Abstract:
A dual-mode ultra wideband (UWB) and wireless local area network (WLAN) communication transceiver is used to implement two disparate systems of UWB and WLAN communications within a single device. During the UWB mode, the communication transceiver sends and receives the UWB signal at very-high data rate with a relative short transmission range. During the WLAN mode, the communication transceiver sends and receives the WLAN signal at a relative low data rate, but with a longer transmission range. Thereby, trade-off benefits of the dual-mode UWB and WLAN communication transceiver can be mutually utilized to achieve seamless wireless broadband communications between two different standards.

Description:
BACKGROUND 
   This invention is generally relative to a dual-mode ultra wideband (UWB) and wireless local area network (WLAN) communications. 
   On Apr. 22, 2002, U.S. Federal Communications Commission (FCC) released the revision of Part 15 of the Commission&#39;s rules regarding UWB transmission systems to permit the marketing and operation of certain types of new products incorporating UWB technology. With appropriate technology, UWB devices can operate using spectrum occupied by existing radio service without causing interference, thereby permitting scare spectrum resources to be used more efficiently. The UWB technology offers significant benefits for Government, public safety, businesses and consumers under an unlicensed basis of operation spectrum. 
   The UWB devices can be classified into three types based on the operating restrictions: (1) imaging systems including ground penetrating radars and wall, through-wall, surveillance, and medical imaging device, (2) vehicular radar systems, and (3) communications and measurement systems. In general, FCC is adapting unwanted emission limits for the UWB devices that are significantly more stringent than those imposed on other Part 15 devices. In other words, FCC limits outdoor use of the UWB device devices to imaging systems, vehicular radar systems and handheld devices. Limiting the frequency bands, which is based on the −10 dB bandwidth of the UWB emission within certain UWB products, will be permitted to operate. For the communications and measurement systems, FCC provides a wide variety of the UWB devices, such as high-speed home and business networking devices as well as storage tank measurement devices under the Part 15 of the Commission&#39;s rules subject to certain frequency and power limitations. The UWB devices must operate in the frequency band from 3.1 GHz to 10.6 GHz. The UWB devices should also satisfy by the Part 15.209 limit, which sets emission limits for indoor and outdoor UWB systems, for the frequency band below 960 MHz, and the FCC&#39;s emission masks for the frequency band above 960 MHz. 
   For the indoor UWB communication operation, Table 1 lists the FCC indoor restrictions of the emission masks (dBm) along with the frequencies (GHz). 
   
     
       
             
             
             
           
         
             
                 
               TABLE 1 
             
             
                 
                 
             
             
                 
               Frequency (MHz) 
               EIRP (dBm) 
             
             
                 
                 
             
           
           
             
                 
                0–960 
               −41.3 
             
             
                 
                960–1610 
               −75.3 
             
             
                 
               1610–1990 
               −53.3 
             
             
                 
               1990–3100 
               −51.3 
             
             
                 
                3100–10600 
               −41.3 
             
             
                 
               Above 10600 
               −51.3 
             
             
                 
                 
             
           
        
       
     
   
   The outdoor handheld UWB communication devices are intended to operate in a peer-to-peer mode without restriction on location. However, the outdoor handheld UWB communication devices must operate in the frequency band from 3.1 GHz to 10.6 GHz as well, with an extremely conservative out of band emission masks to address interference with other communication devices. The outdoor handheld UWB communication devices are permitted to emit at or below the Part 15.209 limit in the frequency band below 960 MHz. The emissions above 960 MHz for the outdoor handheld UWB communication devices must conform to the following emission masks as shown in Table 2: 
   
     
       
             
             
             
           
         
             
                 
               TABLE 2 
             
             
                 
                 
             
             
                 
               Frequency (MHz) 
               EIRP (dBm) 
             
             
                 
                 
             
           
           
             
                 
                0–960 
               −41.3 
             
             
                 
                960–1610 
               −75.3 
             
             
                 
               1610–1900 
               −63.3 
             
             
                 
               1900–3100 
               −61.3 
             
             
                 
                3100–10600 
               −41.3 
             
             
                 
