Abstract:
A dual-mode ultra wideband (UWB) communication transceiver is presented to implement two disparate systems for indoor and outdoor UWB operations. During an operation mode, the dual-mode UWB communication transceiver sends and receives indoor or outdoor UWB signals using indoor or outdoor programmable filters with a multichannel-based multicarrier modulator and downconverter. The dual-mode UWB communication transceiver along with novel transmitter and receiver architectures is able to selectively transmit and receive a very-high data rate with scalability and programmability in an indoor and/or outdoor environment.

Description:
BACKGROUND 
   This invention is generally relative to short-range wireless ultra wideband (UWB) communications for indoor and outdoor operations. 
   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 scarce spectrum resources to be used more efficiently. It has been believed that 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 system 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 devices to imaging systems, vehicular radar systems, and hand held 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 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 Part 15 of the Commission&#39;s rules subject to certain frequency and power limitations. The UWB device must operate in the frequency band from 3.1 GHz to 10.6 GHz. The UWB devices should also satisfy the Part 15.209 limit, which sets emission limits for indoor and outdoor UWB system, for the frequency band below 960 MHz and conform the FCC&#39;s emission masks for the frequency band above 960 MHz. 
   For indoor UWB communication operation, Table 1 lists the FCC 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 
             
             
                 
                 
             
           
        
       
     
   
   Outdoor handheld UWB communication systems are intended to operate in a peer-to-peer mode without restrictions on a location. However, the outdoor handheld UWB communication systems must operate in the frequency band from 3.1 GHz to 10.6 GHz, with an extremely conservative out of band emission masks to address interference with other communication devices. The outdoor handheld UWB communication systems are permitted to emit at or below the Part 15.209 limit in the frequency band below 960 MHz. The emissions above 960 MHz 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 an UWB device as any device where the fractional bandwidth is greater than 0.25 based on the formula as follows: 
                   FB   =     2   ⁢     (         f   H     -     f   L           f   H     +     f   L         )         ,           (   1   )               
where f H  is the upper frequency of the −10 dB emission point and f L  is the lower frequency of the −10 dB emission point. The center frequency of UWB transmission is defined as the average of the upper and lower −10 dB points as follows:
 
   
     
       
         
           
             
               
                 
                   F 
                   C 
                 
                 = 
                 
                   
                     
                       
                         f 
                         H 
                       
                       + 
                       
                         f 
                         L 
                       
                     
                     2 
                   
                   . 
                 
               
             
             
               
                 ( 
                 2 
                 ) 
               
             
           
         
       
     
   
   In addition, a minimum frequency bandwidth of 500 MHz must be used for indoor and outdoor UWB communication devices regardless of the center frequency. 
   The UWB communication devices must be designed to ensure that the indoor operations can only occur in an indoor environment according to the indoor emission masks in Table 1. On the other hand, they must be designed as hand-held UWB devices that may be employed for such activities as peer-to-peer operations according to the outdoor emission masks in Table 2. Such UWB communication devices can be used for wireless communications, particularly for short-range high-speed data transmissions suitable for broadband access to networks. 
   Since the indoor and outdoor UWB communication devices may have similar structures and operation functions, designing a dual-mode UWB communication device with the ability of using in the indoor and outdoor operation is crucial. This leads to save the cost for a dual-mode indoor and outdoor UWB communication transceiver. However, the dual-mode indoor and outdoor UWB communication transceiver needs to have different transmission and receiver filters, which are key elements to make such the UWB communication transceiver successfully. This is because the dual-mode indoor and outdoor UWB communication transceiver has to meet the different masks of the FCC emission limitations for indoor and outdoor operations. 
   Thus, there is a continuing need for the UWB communication transceiver with employing a dual-mode architecture of digital transmission-shaping filters and receiver filters for the indoor and outdoor operations. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a block diagram of one embodiment of a dual-mode UWB communication transceiver for the indoor and outdoor operation in accordance with the present invention. 
       FIG. 2  is a block diagram showing a dual-mode UWB communication transmitter for the indoor and outdoor operation according to some embodiments. 
       FIG. 3  is a transmitter spectrum mark of an indoor power spectrum density (dBm) according to some embodiments. 
       FIG. 4  is a transmitter spectrum mark of an outdoor power spectrum density (dBm) according to some embodiments. 
       FIG. 5  is a block diagram showing one embodiment of a dual-mode digital transmission-shaping filters of the present invention. 
       FIG. 6  is an enlarged transmitter spectrum mark of the indoor power spectrum density (dBm) according to some embodiments. 
       FIG. 7  is a frequency and impulse response of a digital enlarged transmission-shaping filter for the indoor operation according to one embodiment. 
       FIG. 8  is a frequency response of a multiband digital transmitter shaping finite impulse response (FIR) filter for the indoor operation according to one embodiment. 
       FIG. 9  is an enlarged transmitter spectrum mark of the outdoor power spectrum density (dBm) according to some embodiments. 
       FIG. 10  is a frequency and impulse response of the digital enlarged transmission-shaping filter for the outdoor operation according to one embodiment. 
       FIG. 11  is a frequency response of the multiband digital transmitter shaping FIR filter for the outdoor operation according to one embodiment. 
       FIG. 12  is a rejected transmitter image spectrum mark using in both of the indoor and outdoor operations according to some embodiments. 
       FIG. 13  is a frequency and impulse response of a digital rejected transmitter image filter according to one embodiment. 
       FIG. 14  is a frequency response showing a cascaded result of the indoor multiband digital transmitter shaping FIR filter and the digital rejected transmitter image filter according to one embodiment. 
       FIG. 15  is a frequency response showing a cascaded result of the outdoor multiband digital transmitter shaping FIR filter and the digital rejected transmitter image filter according to one embodiment. 
       FIG. 16  is a frequency spectrum including 11 transmitter channel spectrums for the indoor operation along with the indoor FCC emission mask limitation according to some embodiments. 
       FIG. 17  is a frequency spectrum including 11 transmitter channel spectrums for the outdoor operation along with the outdoor FCC emission mask limitation according to some embodiments. 
       FIG. 18  is a block diagram showing a dual-mode architecture of the digital transmitter-shaping FIR filter for the indoor and outdoor operations according to some embodiments. 
       FIG. 19  is a block diagram showing a pre-addition architecture using in the dual-mode digital transmitter-shaping filter with the indoor and outdoor operations according to some embodiments. 
       FIG. 20  is a block diagram showing memory structures that contain transmission filter coefficients and input samples. 
       FIG. 21  is a block diagram showing a dual-mode UWB communication receiver for the indoor and outdoor operations according to some embodiments. 
       FIG. 22  is a block diagram showing one embodiment of dual-mode digital receiver filters of the present invention. 
       FIG. 23  is a receiver spectrum mark of the indoor power spectrum density (dBm) according to some embodiments. 
       FIG. 24  is a frequency and impulse response of an indoor digital receiver filter according to one embodiment. 
       FIG. 25  is a receiver spectrum mark of the outdoor power spectrum density (dBm) according to some embodiments. 
       FIG. 26  is a frequency and impulse response of an outdoor digital receiver filter according to one embodiment. 
       FIG. 27  is a block diagram showing the dual-mode architecture of the digital receiver filter for the indoor and outdoor operation according to some embodiments. 
       FIG. 28  is a block diagram showing a pre-addition architecture using in the dual-mode digital receiver filter according to some embodiments. 
       FIG. 29  is a block diagram showing memory structures that contains the receiver filter coefficients and input samples according to some embodiments. 
       FIG. 30  is a block diagram showing a flowchart implementation of the dual-mode UWB communication transceiver for the indoor and outdoor operations according to some embodiments. 
   

