless communication device communicates directly with an associated base station (e.g., for cellular services) and/or an associated access point (e.g., for an in-home or in-building wireless network) via an assigned channel. To complete a communication connection between the wireless communication devices, the associated base stations and/or associated access points communicate with each other directly, via a system controller, via the public switch telephone network, via the Internet, and/or via some other wide area network. 
         [0007]    For each wireless communication device to participate in wireless communications, it includes a built-in transceiver (i.e., receiver and transmitter) or is coupled to an associated transceiver (e.g., a station for in-home and/or in-building wireless communication networks, RF modem, etc.). As is known, the transmitter includes a data modulation stage, one or more intermediate frequency stages, and a power amplifier. The data modulation stage converts raw data into baseband signals in accordance with a particular wireless communication standard. The one or more intermediate frequency stages mix the baseband signals with one or more local oscillations to produce RF signals. The power amplifier amplifies the RF signals prior to transmission via an antenna. 
         [0008]    As is also known, the receiver is coupled to the antenna and includes a low noise amplifier, one or more intermediate frequency stages, a filtering stage, and a data recovery stage. The low noise amplifier receives inbound RF signals via the antenna and amplifies then. The one or more intermediate frequency stages mix the amplified RF signals with one or more local oscillations to convert the amplified RF signal into baseband signals or intermediate frequency (IF) signals. The filtering stage filters the baseband signals or the IF signals to attenuate unwanted out of band signals to produce filtered signals. The data recovery stage recovers raw data from the filtered signals in accordance with the particular wireless communication standard. 
         [0009]    Such a transceiver enables a wireless communication device to function in a particular wireless communication system. For example, if the transceiver is designed to function in an IEEE 802.11a compliant wireless communication system, the transceiver is only operable in such a system and cannot be used in a another wireless communication system (e.g., an IEEE 802.11b or g compliant wireless communication system). With the advent of multiple wireless communication standards (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, etc.) it would be advantageous if a wireless communication device could operation in multiple wireless communication systems with minimal added complexity to the one wireless communication system transceiver structure. 
         [0010]    Therefore a need exists for a multiple mode wireless communication device that is operable in multiple standard compliant wireless communication systems. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    The multimode wireless communication device of the present invention substantially meets these needs and others. In one embodiment, a multimode wireless communication includes a digital baseband processing module, an analog to digital converter module, a digital to analog converter module, a first radio section, and a second radio section. The digital baseband processing module is operably coupled to convert outbound data into outbound digital baseband signals and to convert inbound digital baseband signals into inbound data. The analog to digital converter module is operably coupled to convert inbound analog baseband signals into the inbound digital baseband signals. The digital to analog converter module is operably coupled to convert the outbound digital baseband signals into outbound analog baseband signals. The first radio section is operably coupled to convert the outbound analog baseband signals into first outbound radio frequency (RF) signals and to convert first inbound RF signals into the inbound analog baseband signals when the wireless communication device is in a first mode of operation. The second radio section is operably coupled to convert the outbound analog baseband signals into second outbound RF signals and to convert second inbound RF signals into the inbound analog baseband signals when the wireless communication device is in a second mode of operation. Such a multiple mode wireless communication device is operable in multiple standard compliant wireless communication systems. 
         [0012]    In another embodiment, a multimode wireless communication device includes a first integrated circuit and a second integrated circuit. The first integrated circuit includes a digital baseband processing module, an analog to digital converter module, a digital to analog converter module, and a first radio section. The second integrated circuit includes a second radio section. The digital baseband processing module is operably coupled to convert outbound data into outbound digital baseband signals and to convert inbound digital baseband signals into inbound data. The analog to digital converter module is operably coupled to convert inbound analog baseband signals into the inbound digital baseband signals. The digital to analog converter module is operably coupled to convert the outbound digital baseband signals into outbound analog baseband signals. The first radio section is operably coupled to convert the outbound analog baseband signals into first outbound radio frequency (RF) signals and to convert first inbound RF signals into the inbound analog baseband signals when the wireless communication device is in a first mode of operation. The second radio section is operably coupled to convert the outbound analog baseband signals into second outbound RF signals and to convert second inbound RF signals into the inbound analog baseband signals when the wireless communication device is in a second mode of operation. Such a multiple mode wireless communication device is operable in multiple standard compliant wireless communication systems. 
