JP2010232986A - Cellular phone terminal, and integrated circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a measurement time by simplifying measurement of an adjustment value used for obtaining reception electric field strength, in a cellular phone terminal using a low-noise amplifier having a plurality of gain modes. <P>SOLUTION: The low-noise amplifier (LNA) 220 amplifies an RF signal received from a base station selectively in one of a plurality of gain modes. The cellular phone terminal includes, in an RF-IC including the LNA, a memory 224 which stores gain differences among the plurality of gain modes. The cellular phone terminal further includes an adjustment value table for storing, as an adjustment value, the amplification degree of an automatically-variable-gain amplifier capable of providing a predetermined demodulation output level to a reference RF signal of power equivalent to a known reception level. Reception electric field strength is obtained by referring to the adjustment table in accordance with the amplification degree of the automatically-variable-gain amplifier in receiving an actual RF signal, and the obtained reception electric field strength is reported to the base station. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mobile phone terminal using a low-noise amplifier having a plurality of gain modes and an integrated circuit incorporated therein.

  In the mobile phone terminal, since it is necessary to report the electric field level (reception electric field strength) of the radio wave generated from the base station to the base station, individual adjustment regarding received power is performed. The individual adjustment is to write a unique adjustment value table for each mobile phone terminal and to obtain the electric field level with reference to the adjustment value written in the adjustment value table for each terminal.

  Also, a W-CDMA wireless receiver using an LNA gain control method using a low noise amplifier (LNA) having a high gain mode and a low gain mode is known (Patent Document 1). This document describes that a gain difference between a high gain mode and a low gain mode is acquired and stored in a storage device.

JP 2004-208175 A

  In order to create the adjustment value table for individual adjustment described above, it is necessary to perform a reference RF signal measurement operation at the time of shipment for each terminal. In the case where multiple bands of LNA are included, this measurement needs to be performed for each band (in some cases, multiple channels within the band), and in addition, when each LNA has multiple gain modes. Will further increase the time required for measurement.

  In Patent Document 1, the gain difference between the high gain mode and the low gain mode is used to drive the control voltage of the intermediate frequency gain control amplifier (IFGCA) to the optimum setting at high speed. Are not directly related.

  The present invention has been made in such a background, and in a cellular phone terminal using a low-noise amplifier having a plurality of gain modes, the measurement of the adjustment value used for obtaining the received electric field strength is simplified and the measurement time is shortened. Contemplate to do.

  A cellular phone terminal according to the present invention provides a gain difference between a low noise amplifier that selectively amplifies an RF signal received from a base station in one of a plurality of gain modes, and a plurality of gain modes of the low noise amplifier. A stored memory, an automatic variable gain amplifier that receives the output of the low noise amplifier, and an amplification factor of the automatic variable gain amplifier that provides a predetermined demodulated output level with respect to a reference RF signal having a power corresponding to a known reception level And an adjustment value table that stores the received electric field strength by referring to the adjustment value table according to the amplification degree of the automatic variable gain amplifier when an actual RF signal is received. The received field strength is reported to the base station.

  The gain difference stored in the memory may be used before shipment of the mobile phone terminal or may be used after collection. When used before shipment, the result is reflected in the adjustment value table. When used after shipment, it comprises means for obtaining an adjustment value of another gain mode based on the adjustment value of one gain mode stored in the adjustment value table and the gain difference, and this means is a gain. Take advantage of the difference.

  The low noise amplifier is preferably included in an integrated circuit, and the memory is provided in the integrated circuit.

  An integrated circuit according to the present invention is an integrated circuit including a low noise amplifier built in a mobile phone terminal having a communication unit that performs wireless communication with a base station. In this integrated circuit, the low noise amplifier has a function of selectively amplifying an RF signal received from a base station in one of a plurality of gain modes, and stores a gain difference between the plurality of gain modes. Provided with a memory.

  According to the present invention, it is possible to shorten the time required for solid adjustment of each terminal. As a result, the time required for mass production of terminals can be greatly reduced.

