Abstract:
Apparatus having corresponding methods and computer-readable media comprise: a first transceiver comprising a controller configured to select one of a plurality of frequency regions, wherein bandwidths of the frequency regions are non-uniform, and wherein the first transceiver is configured to transceive, according to a first protocol, first wireless signals in the one of the plurality of frequency regions selected by the controller; an arbiter configured to select one or more frequency channels based on the one of the plurality of the frequency regions selected by the controller; and a second transceiver configured to transceive, according to a second protocol, second wireless signals only in the one or more frequency channels selected by the arbiter.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This disclosure claims the benefit of U.S. Provisional Patent Application Ser. No. 61/534,657, filed on Sep. 14, 2011, entitled “Non-uniform Frequency Operation Region for In-device Co-existence Interference Avoidance,” the disclosure thereof incorporated by reference herein in its entirety. 
     
    
     FIELD 
       [0002]    The present disclosure relates generally to the field of wireless communication. More particularly, the present disclosure relates to avoiding interference between different wireless communication technologies that use adjacent or overlapping frequency bands. 
       BACKGROUND 
       [0003]    The popularity of multiple wireless communication technologies for handheld platforms has created a need to integrate multiple wireless communication technologies on a single wireless communication device. However, the frequency bands of some of these technologies are close enough to result in interference. For example, the un-licensed 2.4 GHz Industrial, Scientific and Medical (ISM) frequency band is adjacent to some of the bands used by Mobile Wireless Standards (MWS) technologies to result in adjacent channel interference. In many electronic devices such as smartphones, both ISM and MWS technologies are implemented in the same device. For example, a smartphone may employ LTE (Long Term Evolution) for phone calls, WiFi for local area networking, and Bluetooth for headsets. LTE transmissions from the smartphone will cause adjacent channel interference with incoming Bluetooth and WiFi signals. Similarly, Bluetooth and WiFi transmissions from the smartphone will cause adjacent channel interference with incoming LTE signals. This adjacent channel interference can significantly degrade performance not only at the smartphone, but also at connected MWS base stations. 
       SUMMARY 
       [0004]    In general, in one aspect, an embodiment features an apparatus comprising: a first transceiver comprising a controller configured to select one of a plurality of frequency regions, wherein bandwidths of the frequency regions are non-uniform, and wherein the first transceiver is configured to transceive, according to a first protocol, first wireless signals in the one of the plurality of frequency regions selected by the controller; an arbiter configured to select one or more frequency channels based on the one of the plurality of the frequency regions selected by the controller; and a second transceiver configured to transceive, according to a second protocol, second wireless signals only in the one or more frequency channels selected by the arbiter. 
         [0005]    Embodiments of the apparatus can include one or more of the following features. In some embodiments, the first protocol is a Mobile Wireless Standards (MWS) protocol; and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, the first protocol is an Industrial, Scientific and Medical (ISM) band protocol; and the second protocol is a Mobile Wireless Standards (MWS) protocol. In some embodiments, each of the first protocol and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, one of the frequency regions includes a plurality of frequency sub-regions; the controller is further configured to select one of the plurality of the frequency sub-regions; the first transceiver is further configured to transceive the first wireless signals in the one of the plurality of the frequency sub-regions selected by the controller; and the arbiter is further configured to select the one or more frequency channels based on the one of the plurality of the frequency sub-regions selected by the controller. In some embodiments, the controller is further configured to provide an information signal, wherein the information signal indicates the one of the plurality of the frequency regions selected by the controller; and the arbiter is further configured to select the one or more frequency channels based on the information signal provided by the controller. Some embodiments comprise one or more integrated circuits comprising the apparatus. Some embodiments comprise an electronic communication device comprising the apparatus. 