   DETAILED DESCRIPTION 
   Some embodiments described herein are directed to a dual-mode UWB communication transceiver for the indoor and outdoor operations. The dual-mode UWB 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, and/or a combination of hardware and software. 
     FIG. 1  illustrates a dual-mode UWB communication transceiver  100  for the indoor and outdoor operations in accordance with one embodiment of the present invention. This dual-mode UWB communication transceiver  100  includes an indoor or outdoor UWB multi-carrier and multichannel RF section  114  that receives and/or transmits multichannel UWB signals from an antenna  112  or to an antenna  110 . The section  114  is connected with an analog and digital interface section  116  that contains A/D and D/A converters. The interface section  116  is coupled to an indoor and outdoor digital baseband processing section  118 , which performs multichannel digital transmission and receiver filtering, rake processing, spread/de-spread processing, interleave/de-interleave, and code/de-code processing. The digital baseband processing section  118  has an interface with an UWB network interface section  120 , which is coupled to an UWB network  122 . In accordance with one embodiment of the present invention, the UWB communication transceiver  100  is referred to as the dual-mode UWB communication transceiver for the indoor and outdoor operations that can both transmit and receive speech, audio, images and video, and data information for indoor and/or outdoor wireless broadband communications. 
   The dual-mode UWB communication transceiver  100  for the indoor and outdoor operations can transmit and/or receive the UWB signals by using one channel and/or up to 11 channels in parallel. Each channel of the dual-mode UWB communication transceiver  100 , which has a frequency bandwidth of 650 MHz, can transmit a data rate of 40.625 Msps. That is, a total of 11 channels are able to transmit 446.875 Msps. The dual-mode UWB communication transceiver  100  also employs orthogonal spread codes to all of the channels. With 16 pseudorandom noise (PN) spread sequence codes for each symbol, each channel achieves a chip data rate of 650 Mcps. As a result, the dual-mode UWB communication transceiver  100  can transmit and/or receive the chip data rate up to 7.150 Gcps during the indoor and/or outdoor operations. 
     FIG. 2  is a block diagram showing a dual-mode UWB communication transmitter  200  for the indoor and outdoor operations according to some embodiments. The dual-mode UWB communication transmitter  200  receives user data bits  210  with information data rate at 223.4375 Mbps. The user data bits  210  are passed through a ½-rate convolution encoder  212  that may produce a double data rate of 446.875 Msps by adding redundancy bits. A symbol data is then interleaved by using a block interleaver  214 . Thus, the output symbols of the block interleaver  214  are formed 11-multichannel by using a multichannel PN sequence mapping  218 . The symbol data rate of each channel is about 40.625 Msps. The multichannel PN sequence mapping  218  is used to perform spreading for one symbol data with 16 PN orthogonal spread sequence chips. Thus, each channel produces a chip data rate of 650 Mcps under a multichannel control  230 . A PN sequence look-up table  216  provides unique orthogonal sequences to spread each channel. A chip data of each channel is sequentially passed through an indoor or outdoor dual-mode digital FIR lowpass shaping filters  220  to limit each channel signal with a frequency bandwidth of 650 MHz. Each channel signal is passed through a D/A converter  222 . 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 modulator  224 . A clock control  228  is used to control the dual-mode digital FIR lowpass shaping filter  220 , the D/A converter  222 , and the multichannel-based multi-carrier modulator  224 . Thus, the output analog signals of the multichannel-based multi-carrier modulator  224  are passed to a power amplifier (PA)  226  through an antenna into air. 
     FIG. 3  is a transmitter spectrum mark  320  of an indoor power spectral density  300  for each channel according to some embodiments. The magnitudes (dBm) of the frequency response with an error of ±δ i (i=1, 2, 3, 4) according to the frequencies (GHz) are given by,
 (−41.4−δ 1 )≦| H ( f )|≦(−41.4+δ 1 ),| f−f   c |≦0.26,  (3) | H ( f )|≦(−51.8+δ 2 ),| f−f   c |=0.325,  (4) | H ( f )|≦(−54.3+δ 3 ),| f−f   c |=0.39,  (5) | H ( f )|≦(−76.8+δ 4 ),0.45≦| f−f   c |≦0.5.  (6) 
The transmitter spectrum mark  320  serves as a guide to design a digital FIR lowpass-shaping transmitter for the indoor UWB communication transceiver.
 
