Abstract:
A method for generating an orthogonal frequency division multiplexing (OFDM) frame for wireless communications begins by generating a preamble of the OFDM frame, wherein the preamble includes training information and signal information. The method continues by generating a plurality of data fields of the OFDM frame, wherein each of the plurality of data fields includes a plurality of subcarriers, wherein at least some of the plurality of data fields includes, at most, three of the plurality of subcarriers allocated for a pilot signal.

Description:
[0001]     This patent application is claiming priority to provisional patent application entitled OFDM PHYSICAL LAYER HAVING REDUCED CHANNEL WIDTH, having a provisional Ser. No. of 60/488,531, and a provisional filing date of Jul. 18, 2003, and is claiming priority to co-pending patent application entitled CONFIGURABLE SPECTRAL MASK FOR USE IN A HIGH DATA THROUGHPUT WIRELESS COMMUNICATION, having a Ser. No. of 10/778,754, and a filing date of Feb. 13, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Technical Field of the Invention  
         [0003]     This invention relates generally to wireless communication systems and more particularly to various formats of wireless communications between wireless communication devices affiliated with such wireless communication systems.  
         [0004]     2. Description of Related Art  
         [0005]     Communication technologies that link electronic devices in a networked fashion are well known. Examples of communication networks include wired packet data networks, wireless packet data networks, wired telephone networks, wireless telephone networks, and satellite communication networks. These communication networks typically include a network infrastructure that services a plurality of client devices. The Public Switched Telephone Network (PSTN) is probably the best-known communication network and has been in existence for many years. The Internet is another well-known example of a communication network that has also been in existence for a number of years. These communication networks enable client devices to communicate with each other on a global basis. Wired Local Area Networks (LANs), e.g., Ethernets, are also quite common and support communications between networked computers and other devices within a serviced area. LANs also often link serviced devices to Wide Area Networks and the Internet. Each of these networks is generally considered a “wired” network, even though some of these networks, e.g., the PSTN, may include some transmission paths that are serviced by wireless links.  
         [0006]     Wireless networks have been in existence for a relatively shorter period in comparison to wired networks and include, for example, cellular telephone networks, wireless LANs (WLANs), and satellite communication networks. WLANs are generally established in accordance with one or more standards, such IEEE 802.11, .11(a), .11(b), .11(g), etc, which may be jointly referred to as “IEEE 802.11 networks.” In a typical IEEE 802.11 network, a plurality of wireless Access Points (APs) are wired together and each supports wireless communications with wireless communication devices (e.g., computers that include compatible wireless interfaces). The APs provide the wireless communication devices with access to networks outside the WLAN.  
         [0007]     WLANs provide significant advantages when servicing portable devices such as portable computers, portable data terminals, and other devices that are not typically stationary and able to access a wired LAN connection. However, WLANs provide relatively low data rate service as compared to wired LANs, e.g., IEEE 802.3 networks. Currently deployed wired networks provide up to one Gigabit/second bandwidth and relatively soon, wired networks will provide up to 10 Gigabit/second bandwidths. However, because of their advantages in servicing portable devices, WLANs are often deployed so that they support wireless communications in a service area that overlays with the service area of a wired network. In such installations, devices that are primarily stationary, e.g., desktop computers, couple to the wired LAN while devices that are primarily mobile, e.g., laptop computers, couple to the WLAN. The laptop computer, however, may also have a wired LAN connection that it uses when docked to obtain relatively higher bandwidth service.  
         [0008]     Newer wireless networking standards support relatively greater data rates. For example, the IEEE 802.11 (a) standard supports data rates up to 54 Mega Bits Per Second (MBPS) as does the IEEE 802.11 (g) standard. The IEEE 802.11 (a) uses an Orthogonal Frequency Division Multiplexing (OFDM) physical layer to support this data rate. With the OFDM physical layer, the available spectrum is subdivided into a number of sub-carriers (tones), each of which carries a portion of a demultiplexed data stream. The IEEE 802.11(a) OFDM physical layer includes 48 data carrying tones and 4 pilot tones, with a spacing/width of 0.3125 MHz. As shown in  FIG. 1 , subcarrier  0  (which corresponds to DC), subcarriers  27  through  32 , and subcarriers − 27  through − 31  are not used. Subcarriers ± 7  and ± 21  are used for the four pilot tones, or signals. Subcarriers  1  through  6 , subcarriers  8  through  20 , subcarriers  22  through  26 , subcarriers − 1  through − 6 , subcarriers − 8  through − 20 , and subcarriers − 22  through − 26  make up the 48 subcarriers that carry data.  
         [0009]     While the subcarrier allocation of  FIG. 1  is standardized and supports a wide variety of WLAN applications, there are some WLAN applications where such a subcarrier allocation is limiting. For instance, if the channel bandwidth is narrowed or for multiple input multiple output (MIMO) wireless communications, the subcarrier allocation of  FIG. 1  may not be optimal and/or achievable.  
         [0010]     Therefore, a need exists for a method and apparatus of generating an OFDM frame for narrow channel applications and/or MIMO applications.  
       BRIEF SUMMARY OF THE INVENTION  
       [0011]     The OFDM frame formatting of the present invention substantially meets these needs and others. In one embodiment, a method for generating an orthogonal frequency division multiplexing (OFDM) frame for wireless communications begins by generating a preamble of the OFDM frame, wherein the preamble includes training information and signal information. The method continues by generating a plurality of data fields of the OFDM frame, wherein each of the plurality of data fields includes a plurality of subcarriers, wherein at least some of the plurality of data fields includes, at most, three of the plurality of subcarriers allocated for a pilot signal.  
         [0012]     In another embodiment, a method for generating an orthogonal frequency division multiplexing (OFDM) frame for multiple input multiple output (MIMO) wireless communications begins by converting a stream of data into a plurality of data streams. The method continues by converting the plurality of data streams into a plurality of OFDM frames, wherein each of the plurality of OFDM frames includes a preamble that includes training information and signal information, wherein each of the plurality of OFDM frames includes a plurality of data fields, wherein each of the plurality of data fields of each of the plurality of OFDM frames includes a plurality of subcarriers, wherein at least some of the plurality of data fields of at least one of the plurality of OFDM frames includes, at most, three of the plurality of subcarriers allocated for a pilot signal.  
         [0013]     In yet another embodiment, a method for receiving an orthogonal frequency division multiplexing (OFDM) frame for wireless communications begins by receiving a preamble of the OFDM frame, wherein the preamble includes training information and signal information. The method continues by receiving a plurality of data fields of the OFDM frame, wherein each of the plurality of data fields includes a plurality of subcarriers, wherein, as indicated by the signals information, at least some of the plurality of data fields includes, at most, three of the plurality of subcarriers allocated for a pilot signal. The method continues by converting the plurality of data fields into inbound data.  
         [0014]     In a further embodiment, a method for receiving an orthogonal frequency division multiplexing (OFDM) frame for wireless communications begins by receiving a preamble of the OFDM frame, wherein the preamble includes training information and signal information. The method continues by receiving a plurality of data fields of the OFDM frame, wherein each of the plurality of data fields includes a plurality of subcarriers, wherein, as indicated by the signals information, at least some of the plurality of data fields includes, at most, three of the plurality of subcarriers allocated for a pilot signal. The method continues by converting the plurality of data fields into inbound data.  
         [0015]     In still further embodiments, one of more of such methods may be incorporated in a radio frequency transmitter and/or in a radio frequency receiver.  
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0016]      FIG. 1  is a diagram of a prior art OFDM frame sub-carrier allocation;  