         [0006]    In general, in one aspect, an embodiment features a method comprising: 
         [0007]    selecting one of a plurality of frequency regions, wherein bandwidths of the frequency regions are non-uniform; transceiving, according to a first protocol, first wireless signals in the one of the plurality of the frequency regions; selecting one or more frequency channels based on the selected one of the plurality of the frequency regions; and transceiving, according to a second protocol, second wireless signals only in the one or more frequency channels. 
         [0008]    Embodiments of the method can include one or more of the following features. In some embodiments, the first protocol is a Mobile Wireless Standards (MWS) protocol; and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, the first protocol is an Industrial, Scientific and Medical (ISM) band protocol; and the second protocol is a Mobile Wireless Standards (MWS) protocol. In some embodiments, each of the first protocol and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. Some embodiments comprise selecting one of a plurality of frequency sub-regions, wherein one of the frequency regions includes the plurality of the frequency sub-regions; transceiving the first wireless signals in the one of the plurality of the frequency sub-regions; and selecting the one or more frequency channels based on the one of the plurality of the frequency sub-regions. Some embodiments comprise providing an information signal, wherein the information signal indicates the one of the plurality of the frequency regions; and selecting the one or more frequency channels based on the information signal. 
         [0009]    In general, in one aspect, an embodiment features computer-readable media embodying instructions executable by a computer in an electronic device to perform functions comprising: selecting one of a plurality of frequency regions, wherein bandwidths of the frequency regions are non-uniform; causing the electronic device to transceive, according to a first protocol, first wireless signals in the one of the plurality of the frequency regions; selecting one or more frequency channels based on the one of the plurality of the frequency regions; and causing the electronic device to transceive, according to a second protocol, second wireless signals only in the one or more frequency channels. 
         [0010]    Embodiments of the computer-readable media can include one or more of the following features. In some embodiments, the first protocol is a Mobile Wireless Standards (MWS) protocol; and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, the first protocol is an Industrial, Scientific and Medical (ISM) band protocol; and the second protocol is a Mobile Wireless Standards (MWS) protocol. In some embodiments, each of the first protocol and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, the functions further comprise: selecting one of a plurality of frequency sub-regions, wherein one of the frequency regions includes the plurality of the frequency sub-regions; transceiving the first wireless signals in the one of the plurality of the frequency sub-regions; and selecting the one or more frequency channels based on the one of the plurality of the frequency sub-regions. In some embodiments, the functions further comprise: providing an information signal, wherein the information signal indicates the selected one of the plurality of the frequency regions; and selecting the one or more frequency channels based on the information signal. 
         [0011]    The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1  shows elements of a communication system according to one embodiment. 
           [0013]      FIG. 2  illustrates graphically how different channels in one transceiver generate different levels of interference for different channels in the other transceiver. 
           [0014]      FIG. 3  shows an example mapping of LTE channels 1-5 into frequency regions and sub-regions having non-uniform bandwidths. 
           [0015]      FIG. 4  shows a process for the user equipment of  FIG. 1  according to an embodiment where the arbiter assigns WiFi channels to the WiFi MAC based on the LTE channels used by the LTE device. 
           [0016]      FIG. 5  shows a process for the user equipment of  FIG. 1  according to an embodiment where the arbiter assigns LTE channels to the LTE device based on the WiFi channels used by the WiFi MAC. 
       