     FIG. 4  is a transmitter spectrum mark  420  of an outdoor power spectral density  400  using in each channel transmitter filter according to some embodiments. The magnitudes (dBm) of the frequency response with an error of ±δ i (i=1, 2, 3, 4) according to the frequencies (GHz) are given by,
 (−41.8−δ 1 )≦| H ( f )|≦(−41.8+δ 1 ),| f−f   c |≦0.26,  (3) | H ( f )|≦(−61.8+δ 2 ),| f−f   c |=0.325,  (4) | H ( f )|≦(−63.8+δ 3 ),| f−f   c |=0.39,  (5) | H ( f )|≦(−75.8+δ 4 ),0.45≦| f−f   c |≦0.5.  (6) 
The transmitter spectrum mark  420  serves as a guide to design the digital FIR lowpass-shaping transmitter for the outdoor UWB communication transceiver.
 
   A direct design of the indoor and outdoor digital FIR lowpass-shaping transmitter filters based on the indoor transmitter spectrum mask  320  and the outdoor transmitter spectrum mask  420  will lead to a huge number of filter taps. In order to reduce the number of filter taps of the digital FIR lowpass-shaping transmitter filters for the dual-mode UWB communication transmitter  200 , an efficient design method 500 of the cascaded filters may be used as shown in  FIG. 5 . The results of the cascaded filters meet the requirements of the indoor transmitter spectrum mask  320  and the outdoor transmitter spectrum mask  420  while the number of filter taps of the digital FIR lowpass-shaping transmitter filters can be significantly reduced for the indoor and/or outdoor operations. 
   Referring to  FIG. 5  is a block diagram showing a dual-mode digital FIR lowpass-shaping transmitter filter  500  for the indoor and outdoor dual-mode UWB communication transmitter according to some embodiments. During the indoor UWB transmitter mode, a switch  512  is connected to a position  510 A and a switch  520  is connected with a position  518 A. In this case, an indoor UWB enlarged band digital FIR filter  514  is cascaded with an UWB digital rejected FIR filter  522 . The combination of the indoor UWB enlarged band digital FIR filter  514  and the UWB digital rejected FIR filter  522  can achieve an indoor transmitter function that meets the requirement of the transmitter spectrum mask  320  of the indoor power spectrum density  300  as shown in  FIG. 3 . On the other hand, during the outdoor UWB transmitter mode, the switch  512  is connected to a position  510 B and the switch  520  is connected with a position  518 B. In this case, the outdoor UWB enlarged band digital FIR filter  516  is cascaded with the UWB digital rejected FIR filter  522 . The combination of the outdoor UWB enlarged band digital FIR filter  516  and the digital rejected FIR filter  522  can obtain an outdoor transmitter function that meets the requirements of the transmitter spectrum mask  420  of the outdoor power spectrum density  400  as shown in  FIG. 4 . 
   The UWB digital rejected FIR filter  522  as shown in  FIG. 5  contains an even filter with even taps  524 A and an odd filter with odd taps  524 B. The switch  528  is connected with the position  526 A (when n=0, 2, 4, . . . ) and is connected with the position  526 B (when n=1, 3, 5, . . . , respectively. Thus, the even filter  524 A and the odd filter  524 B operate in parallel. This is equivalent to a polyphase implementation structure for an interpolation filter with up sampling by 2. 
   Referring to  FIG. 6 , which is an enlarged transmitter spectrum mark  620  of an indoor power spectral density  600  using for the indoor enlarged digital lowpass shaping FIR filter  514  of  FIG. 5  according to some embodiments. The enlarged transmitter spectrum mark  620  is a double frequency bandwidth of the transmitter spectrum mask  320  of the indoor power spectrum density  300  as shown in  FIG. 3 . The magnitudes (dBm) of the frequency response of the enlarged transmitter filter with an error of ±δ i (i=1, 2, 3, 4) according to the frequencies (GHz) are given by,
 
(−41.8−δ 1 )≦| H ( f )|≦(−41.8+δ 1 ),| f−f   c |≦0.512,  (3)
 
| H ( f )|≦(−51.8+δ 2 ),| f−f   c |=0.65,  (4)
 
| H ( f )|≦(−54.3+δ 3 ),| f−f   c |=0.78,  (5)
 
| H ( f )|≦(−75.8+δ 4 ),0.9≦| f−f   c |≦2.  (6)
 
The enlarged transmitter spectrum mark  620  serves as a guide to design the indoor enlarged digital lowpass-shaping FIR transmitter filter  514  for the indoor UWB communication transmitter.
 
   Referring to  FIG. 7  is a frequency and impulse response  700  of the indoor digital enlarged lowpass-shaping FIR transmitter filter based on the enlarged transmitter spectrum mark  620  according to some embodiments. The impulse response  720  of the indoor digital enlarged lowpass-shaping FIR transmitter filter is an odd symmetric and linear phase with a total of 51 filter coefficients. Table 3 lists all the filter coefficients. 
   
     
       
             
             
             
           
         
             
                 
               TABLE 3 
             
             
                 
                 
             
             
                 
               Coefficients 
               Value 
             
             
                 
                 
             
           
           
             
                 
               h[0] 
                 8.4146443275983984e−005 
             
             
                 
               h[−1],h[1] 
                 6.6538759917782311e−005 
             
             
                 
               h[−2],h[2] 
                 3.4858868895304791e−005 
             
             
                 
               h[−3],h[3] 
                 4.1937291332765197e−006 
             
             
                 
               h[−4],h[4] 
               −1.1315071537226617e−005 
             
             
                 
               h[−5],h[5] 
               −1.1106740829476855e−005 
             
             
                 
               h[−6],h[6] 
               −3.9951396057640505e−006 
             
             
                 
               h[−7],h[7] 
                 1.7898880674583391e−006 
             
             
                 
               h[−8],h[8] 
                 3.8545744226485537e−006 
             
             
                 
               h[−9],h[9] 
                 3.5424465162252467e−006 
             
             
                 
               h[−10],h[10] 
                 2.0127906711873520e−006 
             
             
                 
               h[−11],h[11] 
               −4.4201040083757460e−007 
             
             
                 