         [0017]      FIG. 2  is a schematic block diagram of a wireless communication system in accordance with the present invention;  
         [0018]      FIG. 3  is a schematic block diagram of a wireless communication device in accordance with the present invention;  
         [0019]      FIG. 4  is a diagram of a wireless communication in accordance with the present invention;  
         [0020]      FIG. 5  is a diagram illustrating OFDM frame sub-carrier allocation in accordance with the present invention;  
         [0021]      FIG. 6  is an alternate diagram of OFDM frame sub-carrier allocations in accordance with the present invention;  
         [0022]      FIG. 7  is a table corresponding to 802.11a and narrower channel applications in accordance with the present invention;  
         [0023]      FIG. 8  is a diagram of an OFDM baseband signal and corresponding DC notch filter in accordance with the present invention;  
         [0024]      FIG. 9  is a diagram of OFDM sub-carrier channel allocations for a narrow channel in accordance with the present invention;  
         [0025]      FIG. 10  is a schematic block diagram of multiple-input-multiple-output wireless communications in accordance with the present invention; and  
         [0026]      FIG. 11  is a schematic block diagram of a wireless communication device in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]      FIG. 2  is a schematic block diagram illustrating a communication system 10 that includes a plurality of base stations and/or access points  12 - 16 , a plurality of wireless communication devices  18 - 32  and a network hardware component  34 . The wireless communication devices  18 - 32  may be laptop host computers  18  and  26 , personal digital assistant hosts  20  and  30 , personal computer hosts  24  and  32  and/or cellular telephone hosts  22  and  28 . The details of the wireless communication devices will be described in greater detail with reference to  FIG. 3 .  
         [0028]     The base stations or access points  12 - 16  are operably coupled to the network hardware  34  via local area network connections  36 ,  38  and  40 . The network hardware  34 , which may be a router, switch, bridge, modem, system controller, et cetera provides a wide area network connection  42  for the communication system  10 . Each of the base stations or access points  12 - 16  has an associated antenna or antenna array to communicate with the wireless communication devices in its area. Typically, the wireless communication devices register with a particular base station or access point  12 - 14  to receive services from the communication system  10 . For direct connections (i.e., point-to-point communications), wireless communication devices communicate directly via an allocated channel.  
         [0029]     Typically, base stations are used for cellular telephone systems and like-type systems, while access points are used for in-home or in-building wireless networks. Regardless of the particular type of communication system, each wireless communication device includes a built-in radio and/or is coupled to a radio. Note that one or more of the access points and affiliated wireless communication devices may be within a building.  
         [0030]      FIG. 3  is a schematic block diagram illustrating a wireless communication device that includes the host device  18 - 32  and an associated radio  60 . For cellular telephone hosts, the radio  60  is a built-in component. For personal digital assistants hosts, laptop hosts, and/or personal computer hosts, the radio  60  may be built-in or an externally coupled component.  
         [0031]     As illustrated, the host device  18 - 32  includes a processing module  50 , memory  52 , a radio interface  54 , an input interface  58 , and an output interface  56 . The processing module  50  and memory  52  execute the corresponding instructions that are typically done by the host device. For example, for a cellular telephone host device, the processing module  50  performs the corresponding communication functions in accordance with a particular cellular telephone standard.  
         [0032]     The radio interface  54  allows data to be received from and sent to the radio  60 . For data received from the radio  60  (e.g., inbound data), the radio interface  54  provides the data to the processing module  50  for further processing and/or routing to the output interface  56 . The output interface  56  provides connectivity to an output display device such as a display, monitor, speakers, et cetera such that the received data may be displayed. The radio interface  54  also provides data from the processing module  50  to the radio  60 . The processing module  50  may receive the outbound data from an input device such as a keyboard, keypad, microphone, et cetera via the input interface  58  or generate the data itself. For data received via the input interface  58 , the processing module  50  may perform a corresponding host function on the data and/or route it to the radio  60  via the radio interface  54 .  
         [0033]     Radio  60  includes a host interface  62 , digital receiver processing module  64 , an analog-to-digital converter  66 , a filtering/gain module  68 , an IF mixing down conversion stage  70 , a receiver filter  71 , a low noise amplifier  72 , a transmitter/receiver switch  73 , a local oscillation module  74 , memory  75 , a digital transmitter processing module  76 , a digital-to-analog converter  78 , a filtering/gain module  80 , an IF mixing up conversion stage  82 , a power amplifier  84 , a transmitter filter module  85 , and an antenna  86 . The antenna  86  may be a single antenna that is shared by the transmit and receive paths as regulated by the Tx/Rx switch  73 , or may include separate antennas for the transmit path and receive path. The antenna implementation will depend on the particular standard to which the wireless communication device is compliant.  
         [0034]     The digital receiver processing module  64  and the digital transmitter processing module  76 , in combination with operational instructions stored in memory  75 , execute digital receiver functions and digital transmitter functions, respectively. The digital receiver functions include, but are not limited to, digital intermediate frequency to baseband conversion, demodulation, constellation demapping, decoding, and/or descrambling. The digital transmitter functions include, but are not limited to, scrambling, encoding, constellation mapping, modulation, and/or digital baseband to IF conversion. The digital receiver and transmitter processing modules  64  and  76  may be implemented using a shared processing device, individual processing devices, 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  75  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, and/or any device that stores digital information. Note that when the processing module  64  and/or  76  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 is embedded with the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry.  
         [0035]     In operation, the radio  60  receives a stream of outbound data  94  from the host device via the host interface  62 . The host interface  62  routes the outbound data  94  to the digital transmitter processing module  76 , which processes the outbound data  94  in accordance with a particular wireless communication standard (e.g., IEEE 802.11, Bluetooth, et cetera) to produce outbound baseband signals  96 . The outbound baseband signals  96 , which include OFDM frames, will be digital base-band signals (e.g., have a zero IF) or a digital, low IF signals, where the low IF typically will be in the frequency range of one hundred kilohertz to a few megahertz.  
         [0036]     The digital-to-analog converter  78  converts the outbound baseband signals  96  from the digital domain to the analog domain. The filtering/gain module  80  filters and/or adjusts the gain of the analog signals prior to providing it to the IF mixing stage  82 . The IF mixing stage  82  converts the analog baseband or low IF signals into RF signals based on a transmitter local oscillation  83  provided by local oscillation module  74 . The power amplifier  84  amplifies the RF signals to produce outbound RF signals  98 , which are filtered by the transmitter filter module  85 . The antenna  86  transmits the outbound RF signals  98  to a targeted device such as a base station, an access point and/or another wireless communication device.  
         [0037]     The radio  60  also receives inbound RF signals  88  via the antenna  86 , which were transmitted by a base station, an access point, or another wireless communication device. The antenna  86  provides the inbound RF signals  88  to the receiver filter module  71  via the Tx/Rx switch  73 , where the Rx filter  71  bandpass filters the inbound RF signals  88 . The Rx filter  71  provides the filtered RF signals to low noise amplifier  72 , which amplifies the signals  88  to produce an amplified inbound RF signals. The low noise amplifier  72  provides the amplified inbound RF signals to the IF mixing module  70 , which directly converts the amplified inbound RF signals into an inbound low IF signals or baseband signals based on a receiver local oscillation  81  provided by local oscillation module  74 . The down conversion module  70  provides the inbound low IF signals or baseband signals to the filtering/gain module  68 . The filtering/gain module  68  filters and/or gains the inbound low IF signals or the inbound baseband signals to produce filtered inbound signals.  