    
    
       [0017]    The leading digit(s) of each reference numeral used in this specification indicates the number of the drawing in which the reference numeral first appears. 
       DETAILED DESCRIPTION 
       [0018]    Embodiments of the present disclosure provide coexistence among multiple wireless communication technologies based on the frequency regions used by one or more of the wireless signals, where bandwidths of the frequency regions are non-uniform. In some cases, the wireless communication technologies use adjacent frequency bands, and so cause adjacent channel interference. For example, some bands used by Mobile Wireless Standards (MWS) technologies are adjacent to the Industrial, Scientific and Medical (ISM) frequency band. In other cases, the interference results from wireless communication technologies using frequency bands that partially or fully overlap. For example, both WiFi and Bluetooth use the ISM frequency band. 
         [0019]      FIG. 1  shows elements of a communication system  100  according to one embodiment. Although in the described embodiments the elements of the communication system  100  are presented in one arrangement, other embodiments may feature other arrangements. For example, elements of the communication system  100  can be implemented in hardware, software, or combinations thereof. 
         [0020]    Referring to  FIG. 1 , the communication system  100  includes a user equipment (UE)  102  capable of communications using multiple wireless technologies. The user equipment  102  can be implemented as any sort of electronic device capable of performing the functions described herein. For example, the user equipment  102  can be implemented as a smartphone, tablet computer, or the like. Elements of user equipment  102  can be implemented as one or more integrated circuits. 
         [0021]    The user equipment  102  includes multiple transceivers employing different wireless technologies. In the example of  FIG. 1 , the transceivers include a Mobile Wireless Standards (MWS) transceiver and an Industrial, Scientific and Medical (ISM) band transceiver. In other embodiments, other numbers of transceivers and other combinations of wireless technologies can be employed instead. For example, the MWS transceivers can include Long Term Evolution (LTE) transceivers, Worldwide Interoperability for Microwave Access (WiMAX) transceivers, and the like, and the ISM band transceivers can include WiFi transceivers, Bluetooth transceivers, ZigBee transceivers, and the like. The transceivers can include two MWS transceivers or two ISM transceivers. The ISM band equipment can also include receive-only devices such as global positioning system (GPS) receivers, frequency modulation (FM) radio receivers, and the like. 
         [0022]    In the example of  FIG. 1 , the transceivers include a WiFi media access controller (MAC)  104  and an LTE device  108 . Each transceiver communicates using one or more respective antennas. In particular, the WiFi MAC  104  uses one or more antennas  110 , and the LTE device  108  uses one or more antennas  114 . In some embodiments, one or more of the antennas  110 ,  114  can be combined. 
         [0023]    The WiFi MAC  104  includes a receiver (WiFi Rx)  116 , a transmitter (WiFi Tx)  118 , and a WiFi controller  106 . The LTE device  108  includes a receiver (LTE Rx)  120 , a transmitter (LTE Tx)  122 , and an LTE controller  112 . The WiFi MAC  104  uses antenna  110  to transmit and receive wireless WiFi protocol signals  124  (also referred to herein as WiFi signals  124 ). The LTE device  108  uses antenna  114  to transmit and receive wireless LTE protocol signals  126  (also referred to herein as LIE signals  126 ). 
         [0024]    The user equipment  102  also includes an arbiter  128 . The arbiter  128 , the LTE controller  112 , and the WiFi controller  106  can be implemented as one or more processors. Processors according to various embodiments can be fabricated as one or more integrated circuits. The arbiter  128  includes a channel map  138 . The channel map  138  can be stored in an internal memory of the arbiter  128 , in a memory external to the arbiter  128 , or the like. The arbiter  128  receives information signals  130 ,  132  from the transceivers  104 ,  108 , and provides control signals  134 ,  136  to the transceivers  104 ,  108 . The arbiter  128  receives the information signals  130  from the WiFi MAC  104 , and provides the control signals  134  to the WiFi MAC  104 . The arbiter  128  receives the information signals  132  from the LTE device  108 , and provides the control signals  136  to the LIE device  108 . In some embodiments, not all of the information signals  130 ,  132  and control signals  134 ,  136  are used. 
         [0025]    The information signals  130 ,  132  include indications of the frequency regions used by the wireless signals  124 ,  126 , respectively. The indications of the frequency regions used by the wireless signals  124 ,  126  can include indications of the frequency regions used by the wireless signals  124 ,  126  received by the receivers  116 ,  120 , indications of the frequency regions used by the wireless signals  124 ,  126  employed by the transmitters  118 ,  122  to transmit the wireless signals  124 ,  126 , and the like. The frequency regions can include present frequency regions, as well as planned future frequency regions. 
         [0026]    In conventional approaches, the bandwidths of the indicated frequency regions are uniform. For example, the frequency range indication is uniformly distributed for all of the LTE channels. However, such conventional approaches fail to account for the fact that different channels in one transceiver generate different levels of interference for different channels in the other transceiver in the user equipment  102 .  FIG. 2  illustrates this fact graphically for LTE  20  MHz channels 1-5 and WiFi channels 1-5. Referring to  FIG. 2 , each LTE channel has a bandwidth of 20 MHz, and the LTE channel number increases with decreasing frequency. Each WiFi channel has a bandwidth of 22 MHz, and the WiFi channel number increases with increasing frequency. In terms of frequency, the closer an LTE channel is to a WiFi channel, the more interference a WiFi transmission will produce in that LTE channel. For example, in terms of frequency, WiFi channel 1 is much closer to LTE channel than to LTE channel 5. Therefore a WiFi transmission in channel 1 will produce more interference in LTE channel 1 than in LTE channel 5. The spectrum for LTE channel 1 is shown at  200 , where the out-of-band emissions for LTE channel 1 are seen extending into WiFi channels 1 and 2. 
         [0027]    The described embodiments account for this fact by mapping the channels into frequency regions having non-uniform bandwidths.  FIG. 3  shows an example mapping of LIE channels 1-5 into frequency regions having non-uniform bandwidths. Referring to  FIG. 3 , LTE channel 1 is mapped to LIE frequency region 0, while LTE channels 2-5 are mapped to LTE frequency region 1. In this mapping, the frequency regions have non-uniform bandwidths, with LTE frequency region 0 having a bandwidth of 20 MHz and LTE frequency region 1 having a bandwidth of 80 MHz. 
         [0028]    In one embodiment, information signals  132  inform the arbiter  128  of the LTE frequency region employed by LTE device  108 . Based on that LTE frequency region, the arbiter  128  selects one or more WiFi frequency channels available for use by the WiFi MAC  104 , and informs the WiFi MAC  104  of the one or more available frequency channels using control signals  134 . For example, the arbiter  128  employs the channel map  138  to select the one or more available WiFi frequency channels based on the LTE frequency region employed by the LTE device  108 . An example mapping is shown in Table 1. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 LTE frequency region 
                 available WiFi frequency channels 
               