               h[−12],h[12] 
               −2.8002950717915257e−006 
             
             
                 
               h[−13],h[13] 
               −3.2214448679624463e−006 
             
             
                 
               h[−14],h[14] 
               −1.0826918814367627e−006 
             
             
                 
               h[−15],h[15] 
                 1.8271797116557857e−006 
             
             
                 
               h[−16],h[16] 
                 2.9338389172971390e−006 
             
             
                 
               h[−17],h[17] 
                 1.4975933707645800e−006 
             
             
                 
               h[−18],h[18] 
               −8.3125861034249542e−007 
             
             
                 
               h[−19],h[19] 
               −1.9498085493385459e−006 
             
             
                 
               h[−20],h[20] 
               −1.3114239806658213e−006 
             
             
                 
               h[−21],h[21] 
                 2.8157753999354317e−008 
             
             
                 
               h[−22],h[22] 
                 8.5150911646371978e−007 
             
             
                 
               h[−23],h[23] 
                 8.4195702592509668e−007 
             
             
                 
               h[−24],h[24] 
                 4.1121891811157223e−007 
             
             
                 
               h[−25],h[25] 
               −1.9624930527271418e−008 
             
             
                 
                 
             
           
        
       
     
   
   The digital enlarged lowpass-shaping FIR transmitter filter  700  may be designed using the least square method with weighting function for each frequency band. Other techniques such as equiripple approximations and windowing may also be used. 
   The implementation output y[n] of the digital enlarged lowpass-shaping FIR transmitter filter with 51 odd symmetric coefficients can be expressed as, 
                     y   ⁡     [   n   ]       =       ∑     k   =   0     50     ⁢       h   ⁡     [   n   ]       ⁢     x   ⁡     [     n   -   k     ]             ,           (   7   )               
where h[n] is a set of the digital enlarged lowpass-shaping FIR transmitter filter coefficients as shown in Table 3 and x[n] is a digital input signal. Since the digital enlarged lowpass-shaping FIR transmitter filter  700  has odd symmetric coefficients, the above equation (7) can be rewritten as
 
                   y   ⁡     [   n   ]       =         ∑     k   =   0     24     ⁢       h   ⁡     [   n   ]       ⁢     (       x   ⁡     [     n   -   k     ]       +     x   ⁡     [     n   -   50   +   k     ]         )         +       h   ⁡     [   25   ]       ⁢       x   ⁡     [     n   -   25     ]       .                 (   8   )               
The equation (8) can be implemented with saving half filter taps for the computation. The computation complexity of implementing this digital enlarged lowpass-shaping FIR transmitter filter  700  in the equation (8) is 25 multiplications and 50 additions.
 
   Referring to  FIG. 8  is a frequency response  810  of the indoor multiband digital lowpass-shaping FIR transmitter filter  800  according to some embodiments. The multi-frequency bands in the FIR transmitter filter  800  are symmetric with the center frequency. This multiband digital lowpass-shaping FIR filter is created by inserting one zero in between every two filter coefficients of the indoor digital enlarged lowpass shaping FIR transmitter filter  720 . This FIR transmitter filter is also referred to as the half-band FIR transmitter filter. Since the zero coefficients do not have computations with input samples, this indoor multiband digital lowpass-shaping FIR transmitter filter has the same as the computation complexities of the digital enlarged lowpass-shaping FIR transmitter filter  700 . Thus, the computation complexity of the indoor multiband digital lowpass-shaping FIR transmitter filter  810  has also 25 multiplications and 50 additions. 
   Referring to  FIG. 9 , which is an enlarged transmitter spectrum mark  920  of the outdoor power spectral density  900  using for the outdoor digital enlarged lowpass-shaping FIR transmitter filter  516  of  FIG. 5  according to some embodiments. The enlarged transmitter spectrum mark  920  is a double frequency bandwidth of the transmitter spectrum mask  420  of the outdoor power spectrum density  400  as shown in  FIG. 4 . The magnitudes (dBm) of the frequency response of the outdoor digital enlarged lowpass-shaping FIR transmitter filter with an error of ±δ i (i=1, 2, 3, 4) according to the frequencies (GHz) are given by,
 
(−41.8−δ 1 )≦| H ( f )|≦(−41.8+δ 1 ),| f−f   c |≦0.512,  (3)
 
| H ( f )|≦(−61.8+δ 2 ),| f−f   c |=0.65,  (4)
 
| H ( f )|≦(−63.8+δ 3 ),| f−f   c |=0.78,  (5)
 
| H ( f )|≦(−75.8+δ 4 ),0.9≦| f−f   c |≦2.  (6)
 
The outdoor enlarged transmitter spectrum mark  920  serves as a guide to design an enlarged digital lowpass-shaping FIR transmitter filter for the outdoor UWB communication transmitter.
 
   Referring to  FIG. 10  is a frequency and impulse response  1000  of the outdoor digital enlarged lowpass-shaping FIR transmitter filter based on the enlarged transmitter spectrum mark  920  according to some embodiments. The impulse response  1020  of the outdoor digital enlarged lowpass-shaping FIR transmitter filter is an odd symmetric and linear phase with a total of 79 filter coefficients. Table 4 lists all the outdoor filter coefficients. 
   