               Above 10600 
               −61.3 
             
             
                 
                 
             
           
        
       
     
   
   FCC proposed to define a UWB device as any device where the fractional bandwidth is greater than 0.25 based on the formula as follows: 
                     F   ⁢           ⁢   B     =     2   ⁢     (         f   H     -     f   L           f   H     +     f   L         )         ,           (   1   )               
where f H  and f L  are the upper and lower frequencies of the −10 dB emission points, respectively. The center frequency of the UWB transmission is defined as the average of the upper and lower −10 dB points. That is
 
                   F   C     =           f   H     -     f   L       2     .             (   2   )               
In addition, a minimum bandwidth of 500 MHz must be used for indoor and outdoor UWB devices regardless of center frequency.
 
   The indoor UWB communication devices must be designed to ensure that operation can only occur indoor according to the indoor emission masks in Table 1. The outdoor handheld UWB communication devices that may be employed for such activities as peer-to-peer operation must be designed according to the outdoor emission masks in Table 2. Both of the indoor and outdoor UWB communication devices can be used for wireless communications, particularly for short-range high-speed data transmissions suitable for broadband access to networks. 
   UWB communication transceiver for the indoor and outdoor operation can transmit and receive UWB signals by using one channel and/or up to 11 channels in parallel according to some embodiments of the present invention. Each channel of the UWB communication transceiver has a frequency bandwidth of 650 MHz that can transmit 40.625 Mega bits per second (Mbps). That is, a total of 11 channels are able to transmit 446.875 Mbps. The UWB communication transceiver also employs the orthogonal spread codes for all the channels. With 16 pseudorandom noise (PN) spread sequence codes for each bit, each channel achieves 650 Mega chips per second (Mcps). The UWB communication transceiver for the indoor and outdoor operation can transmit and receive the chip data rate up to 7.150 Giga chips per second (Gcps). 
   WLAN 802.11a is an IEEE standard for wireless LAN medium access control (MAC) and physical layer (PHY) specification and is also referred to as the high-speed physical layer in the 5 GHz band. The WLAN 802.11a standard specifies a PHY entity for an orthogonal frequency division multiplexing (OFDM) system. The radio frequency LAN communication system is initially aimed for the lower band of the 5.15–5.35 GHz and the upper band of the 5.725–5.825 GHz unlicensed national information structure (U-NII) bands, as regulated in the United States by the code of Federal Regulations under Title 47 and Section 15.407. The WLAN 802.11a communication system provides the data payload rate of 6, 9, 12, 18, 24, 36, 48 and 54 it/s Mbps. Also, the WLAN 802.111a communication system supports the transmitting and receiving at data rate of 6, 12, and 24 Mbps with mandatory. The WLAN 802.111a communication system uses 52 subcarriers with modulation of using binary or quadrature phase shift keying (BPSK/QPSK), 16-quadrature amplitude modulation (QAM), or 64-QAM. The forward error correction coding (FEC) of convolutional encoding is used with a coding rate of ½, ⅔, or ¾. 
   The UWB communication transceiver can achieve the transmission distance in a range of 3 meters to 10 meters since the UWB communication transceiver has to transmit the data with very-low power due to the restriction of FCC emission limitation for the indoor and outdoor operation. The UWB communication transceiver can transmit and receive a very-high data rate in the range from 40.625 to 446.875 Mbps according to some embodiments of the present invention. On the other hand, the WLAN 802.111a communication system can only transmit and receive the data rate in a range from 6 to 54 Mbps, but with a longer transmission distance up to 100 meters. 
