Abstract:
A Customer-Premises Equipment (CPE) device includes a power supply for generating a first power at a first voltage level; a rechargeable battery for generating a second power at a second voltage level; and a power amplifier coupled to the power supply and the rechargeable battery for receiving the first power and the second power to output a third power at a third voltage level higher than either the first voltage level or the second voltage level, wherein the third power is utilized to transmit signals from the CPE device to a BTS.

Description:
CROSS REFERENCE 
       [0001]    The present application claims the benefits of U.S. Provisional Patent Application Ser. No. 60/853,956, which was filed on Oct. 24, 2006 and entitled “Uplink Transmit Power Management for Rechargeable Battery Facilitated Mobile Station.” 
     
     BACKGROUND 
       [0002]    The present invention relates generally to wireless communication networks, and more particularly to rechargeable battery facilitated customer-premises equipment (CPE) for improving uplink transmission power management. 
         [0003]    A typical wireless communication network is comprised of at least one base transceiver station (BTS) that transmits and receives signals to and from one or more CPE devices via wireless links. The BTS is designed to carry out functions, such as signal transmission/reception and channel resource allocation. The CPE device generally refers to any electronic apparatus located in a user&#39;s premise for connecting to the BTS via wireless channels within a wireless communication network. Examples of CPE include telephones, DSL (Digital Subscriber Line) modems, cable modems, cellular phones, set-top boxes and routers. 
         [0004]      FIG. 1  illustrates a conventional CPE device  100  that is connected to a BTS  150  via uplink channels. The CPE device  100  is connected to a power supply  102  for receiving power at a voltage level Pin. The power supply  102  can be, for example, a regular DC power line of an AC adaptor, a universal serial bus (USB) cable, and a battery that outputs relatively constant voltage. The power supply  102  provides the CPE device  100  with power Pin, such that a transmitter  104  implemented within the CPE device  100  can transmit signals to the BTS  150  at power level Pul via uplink channels. In some cases, the power level Pul required for the transmitter  104  to transmit uplink signals to the BST exceeds the power level Pin from the power supply  102 , thereby resulting in low quality or failure of communications. 
         [0005]    As such, what is needed is a CPE device that is able to transmit uplink signals with sufficient power to ensure quality and reliability of signal transmission in a wireless communication network. 
       SUMMARY 
       [0006]    The present invention discloses a CPE device that includes a power supply for generating a first power at a first voltage level; a rechargeable battery for generating a second power at a second voltage level; and a power amplifier coupled to the power supply and the rechargeable battery for receiving the first power and the second power to output a third power at a third voltage level higher than either the first voltage level or the second voltage level, wherein the third power is utilized to transmit signals from the CPE device to a BTS. 
         [0007]    The construction and method of operation of the invention, however, together with additional objectives and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  illustrates a functional block diagram showing a conventional CPE device connected to a BTS via uplink channels. 
           [0009]      FIG. 2  illustrates a functional block diagram showing a proposed CPE device connected to a BTS via uplink channels in accordance with one embodiment of the present invention. 
       
    
    