It is a block diagram which shows schematic hardware constitutions of the mobile telephone terminal in embodiment of this invention. It is the block diagram which showed the internal structure of the communication part in FIG. It is a figure which shows the numerical example of the adjustment value at the time of the input of the reference | standard RF signal in the multiple gain mode for every terminal. It is a figure which shows the example of the content of the adjustment value table hold | maintained at one terminal. It is a figure for demonstrating the example of an expansion of embodiment of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic hardware configuration of mobile phone terminal 100 in the present embodiment. The mobile phone terminal is also simply referred to as a terminal for convenience.

  The mobile phone terminal 100 includes a control unit 110, an antenna 111, a communication unit 112, a display unit 113, an operation unit 114, a storage unit 115, an audio processing unit 116, a speaker 117, and a microphone 118.

  The control unit 110 is connected to each unit via the bus 120 and is a unit that controls each unit and performs necessary data processing, and includes a processor such as a CPU.

  The communication unit 112 is a unit that performs radio communication with a base station using radio waves via an antenna, and includes an integrated circuit RF-IC 112a in the present embodiment.

  The display unit 113 is a means for providing a display interface to the user, and includes a display device such as an LCD or an organic EL that displays information on a display screen.

  The operation unit 114 is means for providing an input interface to the user, and includes input devices such as a numeric keypad and various control keys.

  The storage unit 115 is a unit that stores various application programs such as an OS and a communication application program as programs executed by the control unit 110 and necessary data, and includes a memory such as a ROM and a RAM. In the present embodiment, the storage unit 115 has an area for storing an adjustment value table 115a described later in a nonvolatile manner.

  The voice processing unit 116 is a means for processing received voices, voices of moving image files, and music data. The voice processing unit 116 includes a codec and is connected to a speaker 117 that outputs voices and a microphone 118 that collects voices to be sent. The

  FIG. 2 is a block diagram showing the internal configuration of the communication unit 112. The antenna changeover switch 209 switches between the built-in antenna 111 and the external antenna 202.

  A received wave received by the antenna passes through a duplexer 210 that operates as an antenna duplexer, is amplified by a low noise amplifier (LNA) 220, and a predetermined band signal is filtered by a band filter (SAF) 230. . The output of the band filter (SAF: SAw Filter) 230 is demodulated by a demodulator (QDem) 241, passes through the band filter 242 again, and is output as a received IQ signal. The demodulator 241 includes an automatic variable gain amplifier 241a. The demodulator 241 is controlled by a PLL (Phase Lock Loop) and a VCO (Voltage Controlled Oscillator) circuit 243 receiving the clock from the oscillator 250.

  The transmitted IQ signal is modulated by a modulator (QMod) 245. Modulator 245 is controlled by PLL and VCO 244 that have received the clock from oscillator 250. The output of the modulator 245 is amplified by the high frequency amplifier 246, and a predetermined band signal is filtered by the band filter 260. The output of the band filter 260 is power amplified by a power amplifier (PA) 270 and sent to the duplexer 210 via the isolator 280.

  In the present embodiment, the duplexer 210, the low noise amplifier 220, the band filter 230, the high frequency amplifier 246, the band filter 260, the power amplifier 270, and the isolator 280 each have a component corresponding to three bands, and have a desired band. It has a configuration that can be selectively used.

  Control of each unit in the communication unit 112 is executed by the control circuit 290 inside the communication unit under the control of the control unit 110 (FIG. 1).

  The low noise amplifier 220 has a function of selectively amplifying the RF signal received from the base station in one of a plurality of gain modes, and is configured by an integrated circuit (IC). This IC is provided as the RF-IC 112a shown in FIG. By the vendor of the RF-IC 112a, a gain difference specific to the IC as will be described later is stored in the memory 224 in a nonvolatile manner. The demodulator 241, the band filter 242, the PLL and VCO circuits 243 and 244, the modulator 245, and the high frequency amplifier 246 are also configured as an integrated circuit as the modulation / demodulation circuit 240. The modem circuit 240 and the low noise amplifier 220 may be configured as a single integrated circuit and used as the RF-IC 112a.