         [0013]    In yet another embodiment, a multimode wireless communication device includes a first integrated circuit, a second integrated circuit, and a third integrated circuit. The first integrated circuit includes a digital baseband processing module, an analog to digital converter module, and a digital to analog converter module. The second integrated circuit includes a first radio section. The third integrated circuit includes a second radio section. The digital baseband processing module is operably coupled to convert outbound data into outbound digital baseband signals and to convert inbound digital baseband signals into inbound data. The analog to digital converter module is operably coupled to convert inbound analog baseband signals into the inbound digital baseband signals. The digital to analog converter module is operably coupled to convert the outbound digital baseband signals into outbound analog baseband signals. The first radio section is operably coupled to convert the outbound analog baseband signals into first outbound radio frequency (RF) signals and to convert first inbound RF signals into the inbound analog baseband signals when the wireless communication device is in a first mode of operation. The second radio section is operably coupled to convert the outbound analog baseband signals into second outbound RF signals and to convert second inbound RF signals into the inbound analog baseband signals when the wireless communication device is in a second mode of operation. Such a multiple mode wireless communication device is operable in multiple standard compliant wireless communication systems. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0014]      FIG. 1  is a schematic block diagram of a wireless communication device in accordance with the present invention; 
           [0015]      FIG. 2  is a schematic block diagram of a diversity antenna arrangement that may be used by a wireless communication device in accordance with the present invention; 
           [0016]      FIG. 3  is a schematic block diagram of an alternate wireless communication device in accordance with the present invention; 
           [0017]      FIG. 4  is a schematic block diagram of another embodiment of a wireless communication device in accordance with the present invention; and 
           [0018]      FIG. 5  is a schematic block diagram of the 1 st  and/or 2 nd  radio section of a wireless communication device in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]      FIG. 1  is a schematic block diagram of a wireless communication device  10  that includes a digital baseband processing module  12 , an analog-to-digital converter module  14 , a digital-to-analog converter module  16 , a 1 st  radio section  18 , and a 2 nd  radio section  20 . The wireless communication device  10  may be operable in multiple standardized wireless communication systems including, but not limited to, IEEE 802.11a systems, IEEE 802.11b systems, and IEEE 802.11g systems. 
         [0020]    The digital baseband processing module  12  includes a processing module and associated memory. The processing module may be a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on operational instructions. The memory may be a single memory device or a plurality of memory devices. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that when the processing module  32  implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. The memory  34  stores, and the processing module  32  executes, operational instructions corresponding to at least some of the steps and/or functions illustrated in  FIGS. 1-4 . 
         [0021]    The digital baseband processing module  12  is operably coupled to convert outbound data  36 , which may correspond to raw data produced by a host device coupled to the wireless communication device  10  and/or raw data generated by the wireless communication device  10  for transmission, into outbound digital baseband signals  38 . The digital baseband processing module  12  may convert the outbound data  36  into the outbound digital baseband signals  38  by performing one or more of forward error correction coding, interleaving, mapping, performing an inverse fast Fourier transform, adding a guard interval, and/or symbol wave shaping. 
         [0022]    The digital baseband processing module  12  is also operably coupled to convert inbound digital baseband signals  32  into inbound data  34 . Such processing may include performing guard interval removal, fast Fourier transform, demapping, deinterleaving, and/or forward error decoding. Such processing of inbound and outbound data by the digital baseband processing module may be in accordance with one or more of, but not limited to, the IEEE 802.11a standard, IEEE 802.11b standard and/or the IEEE 802.11g standard. 
         [0023]    The digital-to-analog converter module  16  is operably coupled to convert the outbound digital baseband signals  38  into outbound analog baseband signals  40 . The 1 st  radio section  18  and 2 nd  radio section  20  both receive the outbound analog baseband signals  40 . In a 1 st  mode of operation  22  of the wireless communication device, the 1 st  radio section  18  is enabled to convert the outbound analog baseband signals  40  into outbound radio frequency signals  42 . In this mode, the 2 nd  radio section  20  is inactive. In a 2 nd  mode of operation  24  of the wireless communication device, the 2 nd  radio section  20  is enabled and the 1 st  radio section  18  is disabled. In this mode, the 2 nd  radio section  20  converts the outbound analog baseband signals  40  into the outbound RF signals  44 . Note that in one embodiment, the 1 st  radio section  18  may convert the outbound analog baseband signals  40  into the outbound radio frequency signals  42 , wherein the outbound radio frequency signals  42  have a carrier frequency of approximately 2.4 GHz. Further note that the 2 nd  radio section  20  may convert the outbound analog baseband signals  40  into the outbound radio frequency signals  44 , where the outbound radio frequency signal  44  have a carrier frequency of approximately 5.2 to 5.7 GHz. 