         [0038]     The analog-to-digital converter  66  converts the filtered inbound signals from the analog domain to the digital domain to produce inbound baseband signals  90 , where the inbound baseband signals  90 , which include OFDM frames, will be digital base-band signals or digital low IF signals, where the low IF typically will be in the frequency range of one hundred kilohertz to a few megahertz.. The digital receiver processing module  64  decodes, descrambles, demaps, and/or demodulates the inbound baseband signals  90  to recapture a stream of inbound data  92  in accordance with the particular wireless communication standard being implemented by radio  60 . The host interface  62  provides the recaptured inbound data  92  to the host device  18 - 32  via the radio interface  54 .  
         [0039]     As one of average skill in the art will appreciate, the wireless communication device of  FIG. 3  may be implemented using one or more integrated circuits. For example, the host device may be implemented on one integrated circuit, the digital receiver processing module  64 , the digital transmitter processing module  76  and memory  75  may be implemented on a second integrated circuit, and the remaining components of the radio  60 , less the antenna  86 , may be implemented on a third integrated circuit. As an alternate example, the radio  60  may be implemented on a single integrated circuit. As yet another example, the processing module  50  of the host device and the digital receiver and transmitter processing modules  64  and  76  may be a common processing device implemented on a single integrated circuit. Further, the memory  52  and memory  75  may be implemented on a single integrated circuit and/or on the same integrated circuit as the common processing modules of processing module  50  and the digital receiver and transmitter processing module  64  and  76 .  
         [0040]      FIG. 4  is a diagram of a wireless communication between two wireless communication devices. As shown, a 1 st  wireless communication device includes a transmitter  100  and a 2 nd  communication device includes a receiver  102 . Each of the wireless communication devices may be implemented as previously described with reference to  FIG. 3 .  
         [0041]     As shown, the transmitter  100  receives a stream of outbound data  94  and converts it into outbound RF signals  98 . The outbound RF signals include OFDM frames  104  that are conveyed from the transmitter  100  to the receiver  102 . The receiver  102  receives the OFDM frames  104  as inbound RF signals  88  and converts them into a stream of inbound data  92 .  
         [0042]     An OFDM frame  104  includes a preamble section  106  and a data section  108 . The preamble section  106  includes training information  110  and signal field information  112 . The training information  110  may include, for example, for an 802.11a application or other  802 . 11  applications, a short training sequence, guard intervals and long training sequences. The signal information section  112  may be a signal field in accordance with 802.11a or other 802.11 specifications and provide information relating to the length of the OFDM frame  104 , data rate, et cetera. In addition, the signal information  112  may include an indication as to which of the plurality of sub-carriers in the data section of the OFDM frame will function as pilot signals or tones.  
         [0043]     The data section  108  includes a plurality of guard intervals (GI) and a plurality of data fields  114 - 118 . Each of the data fields  114 - 118  contains data that is carried within 64 sub-carriers of an OFDM frame. In one embodiment, as shown, data field  116  includes 64 sub-carriers centered about the RF frequency of the RF signals  98 . For a 20 MHz channel, the spacing of the sub-carriers is 312.5 KHz, which are represented by the arrow signals.  
         [0044]     As is further shown, some of the sub-carriers are not used. In particular sub-carrier  0 , sub-carriers  27 - 32  and sub-carriers − 27  through − 31  are not used. In this instance, only two pilot signals are used and are positioned at sub-carrier  21  and sub-carrier − 21 . In this embodiment, sub-carrier + 7  and − 7 , which in accordance with the 802.11a specification are used for pilot tones, are used to carry data. As such, more data may be represented within a particular data field by utilizing more of the sub-carriers for data conveyance and less for pilot signals.  
         [0045]      FIG. 5  illustrates an alternate sub-carrier allocation of an OFDM frame. In this instance, pilot signals are positioned at sub-carriers  7  and − 7  while sub-carriers + 21  and − 21  are used to carry data. Note that from data field to data field within an OFDM frame, the sub-carrier allocation may vary as shown in  FIG. 4  to  FIG. 5  on a field-by-field basis, on some pre-described pattern, or may be fixed to the allocation as shown in  FIG. 4  or  FIG. 5 .  
         [0046]      FIG. 6  illustrates another sub-carrier allocation within an OFDM frame. In this instance, sub-carrier  0 ,  27 - 32  and − 27  through − 31  are not used. Sub-carriers  1 - 6 ,  8 - 20 ,  22 - 26 , − 1  through − 6 , − 8  through − 20 , and − 22  through − 26  are used to carry data. In this embodiment, sub-carriers ± 7  and sub-carriers ± 21  may be used to carry data and/or a pilot signal. As such, 0 to 4 of the sub-carriers ± 7  and ± 21  may be used to carry a pilot tone.  
         [0047]      FIG. 7  is a table illustrating the characteristics of a physical layer that operates consistently with an embodiment of the present invention. The physical layer of the present invention resides within a 10 MHz channel and is OFDM based. It has many similarities to the IEEE 802.11(a) physical layer and with some differences.  FIG. 3  compares the physical layer o the 10 MHz OFDM physical layer of the present invention to the IEEE 802.11(a) physical layer. The 10 MHz OFDM physical layer of the present invention may operate in various frequency bands including the bands of 4.9-5.0 GHz and 5.03-5.091 GHz. The physical layer operates such that it has a maximum range of  3  Km, a maximum licensed transmit power of 250 mw; 2500 mw EIRP, and a maximum unlicensed transmit power of 100 mw.  
         [0048]     Path Loss (obstructed channel) model for the physical layer is described by: L(d)=L(d 0 )+10n log 10 (d/d 0 )+X σ  where  
         [0049]     d 0 =1;L(d 0 )=46.6 dB,n=2.58; σ=9.31 with a typical value at 500 of 116 dB ±9.3 dB. The delay spread for the physical layer has a mean of mean of 275.9 ns and a standard deviation of 352 ns. Because the physical layer has a longer delay spread than the IEEE 802.11(a) physical layer (50 nS delay spread channel), a guard interval (cyclic prefix) is required. Further, because the physical layer has a greater path loss than the IEEE 802.11(a) physical layer, a receiver supporting the physical layer needs improved sensitivity.  
         [0050]     As contrasted to the IEEE 802.11(a) physical layer, with the receiver bandwidth reduced by a factor of 2, the SNR of the physical layer is improved by 3 dB. The length of the guard interval (cyclical prefix) is doubled to 1.6 microseconds. The symbol length is doubled to maintain the same amount of guard interval overhead as IEEE 802.11(a). A 64 point Fast Fourier Transform (FFT) may also be used with the physical layer, as it is used with the IEEE 802.11(a) physical layer.  
         [0051]      FIG. 8  is a graph illustrating the manner in which tones of the physical layer are managed according to an embodiment of the present invention. Because the bandwidth of the physical layer is reduced (as compared to the bandwidth of the IEEE 802.11(a) physical layer), the center tones, tone − 1  and tone + 1  are nearer DC. Many receiver designs incorporate a notch filter at DC. Normal frequency offset between supported mobile terminals effectively moves this notch away from DC. With the closer tone spacing, the effect of frequency offset is more severe. In a most severe operating condition, frequency offset may cause the notch filter to remove a portion of either tone − 1  or tone + 1 .  
         [0052]     Thus, according to the present invention, the inner two data sub-carriers (tone − 1  and tone + 1 ) are removed/not used to accommodate the frequency offsets. Data that is specified to be carried on tones − 1  and + 1  by the IEEE 802.11(a) physical layer is moved to tones − 21 , − 7 ,  7 , and  21  such that it is alternated with the pilots on these sub-carriers. With this modification, the physical layer includes a dead zone width of 407.28 KHz+ the receiver Notch Bandwidth.  
         [0053]     In one operation, the physical layer alternates the tones used according to k=symbol index mod 6 (starting from SIGNAL symbol as zero): 
        k=0; data on tones {− 21 , − 7 } k=1; {− 21 ,  7 }    k=2; {− 21 ,  21 } k=3; {- 7 , 7 }    k=4; {− 7 ,  21 } k=5; { 7 ,  21 }       
 