   Since the UWB communication transceiver for the indoor and outdoor operation can transmit and receive the very-high data rate with the short-distance while the WLAN 802.111a communication system can transmit and receive the data up to a much longer distance than the UWB device, but has a lower transmission data rate for the device. Therefore, developing a dual-mode transceiver of the UWB communication system for the indoor and outdoor operation and the WLAN 802.11a communication system is very important since trade-offs of the transmission distance and data rate between the UWB and the WLAN 802.11a transceiver can be mutually utilized for benefits. This allows the UWB and WLAN 802.11a transceiver with co-existence in an environment. 
   Thus, there is a continuing need for a dual-mode UWB and WLAN 802.11a transceiver that operates using more than one standard and enables a user to use the same communication device in areas in which operate under different standards for the short-range wireless broadband communications. 
   SUMMARY 
   In accordance with one aspect, the dual-mode ultra wideband and wireless local area network transceiver includes a digital lowpass-shaping filter system coupled to a ultra wideband multichannel pseudorandom noise sequence mapping or coupled to a wireless local area network inverse fast Fourier transform and image/quadrature modulation, a dual-mode sampling frequency rate coupled to a digital-to-analog converter, and a switch to connect from the ultra wideband multichannel pseudorandom noise sequence mapping or the wireless local area network inverse fast Fourier transform and image/quadrature modulation to the digital lowpass-shaping filter system. 
   Other aspects are set forth in the accompanying detailed description and claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of one embodiment of a dual-mode UWB and WLAN 802.11a communication transceiver for wireless broadband communication in accordance with the present invention. 
       FIG. 2  is a block diagram of showing a dual-mode UWB and WLAN 802.11a communication transmitter according to some embodiments. 
       FIG. 3  is a block diagram of showing a dual-mode UWB and WLAN 802.11a sampling frequency rate for a common digital-to-analog (D/A) converter according to some embodiments. 
       FIG. 4  is a block diagram of showing a dual-mode digital transmission lowpass-shaping FIR filter system for the indoor and outdoor UWB and WLAN 802.11a communication transmitter according to some embodiments. 
       FIG. 5  is a block diagram of showing one embodiment of the WLAN 802.11a digital transmission lowpass-shaping FIR interpolation filter of the present invention. 
       FIG. 6  is a block diagram of showing dual-mode multichannel-based multi-carrier modulation system according to some embodiments. 
       FIG. 7  is a frequency spectrum of including 11 transmitter channels for the indoor UWB transceiver along with the indoor FCC emission mask limitation according to some embodiments. 
       FIG. 8  is a frequency spectrum of including 11 transmitter channel spectrums for the outdoor UWB transceiver along with the outdoor FCC emission mask limitation according to some embodiments. 
       FIG. 9  is two frequency spectrums of including 8 transmitter channels and 4 transmitter channels of the WLAN 802.11a for the lower and upper bands, respectively. 
       FIG. 10  is a block diagram of showing a dual-mode UWB and WLAN 802.11a communication receiver according to some embodiments. 
       FIG. 11  is a block diagram of showing a flowchart of implementing the dual-mode UWB and WLAN 802.11a communication transceiver according to some embodiments. 
   