         [0024]    When the wireless communication device is in the 1 st  mode of operation  22 , the 1 st  radio section  18  may receive inbound radio frequency signals  26 . In this instance, the 1 st  radio section  18  converts the inbound radio frequency signals  26  into inbound analog baseband signals  30 . The analog-to-digital converter module  14  converts the inbound analog baseband signals  30  into the inbound digital baseband signals  32 . The digital baseband processing module  12  converts the inbound digital baseband signals  32  into the inbound data  34  in accordance with the 1 st  mode of operation  22 , which may correspond to IEEE 802.11a, IEEE 802.11b, or IEEE 802.11g. 
         [0025]    When the wireless communication device is in a 2 nd  mode of operation  24 , the 2 nd  radio section  20  may receive inbound radio frequency signals  28  and convert them into the inbound analog baseband signals  30 . The analog-to-digital converter module  14  converts the inbound analog baseband signals  30  into the inbound digital baseband signals  32 . The digital baseband processing module  12 , in accordance with the 2 nd  mode of operation  24 , converts the inbound digital baseband signals  32  into the inbound data  34 . 
         [0026]      FIG. 2  is a schematic block diagram of a diversity antenna arrangement that may be utilized by the wireless communication device  10  to transceive radio frequency signals. In this embodiment, the diversity antenna arrangement includes two antennas  50  and  52 , two diplexers  54  and  56 , and two transmit/receive switches  58  and  60 . As shown, diplexer  54  is coupled to antenna  50  and diplexer  56  is coupled to antenna  52 . In a diversity application, either antenna  50  is enabled or antenna  52  is enabled via the diversity selection, which also enables the corresponding diplexer  54  or  56 . For instance, if antenna  50  is selected, diplexer  54  is activated while diplexer  56  is deactivated. 
         [0027]    Each transmit/receive switch  58  and  60  is operably coupled to both diplexers  54  and  56 . As is further shown, transmit/receive switch  58  is coupled to the 1 st  radio section  18  while transmit/receive switch  60  is coupled to the 2 nd  radio section  20 . As coupled, either the 1 st  or 2 nd  radio section  18  or  20  may be activated to transceive radio frequency signals via either antenna  50  or  52 . For example, if the 1 st  radio section  18  is activated during the 1 st  mode of operation  22  and antenna  52  has been selected, diplexer  56  is activated and transmit/receive switch  58  provides the coupling between the 1 st  radio section  18  and the diplexer  56 . Alternatively, if the 2 nd  radio section  20  is activated when the wireless communication device is in the 2 nd  mode of operation  24 , and antenna  52  is selected, the transmit/receive switch  60  provides the coupling between diplexer  56  and the 2 nd  radio section  20 . 
         [0028]    As one of average skill in the art will appreciate, the transmit/receive switch  58  and  60  may be implemented on-chip with the corresponding radio sections  18  or  20  or off-chip with respect to the radio sections  18  or  20 . Further, diplexers  54  and  56  may be implemented on-chip with the transmit/receive switch  58  and/or off-chip with respect to the transmit/receive switch  58  or  60 . 
         [0029]      FIG. 3  is a schematic block diagram of a wireless communication device  70  that supports multiple wireless communication standards including, but not limited to, IEEE 802.11a, IEEE 802.11b and IEEE 802.11g. In this embodiment, the digital baseband processing module  12 , the digital-to-analog converter module  16 , the analog-to-digital converter module  14  and the 1 st  radio section  18  are implemented on a single integrated circuit  75 . The 2 nd  radio section  20  is implemented on a 2 nd  integrated circuit  80 . As is further shown, both the 1 st  and 2 nd  radio sections  18  and  20  are operably coupled to an antenna structure  82  which may be implemented as illustrated in  FIG. 2  or may include a single transmit/receive switch coupled to a single antenna. 