     DESCRIPTION 
       [0010]    This invention describes a rechargeable battery facilitated CPE device for improving uplink transmission power management in a wireless communication network. The following merely illustrates various embodiments of the present invention for purposes of explaining the principles thereof. It is understood that those skilled in the art will be able to devise various equivalents that, although not explicitly described herein, embody the principles of this invention. 
         [0011]      FIG. 2  illustrates a functional block diagram showing a proposed CPE device  200  connected to a BTS  250  via uplink channels in a wireless communication network, such as a cellular network, a wireless local area network (WLAN), a wireless personal area network (WPAN), and a sensor network, in accordance with one embodiment of the present invention. The wireless communication network can be implemented based on technology such as time division multiple access (TDMA), frequency division multiple access (FDMA), code division multiple access (CDMA), wave division multiple access (WDMA) and orthogonal frequency division multiple access (OFDMA). The CPE device  200  is comprised of at least one transmitter  202  coupled to an antenna  204 , a power supply  210 , a rechargeable battery  206  and a power level detector  208 . The transmitter  202  is implemented with a power amplifier  212  coupled to the power supply  210  and the rechargeable battery  206 , which is further coupled to the power level detector  208 . 
         [0012]    When the CPE device  200  is transmitting signals to the BTS  250  via uplink channels, the power amplifier  212  receives powers from the power supply  210  and the rechargeable battery  206  for the transmitter  202  to transmit signal at a certain power level via the antenna  204 . The power supply  210  can be, for example, a DC power line of an adaptor, a USB cable, or a battery that is able to generate electric power at a relatively constant voltage level Pin as opposed to the voltage level Pb generated by the rechargeable battery  206 . The power amplifier  212  receives Pin from the power supply  210  and Pb from the rechargeable battery  206 , and provides the transmitter  202  with uplink transmission power Pul that exceeds Pin or Pb. In this embodiment, the power amplifier  212  adds the power Pb generated by the rechargeable battery  206  to the power Pin generated by the power supply  210  to provide the uplink transmission power Pul. As a result, the uplink transmission power Pul is substantially equal to the summation of Pin and Pb. As such, the addition of the rechargeable battery  206  increases the power level of the uplink transmission power Pul, which, in turn, improves the signal reception quality at the BTS  250 . 
         [0013]    The rechargeable battery  206  needs to be recharged once in a while, because its reserved power is consumed over time as the CPE device  200  operates. There are several schemes can be used to charge the rechargeable battery  210 . For example, the rechargeable battery  206  can be charged using the power generated by the power supply  210  when no signal is transmitted from the CPE device  200  to the BTS  250 , and terminates the charging when the CPE device  200  is sending out uplink signals. In another example, the rechargeable battery  206  is constantly charged as long as the CPE device  200  receives power from the power supply  210 . 
         [0014]    The BTS  250  allocates channel resources, such as bandwidth and downlink transmission power for each channel, based on the information provided by the voltage level Pul of the uplink transmission signal, which may vary over time depending on the charging state of the rechargeable battery  206 . In order to properly allocate channel resources, the BTS  250  needs to have information regarding the variation of the voltage level Pb indicating the charging state of the rechargeable battery  206 . In this embodiment, the power level detector  208  detects voltage level Pb, and provides the transmitter  202  with a feedback signal indicating the detected voltage level Pb. The transmitter  202  then transmits the feedback signal to the BTS  250  via the antenna  204 , so that it can obtain information regarding the charging state of the rechargeable battery  210  and adjust channel resources for the CPE  200  accordingly. It is understood by people skilled in the art of telecommunications and integrated circuit industry that the power level detector  208  can be readily implemented without undue experiment of any kind. For example, the power level detector can a digital signal processor that is capable of receiving voltage inputs from the rechargeable battery  206 , and generating outputs indicating the voltage level of the inputs. 
         [0015]    Alternatively, the BTS  250  can obtain information regarding the voltage level Pb based on prediction and modeling of the charging state of the rechargeable battery  206 . For example, the transmitter  202  transmits an initial value of the voltage level Pb and the voltage level Pin to the BTS  250 , and the BTS  250  predicts the uplink transmission power level Pul based on Pin and the initial value of Pb adjusted by modeling the charging state of the rechargeable battery  206 . In such case, no feedback signal indicating the actual voltage level Pb will be needed from the CPE device  200 . 
         [0016]    One advantage of the proposed rechargeable battery enhanced CPE device is the improvement in power management. The additional rechargeable battery increases the voltage level of the uplink transmission power, thereby improving the quality of signal reception at the BTS. Moreover, multiple schemes are proposed for the BTS to obtain information regarding the charging state of the rechargeable battery, thereby improving channel resource allocations. 
         [0017]    The above illustration provides many different embodiments or embodiments for implementing different features of the invention. Specific embodiments of components and processes are described to help clarify the invention. These are, of course, merely embodiments and are not intended to limit the invention from that described in the claims. 
         [0018]    Although the invention is illustrated and described herein as embodied in one or more specific examples, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention, as set forth in the following claims.