  In the communication unit 112, as described above, since it is necessary to report the level of input power corresponding to the received power (received electric field strength) at the antenna to the base station, solid adjustment is performed on the production line.

  FIG. 3 shows a numerical example of an adjustment value at the time of inputting a reference RF signal of power corresponding to a known reception level in the multiple gain mode for each terminal. Here, the AGC value at the time of inputting a reference RF signal of power (here, −50 dBm) corresponding to a known reception level in each of the Hi gain (high gain) mode and the Low gain (low gain) mode is obtained. That is, a reference RF signal of −50 dBm is input to the terminal, and the amplification degree (AGC value) of the automatic variable gain amplifier 241a is changed so that the IQ output signal becomes a certain target level (predetermined demodulation output level). The AGC value at that time is stored in the adjustment value table in a nonvolatile manner. As a result, when the AGC value for the reference RF signal of −50 dBm is determined in the gain mode of the terminal, when the RF signal of an unknown reception level is received, the reception level is calculated from the AGC value at that time. Can do.

For example, in the example of the terminal A in FIG. 3, when the AGC value obtained by measurement with respect to the reference RF signal of −50 dBm in the Hi gain mode is −2, the AGC value at the time of receiving the actual RF signal is −5. Then, the reception level RSSI value to be reported to the base station can be obtained as follows.
RSSI = -50-(-5-(-2)) =-47 dBm

Similarly, when the AGC value obtained by measurement with respect to the reference RF signal of −50 dBm in the low gain mode is +10, if the AGC value at the time of reception of the actual RF signal is +8, reception is reported to the base station. The level RSSI value can be obtained as follows.
RSSI = −50− (8− (10)) = − 48 dBm

  Such a measurement needs to be measured at the time of shipment for each terminal (in some cases, a plurality of channels in the band) for each terminal, and an adjustment value table needs to be stored. FIG. 4 shows an example of the contents of the adjustment value table 115a held in one terminal. In the figure, I, VI, and IX indicate bands, and L, M, and H indicate examples in which channels are divided into three ranges of high, medium, and low, and the AGC value of the gain mode is set for each range. .

  As described above, when the LNA has a plurality of gain modes, the time required for measurement increases accordingly.

  Therefore, in the present invention, by providing the RF-IC itself with a gain difference between a plurality of gain modes, at the time of shipment, the AGC value when the reference RF signal is input as described above for only one gain mode is set. Measurement is sufficient. For example, the measurement can be performed only in the Hi gain mode, and the AGC value when the reference RF signal is input in the Low gain mode can be calculated. In the example shown in FIG. 3, the RF-IC is shown as holding the gain difference for the terminal on which the RF-IC is mounted, but actually holds the gain difference for each band (and for each channel) of the terminal. I can keep it.

  In implementing the present invention, there are (1) a method for storing the AGC value for only one gain mode in the adjustment value table itself, and (2) a method for storing the AGC value for all gain modes.

  In the case of the first method, the adjustment value table 115a shown in FIG. 4 has an AGC value storage area only for one of the gain modes of Hi or Low. For other gain modes, the AGC value is obtained using the gain difference when calculating the RSSI value.

  In the case of the second method, the AGC value is actually measured for only one gain mode, but for the other gain modes, the gain difference stored in the RF-IC 112a is applied to the AGC value and the target value is obtained. An AGC value is obtained and stored in the adjustment value table 115a in a nonvolatile manner. This additional storage may be before shipment of the terminal or after shipment.

  By the way, the gain difference may change due to the secular change after the manufacture of the RF-IC. In addition, it may be found after the shipment of the RF-IC that the gain difference stored in the RF-IC has an error, or the stored value may be destroyed. In such a case, it is advantageous if the gain difference in the memory 224 in the RF-IC 112a can be updated afterwards.