     
       
             
             
             
           
         
             
                 
               TABLE 4 
             
             
                 
                 
             
             
                 
               Coefficients 
               Value 
             
             
                 
                 
             
           
           
             
                 
               h[0] 
                 7.7822588092588666e−005 
             
             
                 
               h[−1],h[1] 
                 6.2706159538768121e−005 
             
             
                 
               h[−2],h[2] 
                 3.8005049828479667e−005 
             
             
                 
               h[−3],h[3] 
                 1.0741444546149776e−005 
             
             
                 
               h[−4],h[4] 
               −7.9100957139480000e−006 
             
             
                 
               h[−5],h[5] 
               −1.3617274449966842e−005 
             
             
                 
               h[−6],h[6] 
               −9.2282250841209486e−006 
             
             
                 
               h[−7],h[7] 
               −1.0206653104093280e−006 
             
             
                 
               h[−8],h[8] 
                 5.3549249436944863e−006 
             
             
                 
               h[−9],h[9] 
                 6.9957089527049026e−006 
             
             
                 
               h[−10],h[10] 
                 4.0766726365610294e−006 
             
             
                 
               h[−11],h[11] 
               −8.5812938269354714e−007 
             
             
                 
               h[−12],h[12] 
               −4.4365447822251048e−006 
             
             
                 
               h[−13],h[13] 
               −4.5122012631596486e−006 
             
             
                 
               h[−14],h[14] 
               −1.5288162010848101e−006 
             
             
                 
               h[−15],h[15] 
                 1.9977031110803787e−006 
             
             
                 
               h[−16],h[16] 
                 3.5384682976304697e−006 
             
             
                 
               h[−17],h[17] 
                 2.4119472792416439e−006 
             
             
                 
               h[−18],h[18] 
               −8.0059122411445323e−008 
             
             
                 
               h[−19],h[19] 
               −1.9997685118910229e−006 
             
             
                 
               h[−20],h[20] 
               −2.2569595576355567e−006 
             
             
                 
               h[−21],h[21] 
               −1.0715363497847361e−006 
             
             
                 
               h[−22],h[22] 
                 5.2554956470109584e−007 
             
             
                 
               h[−23],h[23] 
                 1.5115571787722744e−006 
             
             
                 
               h[−24],h[24] 
                 1.4266179588856210e−006 
             
             
                 
               h[−25],h[25] 
                 4.9809052324633844e−007 
             
             
                 
               h[−26],h[26] 
               −5.9066254728929235e−007 
             
             
                 
               h[−27],h[27] 
               −1.1634171626619683e−006 
             
             
                 
               h[−28],h[28] 
               −9.4184481631453274e−007 
             
             
                 
               h[−29],h[29] 
               −1.7852893130696073e−007 
             
             
                 
               h[−30],h[30] 
                 5.8326059832774108e−007 
             
             
                 
               h[−31],h[31] 
                 8.7972213415469824e−007 
             
             
                 
               h[−32],h[32] 
                 5.9787566708851024e−007 
             
             
                 
               h[−33],h[33] 
               −1.4101683384769071e−010 
             
             
                 
               h[−34],h[34] 
               −5.0807887510975745e−007 
             
             
                 
               h[−35],h[35] 
               −6.2137237941119729e−007 
             
             
                 
               h[−36],h[36] 
               −3.5990788197097831e−007 
             
             
                 
               h[−37],h[37] 
                 5.0087020176186946e−008 
             
             
                 
               h[−38],h[38] 
                 3.0946891600984111e−007 
             
             
                 
               h[−39],h[39] 
                 3.3329123246466921e−007 
             
             
                 
                 
             
           
        
       
     
   
   Referring to  FIG. 11  is a frequency response  1110  of the outdoor multiband digital lowpass-shaping FIR transmitter filter  1100  according to some embodiments. The multi-frequency bands of the FIR transmitter filter  1100  are symmetric with the center frequency. This multiband digital lowpass-shaping FIR transmitter filter  1110  is created by inserting one zero in between every two filter coefficients of the outdoor digital enlarged lowpass-shaping FIR transmitter filter  1020 . This multiband digital lowpass-shaping FIR transmitter filter  1110  is also referred to as a half-band digital lowpass-shaping FIR transmitter filter. Since the zero coefficients do not have computations with input samples, this outdoor multiband digital lowpass-shaping FIR transmitter filter  1110  has the same as the computation complexities of the digital enlarged lowpass-shaping FIR transmitter filter  1000 . Thus, the computation complexity of the outdoor multiband digital lowpass-shaping FIR transmitter filter  1100  has 39 multiplications and 78 additions. 
     FIG. 12  is a rejected transmitter image spectrum mark  1220  of a power spectral density  1200  using to eliminate the image bands of the indoor and outdoor digital multiband lowpass-shaping FIR transmitter filters  810  and  1110  according to some embodiments. The magnitudes (dBm) of the frequency response of the rejected transmitter image spectrum mask  1220  with an error of ±δ i (i=1,2) according to the frequencies (GHz) are given by,
 (30.0−δ 1 )≦| H ( f )|≦(30+δ 1 ),| f−f   c ≦0.28,  (3) | H ( f )|≦(−18.3+δ 2 ),1.64≦| f−f   c |≦2.  (6) 
The rejected transmitter image spectrum mark  1200  serves as a guide to design the UWB digital rejected filter  522  as shown in  FIG. 5 .
 
   Referring to  FIG. 13  is a frequency and impulse response of digital rejected lowpass FIR transmitter filter  1300  based on the rejected transmitter image spectrum mask  1220  according to some embodiments. The impulse response  1320  of the digital rejected lowpass FIR transmitter filter has an even symmetric coefficients and linear phase with a total of 6 filter coefficients. The computation complexity of this digital rejected lowpass FIR transmitter filter is 3 multiplications and 5 additions. Table 5 lists all of the digital rejected lowpass FIR transmitter filter coefficients. 
   
     
       
             
             
             
           
         
             
                 
                 
             
             
                 
               Coefficients 
               Value 
             
             
                 
                 
             
           
           
             
                 
               h[−1],h[1] 
                 4.3847963307982163e−001 
             
             
                 
               h[−2],h[2] 
                 1.0531756617949097e−001 
             
             
                 
               h[−3],h[3] 
               −3.7781557560682605e−002 
             
             
                 
                 
             
           
        
       
     
   
   Referring to  FIG. 14  is a frequency response of an indoor combination digital FIR transmitter filter  1410  by cascading the indoor digital enlarged lowpass-shaping FIR transmitter filter  810  and the digital rejected lowpass FIR transmitter filter  1310 . The result of this combination digital FIR transmitter filter  1410  exactly meets the requirement of the transmitter spectrum mask  320  of the indoor power spectrum density  300  in  FIG. 3 . 
   Referring to  FIG. 15  is a frequency response of the outdoor combination digital FIR transmitter filter  1510  by cascading the outdoor digital enlarged lowpass-shaping FIR transmitter filter  1110  and the digital rejected lowpass FIR transmitter filter  1310 . The result of this outdoor combination digital FIR transmitter filter  1510  exactly meets the requirements of the transmitter spectrum mask  420  of the outdoor power spectrum density  400  in  FIG. 4 . 
     FIG. 16  is an indoor output of multi-carrier frequency spectrums (dBm)  1600  including 11 transmitter channel spectrums  1620 A– 1620 K along with the indoor FCC emission limitation  1610  according to some embodiments. Each channel frequency bandwidth is 650 MHz and is fitted under the indoor FCC emission limitation  1610  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 bandwidths (MHz) are listed in Table 6. 
   