               
                   
                   
               
             
             
               
                   
                 0 
                 5-11 
               
               
                   
                 1 
                 2-11 
               
               
                   
                   
               
             
          
         
       
     
         [0029]    In some embodiments, the LTE frequency regions are divided into LTE frequency sub-regions having non-uniform bandwidths.  FIG. 3  shows an example mapping of LTE channels 1-5 into LTE frequency sub-regions having non-uniform bandwidths. Referring to  FIG. 3 , LTE channel 1 is mapped to LTE frequency regions 00 and 01, LTE channels 2-3 are mapped to LTE frequency sub-region 10, and LTE channels 4-5 are mapped to LTE frequency sub-region 11. In this mapping, the frequency sub-regions have non-uniform bandwidths, with LTE frequency sub-regions 00 and 01 each having a bandwidth of 10 MHz and LTE frequency sub-regions 10 and 11 each having a bandwidth of 40 MHz. 
         [0030]    In one embodiment, information signals  132  inform the arbiter  128  of the LTE frequency sub-region employed by LTE device  108 . Based on that LTE frequency sub-region, the arbiter  128  selects one or more WiFi frequency channels available for use by the WiFi MAC  104 , and informs the WiFi MAC  104  of the one or more available frequency channels using control signals  134 . For example, the arbiter  128  employs the channel map  138  to select the one or more available WiFi frequency channels based on the LTE frequency sub-region employed by the LTE device  108 . An example mapping is shown in Table 2. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 LTE frequency sub-region 
                 available WiFi frequency channels 
               
               
                   
                   
               
             
             
               
                   
                 00 
                 5-11 
               
               
                   
                 01 
                 3-11 
               
               
                   
                 10 
                 2-11 
               
               
                   
                 11 
                 1-11 
               
               
                   
                   
               
             
          
         
       
     
         [0031]    Similar mappings can be used for other sorts of transceivers. For example, in some embodiments, user equipment  102  includes a Bluetooth transceiver, and the arbiter  128  employs the channel map  138  to select the available Bluetooth frequency channels based on the LTE frequency sub-region employed by the LTE device  108 . An example mapping is shown in Table 3. 
         [0000]    
       
         
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 LTE frequency sub-region 
                 available Bluetooth frequency channels 
               
               
                   
               
             
             
               
                 00 
                 21-79 
               
               
                 01 
                 11-79 
               
               
                 10 
                  6-79 
               
               
                 11 
                  1-79 
               
               
                   
               
             
          
         
       
     
