JP2003204364A - Receiver compatible with multiple modulation schemes - Google Patents
Receiver compatible with multiple modulation schemesInfo
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- JP2003204364A JP2003204364A JP2001401995A JP2001401995A JP2003204364A JP 2003204364 A JP2003204364 A JP 2003204364A JP 2001401995 A JP2001401995 A JP 2001401995A JP 2001401995 A JP2001401995 A JP 2001401995A JP 2003204364 A JP2003204364 A JP 2003204364A
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- modulation
- amplifier
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、無線機の受信部に
用いられる受信装置に係り、特に変調多値数の異なる複
数の変調方式に対応可能な受信装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver used in a receiver of a radio, and more particularly to a receiver capable of supporting a plurality of modulation schemes having different modulation multi-value numbers.
【０００２】[0002]
【従来の技術】近年、マルチメディア通信の需要の高ま
りに応じて、無線通信における伝送ビットレートの高レ
ート化が重要な課題となってきている。無線通信におい
て伝送レートを高くするためには広い帯域幅が必要であ
るが、周波数資源は有限であるため、周波数有効利用の
観点からは単純に帯域幅を広げて高ビットレートを実現
する方法は好ましくない。2. Description of the Related Art In recent years, as the demand for multimedia communication has increased, increasing the transmission bit rate in wireless communication has become an important issue. A wide bandwidth is required to increase the transmission rate in wireless communication, but since frequency resources are finite, a method of simply increasing the bandwidth to achieve a high bit rate is required from the viewpoint of effective frequency utilization. Not preferable.
【０００３】このような背景に鑑み、無線通信システム
の変調方式を多値ディジタル変調方式とすることによ
り、限られた帯域幅で高ビットレートの伝送を行う技術
の研究開発が盛んに試みられている。例えば、ＩＥＥＥ
８０２委員会の勧告による無線ＬＡＮ標準規格の一つ
であるＩＥＥＥ ８０２．１１ａでは、６４ＱＡＭ方式
を採用することによって、１シンボル当たり６ビットの
レートで伝送を行う。In view of such a background, by making the modulation system of the radio communication system a multi-level digital modulation system, research and development of a technique for transmitting at a high bit rate with a limited bandwidth has been actively attempted. There is. For example, IEEE
IEEE 802.11a, which is one of the wireless LAN standards recommended by the 802 committee, adopts the 64QAM method to perform transmission at a rate of 6 bits per symbol.
【０００４】多値変調方式は、伝搬環境が劣化すると正
しく受信することが困難となるという性質がある。そこ
で、ＩＥＥＥ ８０２．１１ａでは多値ディジタル変調
における変調多値数を可変とし、１シンボル当たり１ビ
ットの伝送を行うＢＰＳＫ、２ビットの伝送を行うＱＰ
ＳＫ、４ビットの伝送を行う１６ＱＡＭ及び６ビットの
伝送を行う６４ＱＡＭのいずれかを選択して伝送するこ
とを仕様に盛り込んでいる。変調多値数は、ＢＰＳＫが
２値、ＱＰＳＫが４値、１６ＱＡＭが１６値、６４ＱＡ
Ｍが６４値ということになる。このような多値ディジタ
ル変調を採用し、伝搬環境が劣化した場合は変調多値数
の小さい変調方式を用いることによって、通信を継続す
ることが可能となる。The multi-level modulation method has a property that it becomes difficult to receive correctly when the propagation environment deteriorates. Therefore, in IEEE 802.11a, the modulation multilevel number in multilevel digital modulation is made variable, and BPSK for transmitting 1 bit per symbol and QP for transmitting 2 bits.
The specification includes the selection and transmission of either SK, 16QAM for transmitting 4 bits or 64QAM for transmitting 6 bits. The number of modulation levels is 2 for BPSK, 4 for QPSK, 16 for 16QAM, and 64QA.
This means that M has 64 values. By adopting such multi-level digital modulation and using a modulation method with a small modulation multi-level number when the propagation environment deteriorates, it becomes possible to continue communication.
【０００５】このようにＩＥＥＥ ８０２．１１ａをは
じめとする高速無線通信システムは、変調方式すなわち
変調多値数を可変とすることで、常に誤りのない伝送を
可能とする仕様が盛り込まれている。ところが従来の無
線受信装置では、変調方式や伝送レートや伝搬環境にか
かわらずある一定の性能で動作しており、消費電流を無
駄に使っているという問題がある。As described above, the high-speed wireless communication system such as IEEE 802.11a has a specification that always enables error-free transmission by making the modulation method, that is, the modulation multi-value number variable. However, the conventional wireless receiver operates with a certain performance regardless of the modulation method, the transmission rate, and the propagation environment, and there is a problem that the current consumption is wasted.