     
       
             
             
             
             
             
           
         
             
               TABLE 6 
             
             
                 
             
             
               Label of 
               Center 
               Lower 
               Upper 
               Frequency 
             
             
               transmitter channel 
               Frequency 
               Frequency 
               Frequency 
               Bandwidth 
             
             
               frequency spectrums 
               (GHz) 
               (GHz) 
               (GHz) 
               (MHz) 
             
             
                 
             
           
           
             
               1620A 
               3.45 
               3.125 
               3.775 
               650 
             
             
               1620B 
               4.10 
               3.775 
               4.425 
               650 
             
             
               1620C 
               4.75 
               4.425 
               5.075 
               650 
             
             
               1620D 
               5.40 
               5.075 
               5.725 
               650 
             
             
               1620E 
               6.05 
               5.725 
               6.375 
               650 
             
             
               1620F 
               6.70 
               6.375 
               7.025 
               650 
             
             
               1620G 
               7.35 
               7.025 
               7.675 
               650 
             
             
               1620H 
               8.00 
               7.675 
               8.325 
               650 
             
             
               1620I 
               8.65 
               8.325 
               8.975 
               650 
             
             
               1620J 
               9.30 
               8.975 
               9.625 
               650 
             
             
               1620K 
               9.95 
               9.625 
               10.275  
               650 
             
             
                 
             
           
        
       
     
   
     FIG. 17  is an outdoor output of multi-carrier frequency spectrums (dBm)  1700  including 11 transmitter channel spectrums  1720 A– 1720 K along with the outdoor FCC emission limitation  1610  according to some embodiments. Each channel frequency bandwidth is 650 MHz and is fitted under the outdoor FCC emission limitation  1610  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 bandwidths (MHz) are the same as values listed in Table 6. 
     FIG. 18  is a block diagram showing the dual-mode architecture of the digital lowpass-shaping FIR transmitter filters for indoor and outdoor operations according to some embodiments. Six different memory banks  1812 ,  1814 ,  1816 ,  1830 ,  1834 A and  1834 B are used. Four memory banks  1814 ,  1816 ,  1834 A and  1834 B, which may be Read-Only-Memory (ROM) for single-purpose filters or Random-Access-Memory (RAM) for programmable filters, are dedicated to the filter coefficients that are fixed in values during the indoor and/or outdoor operations. The memory bank  1814  contains the indoor digital enlarged lowpass-shaping FIR transmitter filter coefficients  720 . The memory bank  1816  includes the outdoor digital enlarged lowpass-shaping FIR transmitter filter coefficients  1020 . The memory banks  1834 A and  1834 B store even and odd filter coefficients of the digital rejected lowpass FIR transmitter filter  1320 , respectively. The other memory banks  1812  and  1830  are data memory such as RAM to set aside for the input samples. The data memory banks  1812  and  1830  act as a circular buffer operation. 
   The input samples are passed through a pre-addition  1824  to perform a symmetric addition operation. The output samples of the pre-addition  1824  are stored into the data memory bank  1812  with a circular buffer operation by controlling of a circular counter  1810 . A selectable unit  1822  controls a multiplexer (MUX) unit  1820  to select either the memory bank  1814  or the memory bank  1816  with a counter modular  1818 . The selected memory bank, either the memory bank  1814  or the memory bank  1816 , operates with the input samples in the data memory bank  1812  by using a multiply and accumulate (MAC) unit  1826  to produce the filter output y[n]. Then the output samples y[n] are stored into the data memory bank  1830 . A switch  1840  connects to the position  1838 A when n=0, 2, 4, . . . , and connects to the position  1838 B when n=1, 3, 5, . . . . Thus, the input samples of the data memory bank  1830  with a circular counter  1832  are multiplied and accumulated with the memory banks  1834 A and  1834 B of the even and odd digital rejected FIR transmitter filter coefficients with a counter modular  1836  to produce the output by using a MAC unit  1828 . 
   Referring to  FIG. 19 , which is a detailed block diagram  1900  showing one embodiment of the pre-addition unit  1824  of the present invention. The units  1910 A– 1910 Y and units  1920 A– 1920 Y are called one sample delay unit. There are a total of 50 sample delay units. The units  1930 A– 1930 Y are referred to as an addition operation unit. There are a total of 25 addition operation units. The input samples x[n] are passed through the delay and addition operation units to produce output samples as follows:
 
 q[n−k]=x[n−k]+x[n− 50+ k ], for k=0, 1, 2, . . . , 24.
 
 q[n−k]=x[n−k ], for k=25.
 
Then, a switch  1950  sequentially connects to the positions  1940 A– 1940 Y until the last sample is finished. Thus, the pre-addition unit  1900  may achieve a pre-addition calculation for the input samples that are used to reduce computations when the output samples q[n] are multiplied with the odd symmetric filter coefficients.
 