         [0030]    As is further shown, the digital-to-analog converter module  16  includes an in-phase (I) digital-to-analog converter  16 -I, and a quadrature (Q) digital-to-analog converter  16 -Q. Similarly, the analog-to-digital converter module  14  includes an in-phase analog-to-digital converter  14 -I and a quadrature analog-to-digital converter  14 -Q. 
         [0031]    The digital baseband processing module  12  includes a control module  76 , an inbound data media specific access control protocol layer (IN-MAC), a coupling module, an inbound physical layer (IN-PHY) for IEEE 802.11b, an inbound physical layer (IN-PHY) for IEEE 802.11a, a 1 st  multiplexer  72 , a 2 nd  multiplexer  74 , an outbound physical layer (OUT-PHY) for IEEE 802.11b, an outbound physical layer (OUT-PHY) for IEEE 802.11a, a decoupling module, and an outbound media specific access control protocol module (OUT-MAC). As configured, the digital baseband processing module  12  may convert the outbound data  36  into the outbound digital baseband signals  38  in accordance with IEEE 802.11a, IEEE 802.11b or IEEE 802.11g under the control of control module  76 . When the digital baseband processing module  12  is to perform in accordance with IEEE 802.11a, the control module  76  enables the outbound MAC layer to convert the outbound data  36  into outbound symbols in accordance with IEEE 802.11a and provide, via path “a”, the symbols to the outbound physical layer for IEEE 802.11a. The outbound physical layer IEEE 802.11a converts the symbols into the outbound digital baseband signals  38 , which via multiplexer  74 , are provided to the in-phase and quadrature digital-to-analog converters  16 -Q and  16 -I. 
         [0032]    When the digital baseband processing module  12  is to operate in accordance with IEEE 802.11b, the control module  76  enables the outbound MAC layer to convert the outbound data  36  into outbound symbols “b”. The outbound physical layer for IEEE 802.11b converts the outbound symbols into the outbound digital baseband signals  38  which, via multiplexer  74  are provided as in-phase and quadrature signals to the digital-to-analog converters  16 -Q and  16 -I. 
         [0033]    When the digital baseband processing module  12  is configured to support IEEE 802.11g, the control module  76  enables the outbound MAC layer to convert the outbound data  36  into symbols “g”. The decoupling module decouples the symbols and provides the decoupled symbols to the outbound physical layer for IEEE 802.11b and to the outbound physical layer for IEEE 802.11a. The outputs of these physical layers are combined to produce the IEEE 802.11g compliant outbound digital baseband signals  38  which, via multiplexer  74 , are provided to the in-phase and quadrature digital-to-analog converters  16 -I and  16 -Q. 
         [0034]    Depending on the mode of operation, the control module  76  enables the 1 st  radio section  18  and disables the 2 nd  radio section  20  such that the 1 st  radio section for IEEE 802.11b or IEEE 802.11g operation is enabled to convert the outbound analog baseband signals  40  into the outbound RF signals  42 . Alternatively, if the mode of operation corresponds to IEEE 802.11a applications, the control module  76 , via the interface to the 2 nd  integrated circuit  80 , enables the 2 nd  radio section  20  and disables the 1 st  radio section  18 . As such, the 2 nd  radio section  20  may convert the outbound analog baseband signals  40  into the outbound radio frequency signals  44 . 
         [0035]    When the wireless communication device is in an IEEE 802.11b mode, RF signals are received via the antenna structure  82  and the 1 st  radio section  18 . The inbound radio frequency signals are converted into inbound analog baseband signals  30  and provided to the in-phase and quadrature analog-to-digital converters  14 -I and  14 -Q. The in-phase and quadrature analog-to-digital converters convert the inbound analog baseband signals  30  into inbound digital baseband signals  32 . 
         [0036]    In this mode, multiplexer  72  is enabled, via control module  76 , to provide the inbound in-phase and quadrature digital signals to the inbound physical layer for IEEE 802.11b applications. The inbound physical layer for IEEE 802.11b converts the inbound digital signals into inbound symbols that are provided to the inbound MAC layer. The inbound MAC layer converts the inbound symbols “b” into the inbound data  34 . 