【０００６】従来の受信装置ではアンテナにより受信さ
れた高周波信号は、まずＬＮＡ（Low Noise Amplifier;
低雑音増幅器）によって増幅された後、周波数変換器
により中間周波（Intermediate Frequency）信号に周波
数変換され、ＩＦ信号はＩＦＡ（Intermediate Frequen
cy Amplifier; 中間周波増幅器）によってさらに増幅さ
れる。ここで、ＩＦＡにはＶＧＡ（Variable Gain Ampl
ifier; 可変利得増幅器）が用いられる。ＶＧＡによっ
て増幅されたＩＦ信号は、直交復調器でベースバンドＩ
Ｑ信号へ周波数変換され、次にＡ／Ｄ変換器でディジタ
ル信号に変換されてからモデムに入力され、元の送信信
号が再生される。In the conventional receiver, the high frequency signal received by the antenna is first LNA (Low Noise Amplifier;
After being amplified by a low noise amplifier, the frequency signal is frequency-converted into an intermediate frequency (Intermediate Frequency) signal by an IF signal (IFA).
cy Amplifier; intermediate frequency amplifier) further amplified. Here, the IFA has a VGA (Variable Gain Ampl).
variable gain amplifier) is used. The IF signal amplified by the VGA is quadrature demodulated by the baseband I.
The signal is frequency-converted into a Q signal, then converted into a digital signal by an A / D converter, and then input to a modem to reproduce the original transmission signal.
【０００７】Ａ／Ｄ変換器の出力からＲＳＳＩ（Receiv
ing Signal Strength Indicator;受信電界強度）が検出
され、これに基づき生成されたＡＧＣ（Automatic Gain
Control）信号がＶＧＡにフィードバックされる。ＶＧ
Ａの利得は、このＡＧＣ信号によってＡ／Ｄ変換器の入
力信号レベルが常に一定になるように制御される。すな
わち、受信信号が弱くなってきたときはＶＧＡの利得を
上げ、受信信号が強くなってきたときはＶＧＡの利得を
下げるようにＡＧＣ動作が行われる。From the output of the A / D converter, RSSI (Receiv
ing Signal Strength Indicator) is detected, and AGC (Automatic Gain) generated based on this is detected.
Control) signal is fed back to the VGA. VG
The gain of A is controlled by the AGC signal so that the input signal level of the A / D converter is always constant. That is, the AGC operation is performed so that the VGA gain is increased when the received signal becomes weak and the VGA gain is decreased when the received signal becomes strong.
【０００８】このような従来の受信装置をＩＥＥＥ ８
０２．１１ａのような複数の変調方式に対応した無線通
信システムに適用した場合、次のような問題点がある。
従来の受信装置は、一つの変調方式にのみ対応するよう
に最適設計されているのが通常であり、ＡＧＣはＲＳＳ
Ｉのみを判断基準に行われていた。複数の変調方式に対
応する場合には、ＲＳＳＩのみに基づいてＡＧＣを行っ
た場合、ある変調方式ではＬＮＡとＶＧＡの利得配分が
最適であったとしても、他の変調方式では必ずしもそう
ではない可能性がある。例えば、６４ＱＡＭで最適な特
性が得られるようにＬＮＡとＶＧＡの利得配分を設計し
ていた場合、同じ受信電界強度のＢＰＳＫ信号が受信さ
れた時には、必要以上に受信装置の総合ＮＦ（雑音指
数）が良くなる可能性がある。これは言い換えれば、消
費電流を大量に消費して必要以上に受信装置の特性を良
くしているということになる。Such a conventional receiving device is referred to as IEEE 8
When applied to a wireless communication system supporting a plurality of modulation schemes such as 02.11a, there are the following problems.
Conventional receivers are usually optimally designed to support only one modulation method.
Only I was judged. In the case of supporting multiple modulation schemes, when AGC is performed based only on RSSI, even if the gain distribution of LNA and VGA is optimal in a certain modulation scheme, it may not be so in other modulation schemes. There is a nature. For example, when the gain distribution of LNA and VGA is designed so that optimum characteristics can be obtained with 64QAM, the total NF (noise figure) of the receiving device is unnecessarily increased when a BPSK signal having the same received electric field strength is received. May improve. In other words, this means that a large amount of current is consumed and the characteristics of the receiving device are improved more than necessary.
【０００９】[0009]
【発明が解決しようとする課題】このように従来の受信
装置での利得配分は、予め定められた変調方式、伝送レ
ートで最適な性能が発揮されるように設計されていたた
めに、複数の変調方式に対応させた場合には利得配分が
最適でない場合が生じ、このため所要の受信特性が得ら
れなかったり、逆に過剰な受信特性と無駄な消費電流の
増大を生じるという極めて重大な欠点を有していた。As described above, the gain distribution in the conventional receiving apparatus is designed so that optimum performance is exhibited at a predetermined modulation method and transmission rate. Therefore, a plurality of modulation methods are used. When the system is used, the gain distribution may not be optimal, and thus the required reception characteristics may not be obtained, or conversely, excessive reception characteristics and useless increase in current consumption may occur. Had.
