| Method and apparatus for controlling a tx power amplifier -> Monitor Keywords |
|
|
  Method and apparatus for controlling a tx power amplifierUSPTO Application #: 20080039033Title: Method and apparatus for controlling a tx power amplifier Abstract: A method and an apparatus for controlling a TX power amplifier are provided in the present invention. The invention is applied for generating a power control curve in a power variation area to control the power variation for signal transmission when the TX power amplifier transmits the data during two continuous time slots, which are a first time slot and a second time slot, respectively have a first transmission power value K1 and a second transmission power value K2. The invention is aimed at producing a concave down inter-ramp control curve in a inter-ramp division of the power variation area for controlling the power variation of the TX power amplifier, where the power for signal transmission is transformed from the first transmission power value K1 to the second transmission power value K2. (end of abstract) Agent: The Law Offices Of Andrew D. Fortney, Ph.d., P.C. - Fresno, CA, US Inventors: Shine C. Huang, Ping-Chun Lin USPTO Applicaton #: 20080039033 - Class: 455127200 (USPTO) Related Patent Categories: Telecommunications, Transmitter, Power Control, Power Supply, Or Bias Voltage Supply, Gain Control The Patent Description & Claims data below is from USPTO Patent Application 20080039033. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This application is a divisional of U.S. patent application Ser. No. 11/047,032, pending, which claims the benefit of Taiwan application Serial No. 93117810, filed Jun. 18, 2004, the subject matter of which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates in general to a method and an apparatus for controlling a TX power amplifier, and more particularly to a method and an apparatus for controlling a TX power amplifier applied in a wireless communication system. [0004] 2. Description of the Related Art [0005] A wireless communication system is used for transmitting data through the air to a remote end. The TX power amplifier (TX PA) amplifies the power of signals in order to prevent signals from being weakened to be indistinguishable noise before the signals reach the target remote end. Generally speaking, the power of the TX PA for signal transmission is increased to a predetermined amplitude before the signal transmission. The process of power increment occurs in a ramp-up division. After the signal transmission, the power of the TX PA for signal transmission is decreased to a minimum amplitude. The process of power decrement occurs in a ramp-down division. [0006] The Time Division Multiple Access (TDMA) system takes one time slot as a unit for transmitting/receiving data. Any two cellular phones will not transmit data in the same time slot (namely, the same time, the same frequency) so as to avoid interferences. Further, the rear portion of a time slot and the front portion of a subsequent times lot are defined as a guard area, and no data transmission occurs in the guard area so as to avoid interferences. Moreover, data for multiple time slots can be continuously transmitted in the TDMA system, and the transmission power for each of the time slots may be varied. When the TDMA system continuously transmits data for multiple time slots, it has to perform the power transformation in the guard area between two continuous time slots. The process of power transformation occurs in an inter-ramp division. [0007] No matter the power amplitudes for two continuous time slots S1 and S2 are progressively increasing, progressively decreasing, or constant, in the TDMA system, the power control curve, representing the power variation of the conventional TX power amplifier for signal transmission, is linear in the ramp-up division, ramp-down division, and inter-ramp division. [0008] Referring to FIGS. 1A to 1C, the timing charts show the variation of power amplitude of a conventional TX power amplifier for signal transmission when continuously transmitting data for two time slots in the TDMA system. As shown in FIG. 1A, the power amplitudes for two continuous time slots S1 and S2 are progressively increased. The inter-ramp control curve IRa is a linear increasing line, and the power amplitudes in the inter-ramp division are greater than the power amplitude of the time slot S1 and less than the power amplitude of the time slot S2. As shown in FIG. 1B, the power amplitudes for two continuous time slots S1 and S2 are progressively decreased. The inter-ramp control curve IRb is a linear decreasing line, and the power amplitudes in the inter-ramp division are less than the power amplitude of the time slot S1 and greater than the power amplitude of the time slot S2. As shown in FIG. 1C, the power amplitudes for two continuous time slots S1 and S2 are constant. The inter-ramp control curve IRc is a horizontal line, and the power amplitudes in the inter-ramp division are the same as the power amplitudes of the time slot S1 and S2. Furthermore, the ramp-up control curve RUa, RUb and RUc are linear increasing lines while the ramp-down control curve RDa, RDb and RDc are linear decreasing lines. [0009] Conventionally, for the ramp-up and ramp-down divisions, the TDMA system has to store the ramp-up control curves and ramp-down control curves corresponding to various power amplitudes in the memory, requiring a large memory space, and applies linear operations for generating inter-ramp control curves for the TX PA. Because the ramp-up control curves and ramp-down control curves are stored in the memory, the conventional approach is able to rapidly generate a power control curve by accessing the memory, but it takes large memory to store a large amount of ramp-up control curves and ramp-down control curves. For the inter-ramp division, because there are many possible combinations of power amplitudes for two continuous time slots, there are too many inter-ramp control curves to store in the memory. Furthermore, in consideration of the operational complexity, the conventional approach generates the inter-ramp control curves for the TX PA by applying simple linear operations. [0010] However, a very large proportion of the power consumption for the whole system is generally resulted from the power consumption of the TX PA. In particular, the larger the signal transmission