   DETAILED DESCRIPTION 
   Some embodiments described herein are directed to a dual-mode UWB AND WLAN 802.11a communication transceiver. The dual-mode UWB and WLAN 802.11a communication transceiver may be implemented in hardware, such as in an Application Specific Integrated Circuits (ASIC), digital signal processor, field programmable gate array (FPGA), software, or a combination of hardware and software. 
     FIG. 1  illustrates the dual-mode UWB and WLAN 802.11a communication transceiver  100  in accordance with one embodiment of the present invention. This dual-mode UWB and WLAN 802.11a communication transceiver  100  includes a dual-mode UWB and WLAN multi-carrier RF section  114  that receives and/or transmits multichannel UWB and WLAN 802.11a signals from an antenna  110  or to an antenna  112 . The dual-mode UWB and WLAN multi-carrier RF section  114  is connected with an analog and digital interface section  116  that contains analog-to-digital (A/D) and digital-to-analog (D/A) converters. The analog and digital interface section  116  is coupled to an UWB and WLAN 802.11a digital processing section  118 , which performs dual-mode multichannel digital transmission and receiver filtering, rake processing, OFDM, channel estimator, spread/de-spread processing, interleave/de-interleave, and encoder/decoder processing. The UWB and WLAN 802.111a digital processing section  118  has an interface with a UWB or WLAN 802.111a network interface section  120  in which is coupled to a UWB or WLAN 802.11a network  122 . In accordance with one embodiment of the present invention, the transceiver  100  is the so-called dual-mode UWB and WLAN 802.11a communication transceiver that can both transmit and receive speech, audio, images and video and data information for the indoor and/or outdoor wireless broadband communications. 
     FIG. 2  is a block diagram of showing a dual-mode transmitter of the indoor and/or outdoor UWB and WLAN 802.11a communication transceiver  200  according to some embodiments. The transmitter system of the dual-mode UWB and WLAN 802.11a transceiver  200  is able to transmit either the UWB for indoor or outdoor signals with a very-high data rate in the range of 3–10 meters or the WLAN 802.11a signals with lower data rate in a longer range up to 100 meters. 
   During the UWB mode, the UWB transmitter  200  receives user data bits  210  with information data rate at 223.4375 Mbps. The information data bits  210  are passed through a ½-rate convolution encoder  212  that may produce the double data rate of 446.875 Mbps by adding redundancy bits. The bit data is then interleaved by using a block interleaver  214 . A switch  234  is connected to a position of  236 A under a software control unit  228 . Then, the output bits of the block interleaver  214  are formed 11 multichannels by using a multichannel PN sequence mapping  218 . The bit data rate of each channel is about 40.625 Mbps. The multichannel PN sequence mapping  218  is used to perform spreading for one bit data with 16 orthogonal spread sequence chips and to produce 650 Mcps for each channel under the software control unit  228 . A PN sequence look-up table  216  provides the unique orthogonal sequences for each channel spreading. A switch  240  that is controlled by using the software control unit  228  is connected with a position  238 A. Then chip data of each channel is sequentially passed through an outdoor digital lowpass shaping finite impulse response (FIR) filter system  220  to limit the frequency bandwidth with 650 MHz for each channel signal. Each channel signal is passed through a D/A converter  222 , which has the 6-bit resolution and sampling frequency rate of 1 GHz provided by a dual-mode sampling rate  240 . The software control unit  228  controls the dual-mode sampling rate  240 . The output chip data of each channel from the D/A converter  222  is then modulated with a multi-carrier by using a multichannel-based multi-carrier  224  with controlling from the software control unit  228 . Thus, the output analog signals of the multichannel-based multi-carrier  224  are passed a power amplifier (PA)  226  through an antenna into air. 
   During the WLAN 802.11a mode, the WLAN 802.11a transmitter  200  receives user data bits  210 , which are passed through a ½-rate, ⅔-rate or ¾-rate convolution encoder  212  that may produce 2-times or 3/2-times or 4/3-times data rate by adding redundancy bits. The symbol bit data is then interleaved by using the interleaver unit  214 . The switch  234 , which is controlled by using the software control unit  228 , is connected to a position  236 B. Then, the output bits of the interleaver unit  214  are formed the data in parallel to be used for a 64-point IFFT unit  230 . The output of the 64-point IFFT unit  230  is performed for an image/quadrature (I/Q) modulation  232 . The switch  240  that is controlled by using the software control unit  228  is connected with a position  238 B. Then output data of the I/Q modulation  232  is passed through the digital lowpass shaping FIR filter system  220  to limit the frequency bandwidth with 20 MHz for the channel signal. The channel signal is passed through the D/A converter  222 , which has the 6-bit resolution and the oversampling frequency rate of 480 MHz provided by the dual-mode sampling rate  240 . The software control unit  228  controls the dual-mode sampling rate  240 . The output from the D/A converter  222  is then modulated with a multi-carrier by using the multichannel-based multi-carrier  224  with controlling from the software control unit  228 . Thus, the output analog signals of the multichannel-based multi-carrier  224  are passed the power amplifier  226  through an antenna into air. 