  With reference to FIG. 5, an extension example of the present embodiment for dealing with such a problem will be described. The terminal 100 can be connected to the server 300 via the communication network 320. The communication network 320 is a local area network (LAN) or a wide area network (WAN). The use of the LAN corresponds to a case where a terminal manufacturer uses a private server before the terminal is shipped. The WAN may be used by a terminal manufacturer before shipping the terminal, or by the terminal itself after shipping, for example, using a server disclosed by an RF-IC vendor. The server 300 includes a database 310 that stores gain difference values corresponding to RF-IC identification information. The gain difference in the database 310 is sequentially updated according to the secular change for each lot of each chip ID. When a search request is given together with external RF-IC identification information, the server 300 searches for and returns a gain difference corresponding to the identification information. The identification information of the RF-IC is, for example, a chip ID and a lot number. The search request and the update of the gain difference can be performed automatically by an instruction from the terminal carrier to each terminal or with the approval of the terminal user. A search request may be made from the carrier system, and the system may update the gain difference in each terminal automatically or with the consent of the terminal user.

  The preferred embodiments of the present invention have been described above, but various modifications and changes other than those mentioned above can be made. For example, in the above description, the gain difference to the memory 224 is written by the vendor of the RF-IC 112a. However, in the example of using the server, each IC confirmed from the server in the terminal mass production line of the terminal manufacturer is used. It is also possible to write the original difference into the terminal.

  Although the communication unit 112 corresponds to a plurality of bands that can be switched, the plurality of bands are not essential elements in the present invention.

DESCRIPTION OF SYMBOLS 100 ... Mobile phone terminal 110 ... Control part 111 ... Antenna 112 ... Communication part 113 ... Display part 114 ... Operation part 115 ... Memory | storage part 115a ... Adjustment value table 116 ... Audio | voice processing part 117 ... Speaker 118 ... Microphone, 120 ... Bus, 202 ... External antenna, 209 ... Antenna changeover switch, 210 ... Duplexer, 220 ... Low noise amplifier, 224 ... Memory, 230 ... Band filter, 240 ... Modulation / demodulation circuit, 241 ... Demodulator, 241a ... automatic variable gain amplifier, 242 ... band filter, 243, 244 ... PLL and VCO circuit, 245 ... modulator, 246 ... high frequency amplifier, 250 ... oscillator, 260 ... band filter, 270 ... power amplifier, 280 ... isolator, 290 ... Control circuit, 300 ... server, 310 ... database, 320 ... communication Network

Claims (5)

A low noise amplifier that selectively amplifies an RF signal received from a base station in one of a plurality of gain modes;
A memory storing gain differences between a plurality of gain modes of the low noise amplifier;
An automatic variable gain amplifier receiving the output of the low noise amplifier;
An adjustment value table for storing, as an adjustment value, an amplification factor of the automatic variable gain amplifier that obtains a predetermined demodulated output level with respect to a reference RF signal of power corresponding to a known reception level;
Means for obtaining a received electric field intensity with reference to the adjustment value table according to the amplification degree of the automatic variable gain amplifier when an actual RF signal is received;
A mobile phone terminal that reports the obtained received electric field strength to the base station.   The mobile phone terminal according to claim 1, further comprising means for obtaining an adjustment value of another gain mode based on an adjustment value of one gain mode stored in the adjustment value table and the gain difference.   The mobile phone terminal according to claim 1, wherein the low noise amplifier is included in an integrated circuit, and the memory is provided in the integrated circuit.   4. The integrated circuit identification information is transmitted to a server via a communication network, a gain difference corresponding to the identification information is received from the server, and the gain difference in the memory is updated with the received gain difference. The mobile phone terminal described in 1. An integrated circuit including a low noise amplifier built in a mobile phone terminal having a communication unit that performs wireless communication with a base station,
The low noise amplifier has a function of selectively amplifying an RF signal received from a base station in one of a plurality of gain modes, and includes a memory storing a gain difference between the plurality of gain modes. Integrated circuit.

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