         [0037]    When the wireless communication device  70  is in IEEE 802.11g operation, the 1 st  radio section  18  is activated and the 2 nd  radio section  20  is deactivated. As such, the 1 st  radio section  18  receives the inbound RF signals and converts them into inbound analog baseband signals. The digital-to-analog converters convert the in-phase and quadrature components of the inbound analog baseband signals into corresponding digital baseband signals. In this mode, multiplexer  72  provides the inbound digital baseband signals to both the inbound physical layers for IEEE 802.11b and IEEE 802.11a. The outputs of the inbound physical layers are provided to a coupling module, which combines the symbols produced by each physical layer into the symbols for IEEE 802.11g. The inbound MAC layer converts the symbols “g” into the inbound data  34 . 
         [0038]    When the wireless communication device  70  is in an IEEE 802.11a mode, the 1 st  radio section  18  is deactivated and the 2 nd  radio section  20  is activated. In this instance, the 2 nd  radio section  20  receives inbound radio frequency signals and converts them into inbound analog baseband signals that are provided to the in-phase and quadrature digital-to-analog converters  16 -I and  16 -Q. The resulting digital in-phase and quadrature baseband signals are provided via multiplexer  72  to the inbound physical layer for IEEE 802.11a. The inbound physical layer produces inbound symbols in accordance to IEEE 802.11a which are provided to the inbound MAC layer. The inbound MAC layer converts the inbound symbols into the inbound data  34 . 
         [0039]      FIG. 4  is a schematic block diagram of another wireless communication device  90  that includes 3 integrated circuits  82 ,  80 , and  84 . In this embodiment, the 1 st  integrated circuit  82  includes the digital baseband processing module  12 , the in-phase and quadrature digital-to-analog converters  16 -I and  16 -Q, and the in-phase and quadrature analog-to-digital converters  14 -I and  14 -Q. The 2 nd  integrated circuit includes the 2 nd  radio section  18  and the 3 rd  integrated circuit  84  includes the 1 st  radio section  18 . In this embodiment, control module  76  of the 1 st  integrated circuit is coupled via a control interface to both integrated circuits  80  and  84 . The control interface may be a 4-wire joint test action group (JTAG) interface. The processing of inbound data in accordance with IEEE 802.11a mode of operation, IEEE 802.11b mode of operation and IEEE 802.11g mode of operation is conceptually the same as described with reference to  FIG. 3 . 
         [0040]    In this embodiment, the control module  76  establishes the particular mode of operation via the control interface with the 2 nd  and 3 rd  integrated circuits  80  and  84 . For instance, when the wireless communication device  90  is in an IEEE 802.11a mode of operation, the control module  76  enables the 2 nd  radio section  20  and disables the 1 st  radio section  18 . In addition, the 802.11b processing core within the digital baseband processing module  12  is disabled (i.e., no clock signals). To disable the 1 st  radio section, the 4-wire interface coupled thereto is inactive, which may be achieved by setting all the signals thereon to zeros. In addition, the 802.11g physical layer mode of operation is placed in an 802.11a mode. Still further, the clock generator of the 1 st  integrated circuit  82  provides clocking signals to the 2 nd  integrated circuit  80 . 
         [0041]    To place the 1 st  radio section  18  in a disabled mode, the transmit power-up input, the receive power-up input, the synthesizer power-up input, the antenna select input and the transmit/receive switch selection inputs are all set to zero. This may be done by writing to the radio frequency overrides of the 1 st  radio section  18  prior to entering the IEEE 802.11a mode of operation. In addition, the crystal power-up input for the 1 st  radio section  18  should be set to zero, which can be controlled through the general purpose input/output registers of the 1 st  radio section  18 . 
         [0042]    When the wireless communication device  90  is to be placed in the IEEE 802.11g mode, the 2 nd  radio section  20  is inactivated and the 1 st  radio section  18  is activated. Further, the 4-wire interface with the 2 nd  radio section  20  should be deactivated and the clock signals produced by the 1 st  integrated circuit should be supplied to the 1 st  radio section  18 . 
         [0043]    To place the 2 nd  radio section  20  in an inactive state, the receive enable, transmit enable, voltage control oscillation enable, crystal enable should all be set to zero, which can be done via the 4-wire interface with integrated circuit  82 . Further, the antenna select and transmit/receive select inputs of the 1 st  radio section  18  should be set to zero, which may be done by writing to the radio frequency overrides prior to entering the 802.11g mode of operation. Still further, the power amplifier of the 1 st  radio section  18  should be disabled, which again can be done by writing to the RF overrides prior to entering the IEEE 802.11g mode of operation. 