         [0057]     This solution maintains frequency diversity of pilots. Further, Short and Long training symbols are generated the same way as in IEEE 802.11(a) section 17.3.3, except time period for IFFT is lengthened by a factor of 2. PHY rates of 3, 4.5, 6, 9, 12, 18, 24, 27 Mbps are supported.  
         [0058]     These longer symbol times and air propagation times require MAC timing changes (as compared to the IEEE 802.11(a) physical layer. These timing changes are summarized by: 
        aCCATime increases from 4 to 8 microseconds     aAirPropagationTime increases from &lt;&lt;1 microsecond to 2 microseconds     aSlotTIME=14 microseconds     aSIFSTIME=16 microseconds (no change)     PIFS=30 microseconds (SIFS+SLOT)     DIFS=44 microseconds (SIFS+2*SLOT)        
 
         [0065]      FIG. 9  is a diagram of sub-carrier allocation of an OFDM frame for a narrow channel. The narrow channel may have a bandwidth less than 20 MHz and in one embodiment may be 10 MHz. In this instance, sub-carriers  0  and +and − 1  are not used because of the issue discussed with reference to  FIG. 8 . In addition, sub-carriers  27 - 32  and − 27  through − 31  are not used. In this instance, to replace the loss of sub-carriers − 1  and + 1 , either sub-carrier + 7  and − 7  or + 21  and − 21  are used to carry data while the other pair is used to carry pilot tones. In this instance, sub-carriers + 1  and − 1  are carrying null data.  
         [0066]      FIG. 10  is a schematic block diagram of a multiple-input-multiple-output (MIMO) wireless communication. In this instance, a transmitter  120  of a wireless communication device receives an outbound stream of data  124  and converts it into a plurality of RF signals that each includes a plurality of OFDM frames  126 . The receiver  122  receives the plurality of RF signals and converts them into an inbound stream of data  128 . The transmitter  120  and receiver  122  will be further described with reference to the wireless communication device of  FIG. 11 .  
         [0067]     In this illustration, each of the OFDM frames  126  may have a sub-carrier allocation as illustrated with reference to  FIG. 6 . Further, from path-to-path, the sub-carrier allocation may be different. For example, if there are four wireless communication paths between transmitter  120  and receiver  122 , each of the four paths may have a different sub-carrier allocation. For example, one wireless path may have no pilot tones, another may have four pilot tones, and the remaining two may have + and − 7  for one pairing and + and − 21  for another pairing. As one of ordinary skill in the art will appreciate, because of the multiple communication paths between transmitter  120  and  122 , the pilot tones from one path may be utilized to synchronize and/or train another path, or they may be used in conjunction to synchronize and/or train the multiple paths.  
         [0068]      FIG. 11  is a schematic block diagram illustrating a wireless communication device that includes the host device  18 - 32  and an associated radio  160 . For cellular telephone hosts, the radio  160  is a built-in component. For personal digital assistants hosts, laptop hosts, and/or personal computer hosts, the radio  60  may be built-in or an externally coupled component.  
         [0069]     As illustrated, the host device  18 - 32  includes a processing module  50 , memory  52 , radio interface  54 , input interface  58  and output interface  56 . The processing module  50  and memory  52  execute the corresponding instructions that are typically done by the host device. For example, for a cellular telephone host device, the processing module  50  performs the corresponding communication functions in accordance with a particular cellular telephone standard.  
         [0070]     The radio interface  54  allows data to be received from and sent to the radio  60 . For data received from the radio  60  (e.g., inbound data), the radio interface  54  provides the data to the processing module  50  for further processing and/or routing to the output interface  56 . The output interface  56  provides connectivity to an output display device such as a display, monitor, speakers, et cetera such that the received data may be displayed. The radio interface  54  also provides data from the processing module  50  to the radio  60 . The processing module  50  may receive the outbound data from an input device such as a keyboard, keypad, microphone, et cetera via the input interface  58  or generate the data itself. For data received via the input interface  58 , the processing module  50  may perform a corresponding host function on the data and/or route it to the radio  160  via the radio interface  54 .  
         [0071]     Radio  160  includes a host interface  162 , a baseband processing module  164 , memory  166 , a plurality of radio frequency (RF) transmitters  168 - 172 , a transmit/receive (T/R) module  174 , a plurality of antennas  182 - 186 , a plurality of RF receivers  176 - 180 , and a local oscillation module  200 . The baseband processing module  164 , in combination with operational instructions stored in memory  166 , execute digital receiver functions and digital transmitter functions, respectively. The digital receiver functions include, but are not limited to, digital intermediate frequency to baseband conversion, demodulation, constellation demapping, decoding, de-interleaving, fast Fourier transform, cyclic prefix removal, space and time decoding, and/or descrambling. The digital transmitter functions include, but are not limited to, scrambling, encoding, interleaving, constellation mapping, modulation, inverse fast Fourier transform, cyclic prefix addition, space and time encoding, and/or digital baseband to IF conversion. The baseband processing modules  164  may be implemented using one or more 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  166  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, and/or any device that stores digital information. Note that when the processing module  64  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 is embedded with the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry.  
         [0072]     In operation, the radio  160  receives a stream of outbound data  188  from the host device via the host interface  162 . The baseband processing module  164  receives the stream of outbound data  188  and, based on a mode selection signal  202 , produces one or more outbound symbol streams  190 , each of which includes OFDM frames. The mode selection signal  202  will indicate a particular mode as are illustrated in the mode selection tables, which appear at the end of the detailed discussion. For example, the mode selection signal  202 , with reference to table 1 may indicate a frequency band of 2.4 GHz, a channel bandwidth of 20 or 22 MHz and a maximum bit rate of 54 megabits-per-second. In this general category, the mode selection signal will further indicate a particular rate ranging from 1 megabit-per-second to 54 megabits-per-second. In addition, the mode selection signal will indicate a particular type of modulation, which includes, but is not limited to, Barker Code Modulation, BPSK, QPSK, CCK, 16 QAM and/or 64 QAM. As is further illustrated in table 1, a code rate is supplied as well as number of coded bits per subcarrier (NBPSC), coded bits per OFDM symbol (NCBPS), data bits per OFDM symbol (NDBPS), error vector magnitude in decibels (EVM), sensitivity which indicates the maximum receive power required to obtain a target packet error rate (e.g., 10% for IEEE 802.11a), adjacent channel rejection (ACR), and an alternate adjacent channel rejection (AACR).  