         [0032]    In some embodiments, the arbiter  128  uses the channel map  138  to assign channels to the Will MAC  104 , as described above. In other embodiments, the arbiter  128  can assign channels to the WiFi MAC  104  in other ways, for example by using programmable thresholds or frequency offsets to give sufficient frequency gaps between the LTE and WiFi operating regions. It should be noted that the mappings, regions, and subregions of  FIG. 3  and Tables 1-3 are shown by way of example. Other embodiments can feature other mappings, regions, and subregions. 
         [0033]      FIG. 4  shows a process  400  for user equipment  102  of  FIG. 1  according to an embodiment where the arbiter  128  assigns WiFi channels to the WiFi MAC  104  based on the LITE channels used by the LTE device  108 . Although in the described embodiments the elements of process  400  are presented in one arrangement. other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of process  400  can be executed in a different order, concurrently, and the like. Also some elements of process  400  may not be performed, and may not be executed immediately after each other. In addition, some or all of the elements of process  400  can be performed automatically, that is, without human intervention. 
         [0034]    Referring to  FIG. 4 , at  402 , the LTE controller  112  selects one of a plurality of LTE frequency regions or sub-regions, where bandwidths of the frequency regions or sub-regions are non-uniform. The LTE frequency region or sub-region can be assigned to the LTE device  108 , for example, by a base station, also referred to as an LTE evolved Node B (eNB or eNodeB). Subsequently, at  404 , the LTE device  108  transceives, according to the LTE protocol, wireless signals  126  in the selected frequency region or sub-region. 
         [0035]    At  406 , the LTE controller  112  informs the arbiter  128  of the selected LTE frequency region or sub-region. In particular, the LTE controller  112  provides the information signal  132 , where the information signal  132  indicates the selected LTE frequency region or sub-region. For example, the information signal  132  can include the LTE frequency region or sub-region bits listed in Tables 1 and 2 above. At  408 , in response to the information signal  132 , the arbiter  128  selects available WiFi frequency channels based on the information signal  132 , for example as described above. At  410 , the arbiter  128  informs the WiFi MAC  104  of the selected WiFi frequency channels. In particular, the arbiter  128  provides the control signal  134 , where the control signal  134  indicates the selected WiFi frequency channels. At  412 , the WiFi MAC  104  then transceives the WiFi signals  124  on one or more of the selected WiFi frequency channels. 
         [0036]    The techniques described herein can also be used by the arbiter  128  to select available LTE channels based on the WiFi channel in use by the WiFi MAC  104 .  FIG. 5  shows a process  500  for user equipment  102  of  FIG. 1  according to an embodiment where the arbiter  128  assigns LTE channels to the LTE device  108  based on the WiFi channels used by the WiFi MAC  104 . Although in the described embodiments the elements of process  500  are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of process  500  can be executed in a different order, concurrently, and the like. Also some elements of process  500  may not be performed, and may not be executed immediately after each other. In addition, some or all of the elements of process  500  can be performed automatically, that is, without human intervention. 
         [0037]    Referring to  FIG. 5 , at  502 , the WiFi controller  106  selects one of a plurality of WiFi frequency regions or sub-regions, where bandwidths of the frequency regions or sub-regions are non-uniform. The WiFi frequency regions or sub-regions can be mapped to WiFi channels in a manner similar to that shown for the LTE channels in  FIG. 3 . Subsequently, at  504 , the WiFi MAC  104  transceives, according to the WiFi protocol, wireless signals  124  in the selected frequency region or sub-region. 
         [0038]    At  506 , the WiFi controller  106  informs the arbiter  128  of the selected WiFi frequency region or sub-region. In particular, the WiFi controller  106  provides the information signal  130 , where the information signal  130  indicates the selected WiFi frequency region or sub-region. At  508 , in response to the information signal  130 , the arbiter  128  selects available LIE frequency channels based on the information signal  130 , for example in a manner similar to that described above for the selection of available WiFi channels. At  510 , the arbiter  128  informs the LTE device  108  of the selected LTE frequency channels. In particular, the arbiter  128  provides the control signal  136 , where the control signal  136  indicates the selected LTE frequency channels. At  512 , the LTE device  108  then transceives the LTE signals  126  on one or more of the selected LTE frequency channels. 
         [0039]    Various embodiments feature one or more of the following advantages. From the viewpoint of an LIE base station, the downlink resource is saved from engaging in unsuccessful transactions resulting from potentially high interference with WiFi transmissions from the user equipment  102 . Thus the downlink resource can be used for other user equipment  102  resulting in better resource utilization efficiency for the base station. From the viewpoint of WiFi devices in user equipment  102 , the WiFi receive resource is saved from unsuccessful receive transactions resulting from potentially high interference with LTE uplink packets. Note these advantages are achieved without changing existing 3GPP LTE standards. 
         [0040]    Various embodiments of the present disclosure can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations thereof. Embodiments of the present disclosure can be implemented in a computer program product tangibly embodied in a computer-readable storage device for execution by a programmable processor. The described processes can be performed by a programmable processor executing a program of instructions to perform functions by operating on input data and generating output. Embodiments of the present disclosure can be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, processors receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer includes one or more mass storage devices for storing data files. Such devices include magnetic disks, such as internal hard disks and removable disks, magneto-optical disks; optical disks, and solid-state disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits). 
         [0041]    A number of implementations have been described. Nevertheless, various modifications may be made without departing from the scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.