   Referring to  FIG. 20 , which is a detailed block diagram  2000  showing the filter coefficient memory banks and the data memory banks. The memory banks  1814  and  1816  contain the indoor digital enlarged lowpass-shaping FIR transmitter filter coefficients  720  and the outdoor digital enlarged lowpass-shaping FIR transmitter filter coefficients  1020 , with a counter modular. The data memory bank  1812  contains the input data samples, with the circular counter. The memory banks  1834 A and  1834 B include the even and odd filter coefficients of the digital rejected FIR transmitter filter  1320 , with the counter modular. The data memory bank  1830  contains the input data samples, with the circular counter. 
     FIG. 21  is a block diagram of a dual-mode UWB communication receiver  2100  for the indoor and outdoor operations according to some embodiments. A low noise amplifier (LNA)  2160 , which is coupled to a multichannel-based multi-carrier down converter  2162 , receives the UWB signals from an antenna. The output of the LNA  2160  is passed through the multichannel-based multi-carrier down converter  2162  to produce a baseband signal for an A/D converter  2164 . A multichannel control  2170  and a synchronization and time control  2168  restrain the multichannel-based multi-carrier down converter  2162 . B and limited UWB analog signals are then sampled and quantized by using the A/D converter  2164 , with a sampling rate of 720 MHz. The digital output signals of the A/D converter  2164  are filtered by using an indoor or outdoor dual-mode digital lowpass FIR receiver filter  2166  to remove the out of band signals under controlling from the synchronization and time control  2168 . The output signal of the indoor and outdoor dual-mode digital lowpass FIR receiver filter  2166  is used for a rake receiver  2174 . A channel estimator  2172  is used to estimate a channel phase and frequency that are passed into the rake receiver  2174 . The rake receiver  2174  calculates a correlation between received UWB signals and channel spread sequences, which are provided by using a PN sequence look-up table  2182 , and performs a coherent combination. The output signal of the rake receiver  2174  is passed to an equalizer  2176 , which also receives information from the channel estimator  2172 , to eliminate inter-symbol interference (ISI) and inter-channel interference (ICI). Then, the output signal of the equalizer  2176  produces the signals, which are despreaded and demapped by using a de-spreading of PN sequence and de-mapping  2178 , to form UWB signals with a symbol rate at 446.875 Msps. The UWB signals are then de-interleaved by using a block de-interleaver  2180 . Thus, the output signal of the block de-interleaver  2180  is used for a Viterbi decoder  2184  to decode encoded data and to produce a data rate at 223.4375 Mbps. 
   Referring to  FIG. 22 , which is a detailed block diagram  2200  showing one embodiment of the indoor and outdoor dual-mode digital lowpass FIR receiver filter  2166  of the present invention. During the indoor UWB receiver mode, a switch  2212  connects to a position  2210 A and a switch  2220  connects to a position  2218 A. In this case, the dual-mode digital lowpass FIR receiver filter is used for the indoor UWB communication receiver. During the outdoor UWB receiver mode, the switch  2212  connects to a position  2210 B and the switch  2220  connects to a position  2218 B. Thus, in this case, the dual-mode digital lowpass FIR receiver filter is used for the outdoor UWB communication receiver. 
     FIG. 23  is a receiver spectrum mask  2320  of an indoor UWB power spectrum density  2300  according to some embodiments. The magnitudes (dBm) of the frequency response with an error of ±δ i (i=1, 2, 3) according to the frequencies (MHz) are given by,
 (−41.3−δ 1 )≦| H ( f )|≦(−41.3+δ 1 ),| f−f   c |≦260,  (3) | H ( f )|≦(−51.3+δ 2 ),| f−f   c |=325,  (4) | H ( f )|≦(−75.3+δ 3 ),340≦| f−f   c |≦360.  (6) 
The indoor receiver spectrum mark  2320  serves as a guide to design a digital lowpass FIR receiver filter for the indoor UWB communication receiver.
 
   Referring to  FIG. 24  is a frequency and impulse response  2400  of the indoor digital lowpass FIR receiver filter according to some embodiments. The impulse response  2420  of the indoor digital lowpass FIR receiver filter has an odd symmetric and linear phase with a total of 39 filter coefficients. Thus, the computation complexity of the indoor digital lowpass FIR receiver filter  2420  has 19 multiplications and 38 additions. Table 7 lists all of the indoor digital lowpass FIR receiver filter coefficients. 
   
     
       
             
             
             
           
         
             
                 
               TABLE 7 
             
             
                 
                 
             
             
                 
               Coefficients 
               Value 
             
             
                 
                 
             
           
           
             
                 
               h[0] 
                 2.2711340594043999e−004 
             
             
                 
               h[−1],h[1] 
                 4.2079839082892464e−005 
             
             
                 
               h[−2],h[2] 
               −3.3790355985451722e−005 
             
             
                 
               h[−3],h[3] 
                 2.2800600739704647e−005 
             
             
                 
               h[−4],h[4] 
               −1.2124392687415319e−005 
             
             
                 
               h[−5],h[5] 
                 4.2180879116521021e−006 
             
             
                 
               h[−6],h[6] 
               −1.1365258519547985e−007 
             
             
                 
               h[−7],h[7] 
               −6.3388913197064538e−007 
             
             
                 
               h[−8],h[8] 
               −4.7720212586639754e−007 
             
             
                 
               h[−9],h[9] 
                 1.8041014288773825e−006 
             
             
                 
               h[−10],h[10] 
               −2.2153543980269178e−006 
             
             
                 
               h[−11],h[11] 
                 1.4968638128566580e−006 
             
             
                 
               h[−12],h[12] 
               −1.1830181905096312e−007 
             
             
                 
               h[−13],h[13] 
               −1.1477807925811817e−006 
             
             
                 
               h[−14],h[14] 
                 1.7805637473547527e−006 
             
             
                 
               h[−15],h[15] 
               −1.6754436913295128e−006 
             
             
                 
               h[−16],h[16] 
                 1.1620898376791844e−006 
             
             
                 
               h[−17],h[17] 
               −6.5665355826769077e−007 
             
             
                 
               h[−18],h[18] 
                 4.6288213011845176e−007 
             
             
                 
               h[−19],h[19] 
               −5.6171814558031744e−007 
             
             
                 
                 
             
           
        
       
     
   
     FIG. 25  is a receiver spectrum mask  2520  of an outdoor UWB power spectrum density  2500  according to some embodiments. The magnitudes (dBm) of the frequency response with an error of ±δ i (i=1, 2, 3) according to the frequencies (MHz) are given by,
 (−41.3−δ 1 )≦| H ( f )|≦(−41.3+δ 1 ),| f−f   c |≦260,  (3) | H ( f )|≦(−61.3+δ 2 ),| f−f   c |=325,  (4) | H ( f )|≦(−75.3+δ 3 ),340≦| f−f   c |≦360.  (5) 
The outdoor receiver spectrum mark  2520  serves as a guide to design a digital lowpass FIR receiver filter for the outdoor UWB communication receiver.
 