         [0073]     The mode selection signal  202  may also indicate a particular channelization for the corresponding mode which for the information in table 1 is illustrated in table 2. As shown, table 2 includes a channel number and corresponding center frequency. The mode select signal may further indicate a power spectral density mask value which for table 1 is illustrated in table 3. The mode select signal  202  may alternatively indicate rates within table 4 that has a 5 GHz frequency band, 20 MHz channel bandwidth and a maximum bit rate of 54 megabits-per-second. If this is the particular mode select, the channelization is illustrated in table 5. As a further alternative, the mode select signal  102  may indicate a 2.4 GHz frequency band, 20 MHz channels and a maximum bit rate of 192 megabits-per-second as illustrated in table 6. In table 6, a number of antennas may be utilized to achieve the higher bandwidths. In this instance, the mode select would further indicate the number of antennas to be utilized. Table 7 illustrates the channelization for the set-up of table 6. Table 8 illustrates yet another mode option where the frequency band is 2.4 GHz, the channel bandwidth is 20 MHz and the maximum bit rate is 192 megabits-per-second. The corresponding table 8 includes various bit rates ranging from 12 megabits-per-second to 216 megabits-per-second utilizing 2-4 antennas and a spatial time encoding rate as indicated. Table 9 illustrates the channelization for table 8. The mode select signal  202  may further indicate a particular operating mode as illustrated in table 10, which corresponds to a 5 GHz frequency band having 40 MHz frequency band having 40 MHz channels and a maximum bit rate of 486 megabits-per-second. As shown in table 10, the bit rate may range from 13.5 megabits-per-second to 486 megabits-per-second utilizing 1-4 antennas and a corresponding spatial time code rate. Table 10 further illustrates a particular modulation scheme code rate and NBPSC values. Table 11 provides the power spectral density mask for table 10 and table 12 provides the channelization for table 10.  
         [0074]     The baseband processing module  164 , based on the mode selection signal  202  produces the one or more outbound symbol streams  190 , which include OFDM frames as described herein, from the outbound data  188 . For example, if the mode selection signal  202  indicates that a single transmit antenna is being utilized for the particular mode that has been selected, the baseband processing module  164  will produce a single outbound symbol stream  190 . Alternatively, if the mode select signal indicates 2, 3 or 4 antennas, the baseband processing module  164  will produce  2 ,  3  or  4  outbound symbol streams  190  corresponding to the number of antennas from the outbound data  188 .  
         [0075]     Depending on the number of outbound streams  190  produced by the baseband module  164 , a corresponding number of the RF transmitters  168 - 172  will be enabled to convert the outbound symbol streams  190  into outbound RF signals  192 . The transmit/receive module  174  receives the outbound RF signals  192  and provides each outbound RF signal to a corresponding antenna  182 - 186 .  
         [0076]     When the radio  160  is in the receive mode, the transmit/receive module  174  receives one or more inbound RF signals via the antennas  182 - 186 . The T/R module  174  provides the inbound RF signals  194  to one or more RF receivers  176 - 180 . The RF receivers  176 - 180  convert the inbound RF signals  194  into a corresponding number of inbound symbol streams  196 , which include OFDM frames as described herein. The number of inbound symbol streams  196  will correspond to the particular mode in which the data was received (recall that the mode may be any one of the modes illustrated in tables 1-12). The baseband processing module  160  receives the inbound symbol streams  190  and converts them into a stream of inbound data  198 , which is provided to the host device  18 - 32  via the host interface  162 .  
         [0077]     As one of average skill in the art will appreciate, the wireless communication device of  FIG. 11  may be implemented using one or more integrated circuits. For example, the host device may be implemented on one integrated circuit, the baseband processing module  164  and memory  166  may be implemented on a second integrated circuit, and the remaining components of the radio  160 , less the antennas  182 - 186 , may be implemented on a third integrated circuit. As an alternate example, the radio  160  may be implemented on a single integrated circuit. As yet another example, the processing module  150  of the host device and the baseband processing module  164  may be a common processing device implemented on a single integrated circuit. Further, the memory  152  and memory  166  may be implemented on a single integrated circuit and/or on the same integrated circuit as the common processing modules of processing module  150  and the baseband processing module  164 .  
         [0078]     As one of ordinary 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 and/or relativity between items. 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. Such relativity between items ranges from a difference of a few percent to magnitude differences. As one of ordinary 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 ordinary 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 ordinary 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 .  
         [0079]     The preceding discussion has presented various methods and apparatuses for generating and receiving OFDM frames. As one of ordinary 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.  
         [0080]     Mode Selection Tables:  
                                                                                                   TABLE 1                           2.4 GHz, 20/22 MHz channel BW, 54 Mbps max bit rate                    Code                                   Rate   Modulation   Rate   NBPSC   NCBPS   NDBPS   EVM   Sensitivity   ACR   AACR                        Barker                                       1   BPSK           Barker       2   QPSK       5.5   CCK       6   BPSK   0.5   1   48   24   −5   −82   16   32       9   BPSK   0.75   1   48   36   −8   −81   15   31       11   CCK       12   QPSK   0.5   2   96   48   −10   −79   13   29       18   QPSK   0.75   2   96   72   −13   −77   11   27       24   16-QAM   0.5   4   192   96   −16   −74   8   24       36   16-QAM   0.75   4   192   144   −19   −70   4   20       48   64-QAM   0.666   6   288   192   −22   −66   0   16       54   64-QAM   0.75   6   288   216   −25   −65   −1   15                  
 