   Referring to  FIG. 3  is a detailed block diagram  300  of showing the dual-mode sampling frequency rate  220  according to some embodiments. A UWB sampling frequency unit  310  supports the sampling rate at 1 GHz while a WLAN sampling frequency unit  320  provides over-sampling rate of 480 MHz for the use in the D/A converter  222  of  FIG. 2 . During the UWB mode, a MUX unit  330 , which is controlled by using a selectable unit  340 , passes through the UWB sampling frequency unit  310  as the output-sampling rate. During the WLAN mode, the MUX unit  330  passes through the WLAN sampling frequency unit  320  as the output-sampling rate. Thus, the D/A converter  222  operates under controlling the sampling frequency rate either with UWB of 1 GHz or with WLAN of 480 MHz. The software control unit  228  controls the selectable unit  340 . 
   Referring to  FIG. 4  is a detailed block diagram  400  of showing a dual-mode digital lowpass shaping FIR filter system  220  for the UWB and WLAN 802.11a according to some embodiments. During the UWB mode, there is an indoor or outdoor operation. If the indoor operation is used, a switch  430  is connected to a position  420 A and a switch  450  is connected to a position  440 A. Thus, the indoor UWB digital lowpass shaping FIR filter  410  is used for the UWB indoor transmitter. If the outdoor operation is used, the switch  430  is connected to a position  420 B and the switch  450  is connected to a position  440 B. Thus, the outdoor UWB digital lowpass shaping FIR filter  412  is used for the UWB outdoor transmitter. During the WLAN 802.11a mode, the switch  430  is connected to a position  420 C and the switch  450  is connected to a position  440 C. In this case, the WLAN digital multistage lowpass shaping FIR filter  414  is used for the WLAN 802.11a transmitter. Using the software control unit  228  controls both the switches  430  and  450 . 
   Referring to  FIG. 5 , which is a detailed block diagram  500  of showing an embodiment of the WLAN digital multistage lowpass shaping FIR filter  414 . This is a multistage interpolation-shaping filter with upsampling of 24 for the WLAN 802.11a transmitting signal. The input signal is first upsampled by 2 by using an upsampling unit  510 . The output of the upsampling unit  510  is passed through the WLAN digital 12 th  enlarged band lowpass shaping FIR filter  520 . The output of the WLAN digital 12 th  enlarged band lowpass shaping FIR filter  520  is used by upsampling of 12 by using an upsampling unit  530 . Then, the output of the upsampling unit  530  is passed through the WLAN digital rejected lowpass FIR filter  540  as the output. 
   Referring to  FIG. 6  is a detailed block diagram  600  of showing the dual-mode multichannel-based multi-carrier  224  according to some embodiments. The input digital signal is passed through the D/A converter  222  to produce the analog signal for an analog lowpass filter  610  in which reconstructs and smoothes the signal into time-domain signal. The time-domain signal is multiplied  612  by one of the multi-carriers from a MUX unit  614 . Using the software control unit  228  controls the MUX unit  614 . During the UWB mode, a commuter unit  616  can select one of the multi-carriers from selectable multi-carrier frequencies  620  by using a switch  618  that is controlled by using the software control unit  228 . During the WLAN 802.11a mode, the software control unit  228  controls a MUX  622  to select one of the multi-carriers from either a commuter unit  624  or a commuter unit  628  depending on whether the WLAN lower or upper band selectable multi-carrier frequencies is used for transmitter. A switch  626  is used to connect with one of the positions in the commuter unit  624 . A switch  630  is used to connect with one of the positions in the commuter unit  628 . Using the software control unit  228  controls the both switches  626  and  630 . Then, the time-domain signals with multi-carriers are sequentially passed the power amplifier (PA)  226  through an antenna into air. 
     FIG. 7  is an indoor UWB transmitter output of multi-carrier frequency spectrums (dBm)  700  including 11 transmitter channel spectrums  720 A– 720 K along with the indoor FCC emission limitation  710  according to some embodiments. Each channel frequency bandwidth is 650 MHz and is fitted under the indoor FCC emission limitation  710  with different carrier frequencies. The detail positions of each transmitter channel spectrums (dBm) along with the center, lower and upper frequencies (GHz) as well as channel frequency bandwidth (MHz) are listed in Table 3. 
   