【００１０】本発明は、このような問題点を解消し、複
数の変調方式において良好な受信特性と省電力を実現で
きる複数の変調方式に対応可能な受信装置を提供するこ
とを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a receiving apparatus which can cope with a plurality of modulation schemes and can realize good reception characteristics and power saving in a plurality of modulation schemes.
【００１１】[0011]
【課題を解決するための手段】上記の課題を解決するた
め、本発明の一つの態様に係る受信装置は、無線通信シ
ステムにおける変調多値数の異なる複数の変調方式に対
応可能な受信装置において、高周波信号を受信する受信
手段と、受信した高周波信号を増幅する利得可変の第１
の増幅器と、増幅された高周波信号をより低い周波数に
変換して周波数変換信号を出力する周波数変換器と、周
波数変換信号を増幅する利得可変の第２の増幅器と、第
１及び第２の増幅器の利得配分を前記変調方式に従って
決定し、該決定した利得配分に従って第１及び第２の増
幅器の利得を制御する利得制御部とを有することを基本
的な特徴とする。In order to solve the above problems, a receiving apparatus according to one aspect of the present invention is a receiving apparatus capable of supporting a plurality of modulation schemes with different modulation multi-value numbers in a wireless communication system. Receiving means for receiving the high frequency signal, and a variable gain first unit for amplifying the received high frequency signal
Amplifier, a frequency converter for converting the amplified high frequency signal to a lower frequency and outputting the frequency converted signal, a variable gain second amplifier for amplifying the frequency converted signal, and first and second amplifiers And a gain control unit for controlling the gains of the first and second amplifiers according to the determined gain distribution.
【００１２】本発明の他の態様に係る受信装置は、受信
装置の受信電界強度検出部を有し、利得制御部は第１及
び第２の増幅器の利得配分を変調方式及び検出された受
信電界強度に従って決定し、該決定した利得配分に従っ
て第１及び第２の増幅器の利得を制御することを特徴と
する。A receiving apparatus according to another aspect of the present invention has a receiving electric field strength detecting section of the receiving apparatus, wherein the gain control section modulates the gain distribution of the first and second amplifiers and the detected receiving electric field. It is characterized in that the gain of the first and second amplifiers is controlled according to the determined intensity distribution according to the determined gain distribution.
【００１３】[0013]
【発明の実施の形態】（第１の実施形態）図１は、本発
明の第１の実施形態に係る受信装置の構成を示してい
る。本実施形態は、シングルスーパーヘテロダイン方式
の受信装置に適用した例である。ただし、図１は受信部
に必要な全ての構成要素を示してはおらず、例えばフィ
ルタのような本発明を説明する上で本質的でない要素に
ついては、図示を省略している。BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) FIG. 1 shows the configuration of a receiving apparatus according to the first embodiment of the present invention. The present embodiment is an example applied to a single super-heterodyne receiver. However, FIG. 1 does not show all the components necessary for the receiving unit, and elements such as a filter which are not essential for explaining the present invention are not shown.
【００１４】図１において、アンテナ１００で受信され
た高周波信号は、ＬＮＡ（Low Noise Amplifier; 低雑
音増幅器）１０１により増幅された後、周波数変換器１
０２によって周波数変換されることにより、中間周波数
信号とされる。中間周波数信号はＩＦＡ（Intermediate
Frequency Amplifier; 中間周波増幅器）１０３により
増幅された後、直交復調器１０４によりベースバンド直
交信号（ＩＱ信号）へ変換される。ベースバンド直交信
号はＡ／Ｄ変換器１０５（ＡＤＣ）によってディジタル
化され、モデム１０６に入力される。モデム１０６で
は、ディジタル化されたベースバンド直交信号から音声
信号やデータ信号などの再生信号２００が生成される。In FIG. 1, a high frequency signal received by an antenna 100 is amplified by an LNA (Low Noise Amplifier) 101, and then a frequency converter 1
The frequency is converted by 02 to be an intermediate frequency signal. The intermediate frequency signal is IFA (Intermediate
After being amplified by a frequency amplifier (intermediate frequency amplifier) 103, it is converted into a baseband quadrature signal (IQ signal) by a quadrature demodulator 104. The baseband quadrature signal is digitized by the A / D converter 105 (ADC) and input to the modem 106. The modem 106 generates a reproduction signal 200 such as a voice signal or a data signal from the digitized baseband quadrature signal.