         [0081]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                   
               
               
                 Channelization for Table 1 
               
             
          
           
               
                   
                   
                 Frequency 
               
               
                   
                 Channel 
                 (MHz) 
               
               
                   
                   
               
             
          
           
               
                   
                 1 
                 2412 
               
               
                   
                 2 
                 2417 
               
               
                   
                 3 
                 2422 
               
               
                   
                 4 
                 2427 
               
               
                   
                 5 
                 2432 
               
               
                   
                 6 
                 2437 
               
               
                   
                 7 
                 2442 
               
               
                   
                 8 
                 2447 
               
               
                   
                 9 
                 2452 
               
               
                   
                 10 
                 2457 
               
               
                   
                 11 
                 2462 
               
               
                   
                 12 
                 2467 
               
               
                   
                   
               
             
          
         
       
     
         [0082]    
       
         
               
             
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                   
               
               
                 Power Spectral Density (PSD) Mask for Table 1 
               
             
          
           
               
                   
                 PSD Mask 
                 1 
               
               
                   
                   
               
               
                   
                 Frequency Offset 
                 dBr 
               
               
                   
                     −9 MHz to 9 MHz 
                 0 
               
               
                   
                 +/−11 MHz 
                 −20 
               
               
                   
                 +/−20 MHz 
                 −28 
               
               
                   
                 +/−30 MHz and 
                 −50 
               
               
                   
                 greater 
               
               
                   
                   
               
             
          
         
       
     
         [0083]    
       
         
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                   
               
               
                 5 GHz, 20 MHz channel BW, 54 Mbps max bit rate 
               
             
          
           
               
                   
                   
                 Code 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Rate 
                 Modulation 
                 Rate 
                 NBPSC 
                 NCBPS 
                 NDBPS 
                 EVM 
                 Sensitivity 
                 ACR 
                 AACR 
               
               
                   
               
             
          
           
               
                 6 
                 BPSK 
                 0.5 
                 1 
                 48 
                 24 
                 −5 
                 −82 
                 16 
                 32 
               
               
                 9 
                 BPSK 
                 0.75 
                 1 
                 48 
                 36 
                 −8 
                 −81 
                 15 
                 31 
               
               
                 12 
                 QPSK 
                 0.5 
                 2 
                 96 
                 48 
                 −10 
                 −79 
                 13 
                 29 
               
               
                 18 
                 QPSK 
                 0.75 
                 2 
                 96 
                 72 
                 −13 
                 −77 
                 11 
                 27 
               
               
                 24 
                 16-QAM 
                 0.5 
                 4 
                 192 
                 96 
                 −16 
                 −74 
                 8 
                 24 
               
               
                 36 
                 16-QAM 
                 0.75 
                 4 
                 192 
                 144 
                 −19 
                 −70 
                 4 
                 20 
               
               
                 48 
                 64-QAM 
                 0.666 
                 6 
                 288 
                 192 
                 −22 
                 −66 
                 0 
                 16 
               
               
                 54 
                 64-QAM 
                 0.75 
                 6 
                 288 
                 216 
                 −25 
                 −65 
                 −1 
                 15 
               
               
                   
               
             
          
         
       
     
         [0084]    
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                   
               
               
                 Channelization for Table 4 
               
             
          
           
               
                   
                 Frequency 
                   
                   
                 Frequency 
                   
               
               
                 Channel 
                 (MHz) 
                 Country 
                 Channel 
                 (MHz) 
                 Country 
               
               
                   
               
             
          
           
               
                 240 
                 4920 
                 Japan 
                   
                   
                   
               
               
                 244 
                 4940 
                 Japan 
               
               
                 248 
                 4960 
                 Japan 
               
               
                 252 
                 4980 
                 Japan 
               
               
                 8 
                 5040 
                 Japan 
               
               
                 12 
                 5060 
                 Japan 
               
               
                 16 
                 5080 
                 Japan 
               
               
                 36 
                 5180 
                 USA/Europe 
                 34 
                 5170 
                 Japan 
               
               
                 40 
                 5200 
                 USA/Europe 
                 38 
                 5190 
                 Japan 
               
               
                 44 
                 5220 
                 USA/Europe 
                 42 
                 5210 
                 Japan 
               
               
                 48 
                 5240 
                 USA/Europe 
                 46 
                 5230 
                 Japan 
               
               
                 52 
                 5260 
                 USA/Europe 
               
               
                 56 
                 5280 
                 USA/Europe 
               
               
                 60 
                 5300 
                 USA/Europe 
               
               
                 64 
                 5320 
                 USA/Europe 
               
               
                 100 
                 5500 
                 USA/Europe 
               
               
                 104 
                 5520 
                 USA/Europe 
               
               
                 108 
                 5540 
                 USA/Europe 
               
               
                 112 
                 5560 
                 USA/Europe 
               
               
                 116 
                 5580 
                 USA/Europe 
               
               
                 120 
                 5600 
                 USA/Europe 
               
               
                 124 
                 5620 
                 USA/Europe 
               
               
                 128 
                 5640 
                 USA/Europe 
               
               
                 132 
                 5660 
                 USA/Europe 
               
               
                 136 
                 5680 
                 USA/Europe 
               
               
                 140 
                 5700 
                 USA/Europe 
               
               
                 149 
                 5745 
                 USA 
               
               
                 153 
                 5765 
                 USA 
               
               
                 157 
                 5785 
                 USA 
               
               
                 161 
                 5805 
                 USA 
               
               
                 165 
                 5825 
                 USA 
               
               
                   