         [0044]    The control module  76  also provides functionality to switch from being in one mode of operation to another. For example, when the wireless communication device is in an IEEE 802.11g mode of operation and desires to switch to IEEE 802.11a mode of operation, the control module  76  controls such a transition as follows. To achieve this transition, the control module disables the power-down of the 2 nd  radio section  20 . After doing this, the control module  76  writes to the “g” physical layer override controls to set the 1 st  radio sections transmit power-up, receive power-up and synthesizer power-up to zero thus, beginning to turn-off the 1 st  radio section. The control module  76  then waits for a period of time (e.g., a few microseconds) for the crystal oscillator of the 1 st  radio section  18  to settle. 
         [0045]    The control module then sets the 802.11a physical layer synthesis power-up override to zero for the 1 st  radio section  18 . The control module then sets the receive power-down receive signal strength indication power-down, VCO power-down to zero of the 2 nd  radio section  20  via the 4-wire interface, which begins to enable the 2 nd  radio section  20 . The control module then asserts a physical layer reset and waits for a few microseconds for the reset to propagate through the digital baseband processing module  12 . 
         [0046]    The control module then disables the 802.11g mode of operation within the digital baseband processing module  12  and then waits for a few microseconds for the reset to propagate throughout the digital baseband processing module  12 . The control module then couples the clock signals generated by the 1 st  integrated circuit to the 2 nd  radio section  20  in the 2 nd  integrated circuit and then disables the clock connections with the 3 rd  integrated circuit, which supports the 1 st  radio section  18 . After wait periods for the phase locked loop of the 1 st  integrated circuit to settle and the frequency synthesizer of the 2 nd  integrated circuit to settle, the control module  76  removes the reset condition of the digital baseband processing module  12  and then places it in the IEEE 802.11a mode of operation. The digital baseband processing module  12  then writes to the “a” physical layer analog override controls to disable analog overrides thereby enabling the IEEE 802.11a mode of operation. 
         [0047]    The control module may also coordinate the switching from IEEE 802.11a mode of operation to IEEE 802.11a mode of operation to IEEE 802.11g mode of operation. In this mode transformation, the control module  76  begins by enabling the crystal oscillator of the 1 st  radio section  18  on the 3 rd  integrated circuit  84 . The control module then powers down the transmit, receive and VCO (voltage controlled oscillator) of the 2 nd  radio section  20  via the 4-wire interface and waits for the crystal oscillator of the 3 rd  integrated circuit to settle. The control module then writes to the “g” physical layer override registers to remove overrides on the synthesizer power-up, which may be done by utilizing the “b” physical layer override controls and/or dedicated “g” override controls. 
         [0048]    The control module then enables the “g” mode of operation within a digital baseband processing module  12  and adjusts the phase locked loop of the 1 st  integrated circuit  82 . After a wait period, the clock of the 1 st  integrated circuit is coupled to the clock of the 3 rd  integrated circuit and a wait period is begun for the clocks to synchronize. 
         [0049]    The control module then writes to the “g” physical layer override registers to remove overrides on the transmit power-up and receive power-up for the “g” mode of operation. The control module then disables the 2 nd  radio section  20  and writes to the “g” physical analog override controls to disable analog overrides for the “g” mode of operation which now may be commenced. 
         [0050]    The control module further controls switching into the 802.11g mode of operation after a power-on reset. This may be done by turning on the crystal oscillator within the 3 rd  integrated circuit and waiting a period of time (e.g., microseconds) for the oscillator to settle. Next, the control module asserts the physical reset and sets the “g” mode of operation to 1. The control module then selects the 3 rd  integrated circuit  84  output clock for the 1 st  integrated circuit clock generation phase locked loop and waits for the phase locked loop to settle. The control module then takes the physical layer out of reset and waits for a few clock cycles. The control module then sets the force gated clocks on to zero, which disables the clock signals to the 2 nd  radio section  20 . The control module then writes to the “g” physical layer override registers to remove overrides on the transmit power-up, receive power-up and synthesizer power-up for the 3 rd  integrated circuit. The control module then initializes the digital baseband processing module  12  for the “g” mode of operation. The control module then sets the crystal oscillator power-down for the 2 nd  radio section  20  to zero via the 4-wire interface. The control module then writes to the “g” physical layer analog override controls to disable the analog overrides thus enabling the wireless communication device  20  to operate in the IEEE 802.11g mode. 