   Referring to  FIG. 26  is a frequency and impulse response  2600  of the outdoor digital lowpass FIR receiver filter according to some embodiments. The impulse response  2620  of the outdoor digital lowpass FIR receiver filter has odd symmetric filter coefficients and is a linear phase with a total of 39 filter coefficients. Thus, the computation complexity of the outdoor digital lowpass FIR receiver filter  2620  has 19 multiplications and 38 additions. Table 8 lists all of the outdoor digital lowpass FIR receiver filter coefficients. 
   
     
       
             
             
             
           
         
             
                 
               TABLE 8 
             
             
                 
                 
             
             
                 
               Coefficients 
               Value 
             
             
                 
                 
             
           
           
             
                 
               h[0] 
                 2.1659294012222948e−004 
             
             
                 
               h[−1],h[1] 
                 5.1010900807138207e−005 
             
             
                 
               h[−2],h[2] 
               −3.8577600935448179e−005 
             
             
                 
               h[−3],h[3] 
                 2.2434916624067460e−005 
             
             
                 
               h[−4],h[4] 
               −7.4313753473442792e−006 
             
             
                 
               h[−5],h[5] 
               −2.6722025657057541e−006 
             
             
                 
               h[−6],h[6] 
                 6.5007896593555187e−006 
             
             
                 
               h[−7],h[7] 
               −5.1746497965425773e−006 
             
             
                 
               h[−8],h[8] 
                 1.3955837238699170e−006 
             
             
                 
               h[−9],h[9] 
                 2.0273922562789145e−006 
             
             
                 
               h[−10],h[10] 
               −3.3766314744991133e−006 
             
             
                 
               h[−11],h[11] 
                 2.5193334120019112e−006 
             
             
                 
               h[−12],h[12] 
               −5.1162314715269453e−007 
             
             
                 
               h[−13],h[13] 
               −1.2437956638809358e−006 
             
             
                 
               h[−14],h[14] 
                 1.8528143860654983e−006 
             
             
                 
               h[−15],h[15] 
               −1.2782534000936749e−006 
             
             
                 
               h[−16],h[16] 
                 1.7904952933954231e−007 
             
             
                 
               h[−17],h[17] 
                 6.4369115613109251e−007 
             
             
                 
               h[−18],h[18] 
               −7.2838193152203750e−007 
             
             
                 
               h[−19],h[19] 
                 1.7807071893959747e−007 
             
             
                 
                 
             
           
        
       
     
   
     FIG. 27  is a block diagram showing the dual-mode architecture of the digital lowpass FIR receiver filter for the indoor and outdoor operations according to some embodiments. Three different memory banks  2712 ,  2714  and  2716  are used. Two memory banks  2714  and  2716 , which may be ROM for single-purpose filters or RAM for programmable filters, are dedicated to the filter coefficients that are fixed in values during indoor and outdoor operation. The memory bank  2714  contains the indoor digital lowpass FIR receiver filter coefficients  2420 . The memory bank  2716  includes the outdoor digital lowpass FIR receiver filter coefficients  2620 . The other memory bank  2712  is data memory such as RAM to set aside for the input samples. The data memory bank  2712  act as the circular buffer. 
   The input samples are passed through a pre-addition unit  2724  to perform the symmetric addition operation. The output samples of the pre-addition  2724  are stored into the data memory bank  2712  with the circular buffer by controlling a circular counter  2710 . A selectable unit  2722  controls a MUX unit  2720  to select either the memory bank  2714  or the memory bank  2716  with a counter modular  2718 . A selected memory bank, either the memory bank  2714  or the memory bank  2716 , operates with the input samples in the data memory bank  2712  by using a MAC unit  2726  to produce the filter output. 
   Referring to  FIG. 28 , which is a detailed block diagram  2800  showing one embodiment of the pre-addition unit  2724  of the present invention. The units  2810 A– 2810 T and units  2820 A– 2820 T are called one sample delay unit. There are a total of 38 sample delay units. The units  2830 A– 2830 T are referred to as the addition operation unit. There are a total of 19 addition operation units. The input samples x[n] are passed through the delay and addition operation units to produce the output samples as follows:
 
 q[n−k]=x[n−k]+x[n− 50+ k ], for k=0, 1, 2, . . . , 18.
 
 q[n−k]=x[n−k ], for k=19.
 
Then, a switch  2850  sequentially connects to positions  2840 A– 2840 T until the last sample is finished. Thus, the pre-addition unit  2800  may achieve the pre-addition calculation for the input samples that are used to reduce computations when the output samples q[n] are multiplied with the odd symmetric filter coefficients.
 
   Referring to  FIG. 29 , which is a detailed block diagram  2900  showing the filter coefficient memory banks and the data memory banks. The memory banks  2714  and  2716  contain the indoor digital lowpass FIR receiver filter coefficients  2420  and the outdoor digital lowpass FIR receiver filter coefficients  2620 , with the counter modular. The data memory bank  2712  contains the input data samples, with the circular counter. 
     FIG. 30  is a block flowchart showing a dual-mode indoor and outdoor UWB communication transceiver with transmitter and receiver modes according to some embodiments. An indoor and outdoor UWB  3010  is connected with a transmitter or a receiver mode  3012 , which is also coupled to an indoor UWB  3014 . The indoor UWB  3014  is used to determine whether the indoor mode or the outdoor mode should be used. If the indoor mode is selected, indoor filters are used. Otherwise, outdoor filters are used. Then, the UWB communication transceiver is into an UWB operation. An end  3020  is to finish a program. 
   While the present invention has 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 the present invention.