               
             
          
         
       
     
         [0085]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 6 
               
             
             
               
                   
               
               
                   
               
               
                 2.4 GHz, 20 MHz channel BW, 192 Mbps max bit rate 
               
             
          
           
               
                   
                 TX 
                 ST 
                   
                   
                   
                   
                   
               
               
                   
                 Anten- 
                 Code 
                   
                 Code 
               
               
                 Rate 
                 nas 
                 Rate 
                 Modulation 
                 Rate 
                 NBPSC 
                 NCBPS 
                 NDBPS 
               
               
                   
               
             
          
           
               
                 12 
                 2 
                 1 
                 BPSK 
                 0.5 
                 1 
                 48 
                 24 
               
               
                 24 
                 2 
                 1 
                 QPSK 
                 0.5 
                 2 
                 96 
                 48 
               
               
                 48 
                 2 
                 1 
                 16-QAM 
                 0.5 
                 4 
                 192 
                 96 
               
               
                 96 
                 2 
                 1 
                 64-QAM 
                 0.666 
                 6 
                 288 
                 192 
               
               
                 108 
                 2 
                 1 
                 64-QAM 
                 0.75 
                 6 
                 288 
                 216 
               
               
                 18 
                 3 
                 1 
                 BPSK 
                 0.5 
                 1 
                 48 
                 24 
               
               
                 36 
                 3 
                 1 
                 QPSK 
                 0.5 
                 2 
                 96 
                 48 
               
               
                 72 
                 3 
                 1 
                 16-QAM 
                 0.5 
                 4 
                 192 
                 96 
               
               
                 144 
                 3 
                 1 
                 64-QAM 
                 0.666 
                 6 
                 288 
                 192 
               
               
                 162 
                 3 
                 1 
                 64-QAM 
                 0.75 
                 6 
                 288 
                 216 
               
               
                 24 
                 4 
                 1 
                 BPSK 
                 0.5 
                 1 
                 48 
                 24 
               
               
                 48 
                 4 
                 1 
                 QPSK 
                 0.5 
                 2 
                 96 
                 48 
               
               
                 96 
                 4 
                 1 
                 16-QAM 
                 0.5 
                 4 
                 192 
                 96 
               
               
                 192 
                 4 
                 1 
                 64-QAM 
                 0.666 
                 6 
                 288 
                 192 
               
               
                 216 
                 4 
                 1 
                 64-QAM 
                 0.75 
                 6 
                 288 
                 216 
               
               
                   
               
             
          
         
       
     
         [0086]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 7 
               
             
             
               
                   
               
               
                   
               
               
                 Channelization for Table 6 
               
             
          
           
               
                   
                 Channel 
                 Frequency (MHz) 
               
               
                   
                   
               
             
          
           
               
                   
                 1 
                 2412 
               
               
                   
                 2 
                 2417 
               
               
                   
                 3 
                 2422 
               
               
                   
                 4 
                 2427 
               
               
                   
                 5 
                 2432 
               
               
                   
                 6 
                 2437 
               
               
                   
                 7 
                 2442 
               
               
                   
                 8 
                 2447 
               
               
                   
                 9 
                 2452 
               
               
                   
                 10 
                 2457 
               
               
                   
                 11 
                 2462 
               
               
                   
                 12 
                 2467 
               
               
                   
                   
               
             
          
         
       
     
         [0087]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 8 
               
             
             
               
                   
               
               
                   
               
               
                 5 GHz, 20 MHz channel BW, 192 Mbps max bit rate 
               
             
          
           
               
                   
                 TX 
                 ST 
                   
                   
                   
                   
                   
               
               
                   
                 Anten- 
                 Code 
                   
                 Code 
               
               
                 Rate 
                 nas 
                 Rate 
                 Modulation 
                 Rate 
                 NBPSC 
                 NCBPS 
                 NDBPS 
               
               
                   
               
             
          
           
               
                 12 
                 2 
                 1 
                 BPSK 
                 0.5 
                 1 
                 48 
                 24 
               
               
                 24 
                 2 
                 1 
                 QPSK 
                 0.5 
                 2 
                 96 
                 48 
               
               
                 48 
                 2 
                 1 
                 16-QAM 
                 0.5 
                 4 
                 192 
                 96 
               
               
                 96 
                 2 
                 1 
                 64-QAM 
                 0.666 
                 6 
                 288 
                 192 
               
               
                 108 
                 2 
                 1 
                 64-QAM 
                 0.75 
                 6 
                 288 
                 216 
               
               
                 18 
                 3 
                 1 
                 BPSK 
                 0.5 
                 1 
                 48 
                 24 
               
               
                 36 
                 3 
                 1 
                 QPSK 
                 0.5 
                 2 
                 96 
                 48 
               
               
                 72 
                 3 
                 1 
                 16-QAM 
                 0.5 
                 4 
                 192 
                 96 
               
               
                 144 
                 3 
                 1 
                 64-QAM 
                 0.666 
                 6 
                 288 
                 192 
               
               
                 162 
                 3 
                 1 
                 64-QAM 
                 0.75 
                 6 
                 288 
                 216 
               
               
                 24 
                 4 
                 1 
                 BPSK 
                 0.5 
                 1 
                 48 
                 24 
               
               
                 48 
                 4 
                 1 
                 QPSK 
                 0.5 
                 2 
                 96 
                 48 
               
               
                 96 
                 4 
                 1 
                 16-QAM 
                 0.5 
                 4 
                 192 
                 96 
               
               
                 192 
                 4 
                 1 
                 64-QAM 
                 0.666 
                 6 
                 288 
                 192 
               
               
                 216 
                 4 
                 1 
                 64-QAM 
                 0.75 
                 6 
                 288 
                 216 
               
               
                   
               
             
          
         
       
     
         [0088]    
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 9 
               
             
             
               
                   
               
               
                   
               
               
                 channelization for Table 8 
               
             
          
           
               
                   
                 Frequency 
                   
                   
                 Frequency 
                   
               
               
                 Channel 
                 (MHz) 
                 Country 
                 Channel 
                 (MHz) 
                 Country 
               
               
                   
               
             
          
           
               
                 240 
                 4920 
                 Japan 
                   
                   
                   
               
               