         [0051]    The control module further functions to switch into the IEEE 802.11a mode after a power-on reset condition. In this mode, the control module asserts physical reset, sets the “g” mode of operation to zero and sets the force gated clocks on to 1 and waits for Q clock cycles thus beginning the clocking circuitry within the 2 nd  radio section  20 . The control module  76  then selects the 2 nd  integrated circuit output clocks for the 1 st  integrated circuit clock generator phase locked loop. The control module then disables the crystal oscillator of the 1 st  radio section  18 . After a wait period for the phase locked loop of the 1 st  integrated circuit to settle, the control module takes the physical layer out of reset within the 1 st  integrated circuit. The control module then sets the force gated clocks on to zero for the 1 st  radio section  18 . The control module then writes to the “g” physical layer override controls to disable the transmit power-up, receive power-up and synthesizer power-up for the 3 rd  integrated circuit. The control module then enables the synthesizer power-up for the “a” mode of operation and subsequently enables the receive power-up, transmit power-up, RSSI power-up and VCO power-up via the 4-wire interface for the 2 nd  radio section  20 . The control module then enables the digital baseband processing module  12  for IEEE 802.11a mode of operation and then writes to the “a” physical layer analog override controls to disable analog overrides such that the wireless communication device  90  is enabled for IEEE 802.11a operations. 
         [0052]      FIG. 5  is a schematic block diagram of the 1 st  or 2 nd  radio sections  18  or  20 . As shown, each radio section  18  or  20  includes a receiver section and a transmitter section. The receiver section includes a receiver filter module  100  that receives RF signals from the antenna or from a corresponding transmit/receive switch. The receive filter module  100  bandpass filters that passes RF signals of interest to the low noise amplifier  102 . The low noise amplifier  102  amplifies the signals and provides it to the down-conversion module  104 . Based on a receiver local oscillation (RX LO) the down conversion module  104  converts the inbound radio frequency signals to a baseband signal which is subsequently filtered and/or gain adjusted via the filtering/gain module  106 . The output of filter/gain module  106  is provided to the analog-to-digital converter. 
         [0053]    The transmitter section includes the filter/gain module  110  that receives analog signals from the digital-to-analog converter and provides them to the up-conversion module  112 . The up-conversion module  112 , based on a transmit local oscillation (TX LO) converts the baseband analog signals into radio frequency signals that are amplified via power amplifier  114 . The transmit filter module  116  bandpass filters the radio frequency signals from the power amplifier  114  and provides them either to an antenna or to a corresponding transmit switch. 
         [0054]    The local oscillation module  108  produces the receive local oscillation and the transmit local oscillation based on internally generated clock signals or clock signals received from another integrated circuit. 
         [0055]    As one of average skill in the art will appreciate, the term “substantially” or “approximately”, as may be used herein, provides an industry-accepted tolerance to its corresponding term. Such an industry-accepted tolerance ranges from less than one percent to twenty percent and corresponds to, but is not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, and/or thermal noise. As one of average skill in the art will further appreciate, the term “operably coupled”, as may be used herein, includes direct coupling and indirect coupling via another component, element, circuit, or module where, for indirect coupling, the intervening component, element, circuit, or module does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As one of average skill in the art will also appreciate, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two elements in the same manner as “operably coupled”. As one of average skill in the art will further appreciate, the term “compares favorably”, as may be used herein, indicates that a comparison between two or more elements, items, signals, etc., provides a desired relationship. For example, when the desired relationship is that signal  1  has a greater magnitude than signal  2 , a favorable comparison may be achieved when the magnitude of signal  1  is greater than that of signal  2  or when the magnitude of signal  2  is less than that of signal  1 . 
         [0056]    The preceding discussion has presented a multimode wireless communication device that is operable in multiple wireless communication systems with minimal additional circuitry. As one of average skill in the art will appreciate, other embodiments may be derived from the teaching of the present invention without deviating from the scope of the claims.