power is, the larger the power consumption is. In the design of linear connection of two continuous time slots, even though the TX PA does not transmit any data in the inter-ramp division, it still consumes a lot of power. SUMMARY OF THE INVENTION [0011] It is therefore an object of the invention to provide a method and an apparatus for controlling a TX power amplifier. Saving power is achieved by reducing the power amplitude in the guard area. Besides, it requires less memory space for storing and less time for calculating and generating a TX PA power control curve. [0012] The invention achieves the above-identified object by providing a power controlling method, which is applied to a TX power amplifier for controlling power of a signal to-be-transmitted. The method produces a power control curve in a power variation area, having at least one transmission power value K, to control the power variation of the signal. The method includes the following steps. An original curve is first generated according to the transmission power value K, and the original curve is horizontally and equally divided into an original left section FL and an original right section FR. Then, a lowest power value H of the power variation area is determined according to the transmission power value K. A left section ratio SL and a right section ratio SR are determined according to the transmission power value K and the lowest power value H. Besides, a left section FL' of the power control curve is calculated and generated according to the lowest power value H, the original left section FL and the left section ratio SL while a right section FR' of the power control curve is calculated and generated according to the lowest power value H, the original right section FR and the right section ratio SR. Lastly, the power control curve in the power variation area is produced according to the left section FL' and the right section FR' so as to control the power variation of the signal. [0013] The invention achieves the above-identified object by further providing a power controlling apparatus, installed in a wireless communication apparatus, for producing a power control curve in a power variation area, having at least one transmission power value K, to control the power variation of the signal. The apparatus includes a power amplifier and a memory. The power amplifier adjusts power of a signal to-be-transmitted according to the power control curve. The memory includes an original left section table, an original right section table, a lowest power value table, a left section ratio table, and a right section ratio table. The original left section table stores several original left sections, each of which corresponds to one transmission power value. The original right section table stores several original right sections, each of which corresponds to one transmission power value. The lowest power value table stores several lowest power values, each of which corresponds to one transmission power value. The left section ratio table stores several left section ratios, each of which corresponds to one transmission power value and one lowest power value. The right section ratio table stores several right section ratios, each of which corresponds to one transmission power value and one lowest power value. By performing the following, the power control curve is produced. First, an original curve is generated by according to the transmission power value, by searching the original left section table and the original right section table to obtain a corresponding original left section and a corresponding original right section so as to produce the original curve. Then, according to the transmit power value K, the lowest power value table is searched to obtain a corresponding lowest power value H of the power variation area. Next, according to the transmission power value K and the lowest power value H, a left section ratio SL and a right section ratio SR are determined by using the left section ratio table and the right section ratio table. Then, according to the lowest power value H, the original left section FL and the left section ratio SL, a left section FL' of the power control curve is calculated and generated, and according to the lowest power value H, the original right section FR and the right section ratio SR, a right section FR' of the power control curve is calculated. Finally, according to the left section FL' and the right section FR', the power control curve is generated in the power variation area for controlling the power variation of the signal. [0014] Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiment. The following description is made with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIGS. 1A-1C (Prior Art) are timing charts showing the variation of the power amplitude of a conventional TX power amplifier when continuously transmitting data of two time slots in the TDMA system. [0016] FIG. 2 is a timing chart showing the variation of the power amplitude of a TX power amplifier when continuously transmitting data of two time slots according to a preferred embodiment of the invention. [0017] FIG. 3 shows a power controlling method for a TX power amplifier according to a preferred embodiment of the invention. [0018] FIG. 4A shows an original inter-ramp curve according to a preferred embodiment of the invention. [0019] FIG. 4B shows an inter-ramp control curve according to a preferred embodiment of the invention. [0020] FIG. 5A shows an original ramp-up curve according to a preferred embodiment of the invention. [0021] FIG. 5B shows a ramp-up control curve according to a preferred embodiment of the invention. Continue reading... Full patent description for Method and apparatus for controlling a tx power amplifier Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Method and apparatus for controlling a tx power amplifier patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Method and apparatus for controlling a tx power amplifier or other areas of interest. ### Previous Patent Application: Traffic monitoring Next Patent Application: Audio control apparatus, audio system, and navigation apparatus Industry Class: Telecommunications ### FreshPatents.com Support Thank you for viewing the Method and apparatus for controlling a tx power amplifier patent info. IP-related news and info Results in 0.74971 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry |
||