                 244 
                 4940 
                 Japan 
               
               
                 248 
                 4960 
                 Japan 
               
               
                 252 
                 4980 
                 Japan 
               
               
                 8 
                 5040 
                 Japan 
               
               
                 12 
                 5060 
                 Japan 
               
               
                 16 
                 5080 
                 Japan 
               
               
                 36 
                 5180 
                 USA/Europe 
                 34 
                 5170 
                 Japan 
               
               
                 40 
                 5200 
                 USA/Europe 
                 38 
                 5190 
                 Japan 
               
               
                 44 
                 5220 
                 USA/Europe 
                 42 
                 5210 
                 Japan 
               
               
                 48 
                 5240 
                 USA/Europe 
                 46 
                 5230 
                 Japan 
               
               
                 52 
                 5260 
                 USA/Europe 
               
               
                 56 
                 5280 
                 USA/Europe 
               
               
                 60 
                 5300 
                 USA/Europe 
               
               
                 64 
                 5320 
                 USA/Europe 
               
               
                 100 
                 5500 
                 USA/Europe 
               
               
                 104 
                 5520 
                 USA/Europe 
               
               
                 108 
                 5540 
                 USA/Europe 
               
               
                 112 
                 5560 
                 USA/Europe 
               
               
                 116 
                 5580 
                 USA/Europe 
               
               
                 120 
                 5600 
                 USA/Europe 
               
               
                 124 
                 5620 
                 USA/Europe 
               
               
                 128 
                 5640 
                 USA/Europe 
               
               
                 132 
                 5660 
                 USA/Europe 
               
               
                 136 
                 5680 
                 USA/Europe 
               
               
                 140 
                 5700 
                 USA/Europe 
               
               
                 149 
                 5745 
                 USA 
               
               
                 153 
                 5765 
                 USA 
               
               
                 157 
                 5785 
                 USA 
               
               
                 161 
                 5805 
                 USA 
               
               
                 165 
                 5825 
                 USA 
               
               
                   
               
             
          
         
       
     
         [0089]    
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 10 
               
             
             
               
                   
               
               
                   
               
               
                 5 GHz, with 40 MHz channels and max bit rate of 486 Mbps 
               
             
          
           
               
                   
                 TX 
                 ST Code 
                   
                 Code 
                   
               
               
                 Rate 
                 Antennas 
                 Rate 
                 Modulation 
                 Rate 
                 NBPSC 
               
               
                   
               
             
          
           
               
                 13.5 Mbps  
                 1 
                 1 
                 BPSK 
                 0.5 
                 1 
               
               
                  27 Mbps 
                 1 
                 1 
                 QPSK 
                 0.5 
                 2 
               
               
                  54 Mbps 
                 1 
                 1 
                 16-QAM 
                 0.5 
                 4 
               
               
                 108 Mbps 
                 1 
                 1 
                 64-QAM 
                 0.666 
                 6 
               
               
                 121.5 Mbps   
                 1 
                 1 
                 64-QAM 
                 0.75 
                 6 
               
               
                  27 Mbps 
                 2 
                 1 
                 BPSK 
                 0.5 
                 1 
               
               
                  54 Mbps 
                 2 
                 1 
                 QPSK 
                 0.5 
                 2 
               
               
                 108 Mbps 
                 2 
                 1 
                 16-QAM 
                 0.5 
                 4 
               
               
                 216 Mbps 
                 2 
                 1 
                 64-QAM 
                 0.666 
                 6 
               
               
                 243 Mbps 
                 2 
                 1 
                 64-QAM 
                 0.75 
                 6 
               
               
                 40.5 Mbps  
                 3 
                 1 
                 BPSK 
                 0.5 
                 1 
               
               
                  81 Mbps 
                 3 
                 1 
                 QPSK 
                 0.5 
                 2 
               
               
                 162 Mbps 
                 3 
                 1 
                 16-QAM 
                 0.5 
                 4 
               
               
                 324 Mbps 
                 3 
                 1 
                 64-QAM 
                 0.666 
                 6 
               
               
                 365.5 Mbps   
                 3 
                 1 
                 64-QAM 
                 0.75 
                 6 
               
               
                  54 Mbps 
                 4 
                 1 
                 BPSK 
                 0.5 
                 1 
               
               
                 108 Mbps 
                 4 
                 1 
                 QPSK 
                 0.5 
                 2 
               
               
                 216 Mbps 
                 4 
                 1 
                 16-QAM 
                 0.5 
                 4 
               
               
                 432 Mbps 
                 4 
                 1 
                 64-QAM 
                 0.666 
                 6 
               
               
                 486 Mbps 
                 4 
                 1 
                 64-QAM 
                 0.75 
                 6 
               
               
                   
               
             
          
         
       
     
         [0090]    
       
         
               
             
               
               
               
             
           
               
                 TABLE 11 
               
             
             
               
                   
               
               
                   
               
               
                 Power Spectral Density (PSD) mask for Table 10 
               
             
          
           
               
                   
                 PSD Mask 
                 2 
               
               
                   
                   
               
               
                   
                 Frequency Offset 
                 dBr 
               
               
                   
                    −19 MHz to 19 MHz 
                 0 
               
               
                   
                 +/−21 MHz 
                 −20 
               
               
                   
                 +/−30 MHz 
                 −28 
               
               
                   
                 +/−40 MHz and 
                 −50 
               
               
                   
                 greater 
               
               
                   
                   
               
             
          
         
       
     
         [0091]    
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 12 
               
             
             
               
                   
               
               
                   
               
               
                 Channelization for Table 10 
               
             
          
           
               
                   
                 Frequency 
                   
                   
                 Frequency 
                   
               
               
                 Channel 
                 (MHz) 
                 Country 
                 Channel 
                 (MHz) 
                 County 
               
               
                   
               
             
          
           
               
                 242 
                 4930 
                 Japan 
                   
                   
                   
               
               
                 250 
                 4970 
                 Japan 
               
               
                 12 
                 5060 
                 Japan 
               
               
                 38 
                 5190 
                 USA/Europe 
                 36 
                 5180 
                 Japan 
               
               
                 46 
                 5230 
                 USA/Europe 
                 44 
                 5520 
                 Japan 
               
               
                 54 
                 5270 
                 USA/Europe 
               
               
                 62 
                 5310 
                 USA/Europe 
               
               
                 102 
                 5510 
                 USA/Europe 
               
               
                 110 
                 5550 
                 USA/Europe 
               
               
                 118 
                 5590 
                 USA/Europe 
               
               
                 126 
                 5630 
                 USA/Europe 
               
               
                 134 
                 5670 
                 USA/Europe 
               
               
                 151 
                 5755 
                 USA 
               
               
                 159 
                 5795 
                 USA