     
       
             
             
             
             
             
           
             
             
             
             
             
           
         
             
               TABLE 3 
             
             
                 
             
             
               Label of 
                 
                 
                 
                 
             
             
               transmitter 
             
             
               channel 
               Center 
               Lower 
               Upper 
               Frequency 
             
             
               frequency 
               Frequency 
               Frequency 
               Frequency 
               Bandwidth 
             
             
               spectrums 
               (GHz) 
               (GHz) 
               (GHz) 
               (MHz) 
             
             
                 
             
           
           
             
                 
             
           
        
         
             
               720A 
               3.45 
               3.125 
               3.775 
               650 
             
             
               720B 
               4.10 
               3.775 
               4.425 
               650 
             
             
               720C 
               4.75 
               4.425 
               5.075 
               650 
             
             
               720D 
               5.40 
               5.075 
               5.725 
               650 
             
             
               720E 
               6.05 
               5.725 
               6.375 
               650 
             
             
               720F 
               6.70 
               6.375 
               7.025 
               650 
             
             
               720G 
               7.35 
               7.025 
               7.675 
               650 
             
             
               720H 
               8.00 
               7.675 
               8.325 
               650 
             
             
               720I 
               8.65 
               8.325 
               8.975 
               650 
             
             
               720J 
               9.30 
               8.975 
               9.625 
               650 
             
             
               720K 
               9.95 
               9.625 
               10.275 
               650 
             
             
                 
             
           
        
       
     
   
     FIG. 8  is the outdoor UWB output of multi-carrier frequency spectrums (dBm)  800  including 11 transmitter channel spectrums  820 A– 820 K along with the outdoor FCC emission limitation  810  according to some embodiments. Each channel frequency bandwidth is 650 MHz and is fitted under the outdoor FCC emission limitation  810  with different carrier frequencies. The detail positions of each transmitter channel spectrums (dBm) along with the center, lower and upper frequencies (GHz) as well as channel frequency bandwidth (MHz) are also showed in Table 3, where the label of transmitter channel frequency spectrums are from  820 A, . . .  820 J, and  820 K. 
     FIG. 9  is the WLAN 802.11a output of multi-carrier frequency spectrum (dB)  900  including 8 lower transmitter spectrums  910 A– 910 H and 4 upper transmitter spectrums  920 A– 920 D according to some embodiments. Each channel frequency bandwidth is 20 MHz. The detail positions of each transmitter channel spectrums (dB) along with the center, lower and upper frequencies (GHz) as well as channel frequency bandwidth (MHz) are listed in Table 4. 
   
     
       
             
             
             
             
             
           
         
             
               TABLE 4 
             
             
                 
             
             
               Label of 
                 
                 
                 
                 
             
             
               transmitter 
             
             
               channel 
               Center 
               Lower 
               Upper 
               Frequency 
             
             
               frequency 
               Frequency 
               Frequency 
               Frequency 
               Bandwidth 
             
             
               spectrums 
               (MHz) 
               (MHz) 
               (MHz) 
               (MHz) 
             
             
                 
             
           
           
             
               910A 
               5180 
               5170 
               5190 
               20 
             
             
               910B 
               5200 
               5190 
               5210 
               20 
             
             
               910C 
               5220 
               5210 
               5230 
               20 
             
             
               910D 
               5240 
               5230 
               5250 
               20 
             
             
               910E 
               5260 
               5250 
               5270 
               20 
             
             
               910F 
               5280 
               5270 
               5290 
               20 
             
             
               910G 
               5300 
               5290 
               5310 
               20 
             
             
               910H 
               5320 
               5310 
               5330 
               20 
             
             
               920A 
               5745 
               5735 
               5755 
               20 
             
             
               920B 
               5765 
               5755 
               5775 
               20 
             
             
               920C 
               5785 
               5775 
               5795 
               20 
             
             
               920D 
               5805 
               5795 
               5815 
               20 
             
             
                 
             
           
        
       
     
   
     FIG. 10  is a block diagram of showing a dual-mode UWB WLAN 802.11a communication receiver  1000  according to some embodiments. This dual-mode UWB WLAN 802.11a communication receiver  1000  can deal with the signals either in UWB or in WLAN 802.11a. 
   During the UWB mode, a low noise amplifier (LNA)  1010 , which is coupled to a multichannel-based multi-carrier down converter  1012 , receives the UWB signals from an antenna. The output of LNA  1010  is passed through the multichannel-based multi-carrier down converter  1012  to produce the baseband signal for an A/D converter  1014 , with 6-bit resolution and sampling frequency rate at 1 GHz. The software control unit  228  controls the multichannel-based multi-carrier down converter  1012 , the A/D converter  1014  and a dual-mode digital receiver filter system  1016 . The bandlimited UWB analog signals are then sampled and quantized by using the A/D converter  1014 . The digital signals of the output of the A/D converter  1014  are filtered by using an digital receiver lowpass filter  1016  to remove the out of band signals. A switch  1042 , which is also controlled by using the software control unit  228 , is connected to a position  1040 A. Thus, the output data of the digital receiver lowpass filter  1016  is used for a rake receiver  1020 . The rake receiver  1020  calculates correlation between the received UWB signals and the channel spread sequences and performs coherent combination. The output of the rake receiver  1020  is passed to an equalizer  1022  to eliminate inter-symbol interference (ISI) and inter-channel interference (ICI). A channel estimator  1024  is used to estimate the channel phase and frequency that are passed into the rake receiver  1020  and the equalizer  1022 . Then, the output of the equalizer  1022  produces the signals for a de-spreading of PN sequence and de-mapping  1026  to form the UWB signals of bit rate at 446.875 Mbps. A switch  1046  is connected to a position  1044 A. Thus, the bit data is de-interleaved by using a block de-interleaver  1036 . The output data of the block de-interleaver  1036  is used for the Viterbi decoder  1038  to decode the encoded data and to produce the information data bits at 223.4375 Mbps. 
   During the WLAN 802.11a mode, the low noise amplifier (LNA)  1010 , which is coupled to the multichannel-based multi-carrier down converter  1012 , receives the WLAN 802.111a signals from an antenna. The output of LNA  1010  is passed through the multichannel-based multi-carrier down converter  1012  to produce the baseband signal for the A/D converter  1014 , with 6-bit resolution and sampling frequency rate at 480 MHz. The software control unit  228  controls the multichannel-based multi-carrier down converter  1012 , the A/D converter  1014  and the dual-mode digital receiver filter system  1016 . The bandlimited WLAN 802.11a analog signals are then sampled and quantized by using the A/D converter  1014 . The digital signals of the output of the A/D converter  1014  are filtered by using the digital receiver lowpass filter  1016  to remove the out of band signals. The switch  1042 , which is also controlled by using the software control unit  228 , is connected to a position  1040 B. Thus, the output data of the digital receiver lowpass filter  1016  is used for an I/Q demodulation  1030 . A FFT unit  1032  is used to the output signal of the I/Q demodulation  1030 . The output signal of the FFT unit  1032  is converted from parallel signal into serial signal by using a mapping unit  1034 . The switch  1046  is connected to a position  1044 B. The channel estimator  1024  is used to estimate the channel phase and frequency that are passed for the FFT unit  1032 . Then, the bit data is de-interleaved by using the block de-interleaver  1036 . The output data of the block de-interleaver  1036  is used for the Viterbi decoder  1038  to decode the user-encoded data. 
     FIG. 11  is a block flowchart  1100  of showing the dual-mode UWB and WLAN 802.11a transceiver with transmitter and receiver modes according to some embodiments. A UWB and WLAN 802.11a  1110  is connected with a transmitter and receiver mode  1120 , which is also coupled to a UWB mode  1130 . In the UWB mode, the indoor UWB  1140  is used to determine whether an indoor UWB mode or an outdoor UWB mode should be used. If the indoor UWB mode is selected, the indoor filters  1144  are used. Otherwise, the outdoor filters  1142  are used. Then, a multicarrier  1146  is determined. Thus, a UWB operation  1148  sets for running entire instructions. In the WLAN 802.11a mode, a WLAN lower band unit  1150  is used to determine whether a lower band carrier or an upper band carrier is used. If the lower band carrier is selected, the lower band carrier is used. Otherwise, the upper band carrier is used. Then, a filter system sets for operation. Thus, a WLAN operation  1158  sets for running entire instructions. An end  1160  is used to finish the program. 
   While the present inventions have been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of these present inventions.