【００１５】ＬＮＡ１０１及びＩＦＡ１０３は、共にＶ
ＧＡ（Variable Gain Amplifier;可変利得増幅器）が用
いられる。すなわち、従来ではＬＮＡは固定利得もしく
は単純な二段切替え利得増幅器が用いられていたが、本
実施形態ではＬＮＡ１０１にも、ＩＦＡ１０３と同様に
連続的な利得可変ができるＶＧＡが用いられる。近年の
回路技術の進歩により、このようにＩＦＡ１０３のみな
らず、ＬＮＡ１０１においても連続的な利得可変が可能
となっている。ＬＮＡ１０１及びＩＦＡ１０３の利得
は、次のように制御される。Both LNA 101 and IFA 103 have V
A GA (Variable Gain Amplifier) is used. That is, in the past, the LNA used a fixed gain or a simple two-stage switching gain amplifier, but in the present embodiment, the LNA 101 also uses a VGA capable of continuously varying the gain, like the IFA 103. Due to the recent progress in circuit technology, continuous gain variation is possible not only in the IFA 103 but also in the LNA 101. The gains of the LNA 101 and IFA 103 are controlled as follows.
【００１６】Ａ／Ｄ変換器１０５の出力はＲＳＳＩ（Re
ceiving Signal Strength Indicator; 受信電界強度）
検出部１０７にも入力される。ＲＳＳＩ検出部１０７か
らは、受信電界強度を示す情報（受信電界強度情報）２
０２が出力される。一方、モデム１０６からは再生信号
２００とは別に、受信信号の変調方式を示す情報（変調
方式情報）２０１が出力される。The output of the A / D converter 105 is RSSI (Re
ceiving Signal Strength Indicator)
It is also input to the detection unit 107. Information (reception field strength information) 2 indicating the reception field strength from the RSSI detector 107
02 is output. On the other hand, in addition to the reproduced signal 200, the modem 106 outputs information (modulation method information) 201 indicating the modulation method of the received signal.
【００１７】利得制御部１０８は、利得配分決定部１０
９及び利得制御信号発生部１１０を有する。利得配分決
定部１０９では、変調方式情報２０１及び受信電界強度
情報２０２に従ってＬＮＡ１０１及びＩＦＡ１０３の利
得配分を決定し、ＬＮＡ１０１及びＩＦＡ１０３に設定
する利得を算出する。利得制御信号発生部１１０は、利
得配分決定部１０９で決定された利得配分に従って得ら
れる利得の情報に基づいて、ＬＮＡ利得制御信号２０３
及びＩＦＡ利得制御信号（ＡＧＣ信号）２０４を生成
し、それぞれＬＮＡ１０１及びＩＦＡ１０３の利得制御
信号入力端子に供給する。The gain control unit 108 includes a gain distribution determination unit 10
9 and a gain control signal generator 110. The gain distribution determining unit 109 determines the gain distribution of the LNA 101 and the IFA 103 according to the modulation method information 201 and the received electric field strength information 202, and calculates the gain set in the LNA 101 and the IFA 103. The gain control signal generation unit 110, based on the gain information obtained according to the gain distribution determined by the gain distribution determination unit 109, the LNA gain control signal 203.
And IFA gain control signal (AGC signal) 204 are generated and supplied to the gain control signal input terminals of the LNA 101 and IFA 103, respectively.
【００１８】次に、本実施形態における利得制御部１０
８による利得制御の具体例について説明する。図１に示
すような受信装置の設計においてＬＮＡ１０１及びＩＦ
Ａ１０３の利得配分を行う場合、ＬＮＡ１０１の利得配
分を減らし、ＩＦＡ１０３の利得配分を増やすほど受信
装置の総合ＮＦ（Noise Factor；雑音指数）は劣化する
が、消費電流は減少する。すなわち、なるべく低い周波
数のところで受信装置全体としての利得を稼いだ方が低
消費電力となるが、その反面、受信装置の総合ＮＦが劣
化する。逆に、ＬＮＡ１０１の利得配分を増やし、ＩＦ
Ａ１０３の利得配分を減らすと、受信装置としての総合
ＮＦは改善されるが、消費電流が増えてしまう。Next, the gain controller 10 in this embodiment.
A specific example of the gain control by 8 will be described. In the design of the receiver as shown in FIG. 1, the LNA 101 and the IF
When the gain distribution of A103 is performed, as the gain distribution of the LNA 101 is reduced and the gain distribution of the IFA 103 is increased, the total NF (Noise Factor) of the receiving device deteriorates, but the current consumption decreases. That is, the power consumption is reduced by gaining the gain of the receiving device as a whole at a frequency as low as possible, but on the other hand, the total NF of the receiving device is deteriorated. On the contrary, increase the gain distribution of LNA 101
When the gain distribution of A103 is reduced, the total NF as a receiving device is improved, but the current consumption increases.
【００１９】このような問題を解決するため、本実施形
態の受信装置では、ある受信電界強度と特定の変調方式
の下で通信を行っている状態から、変調方式がモデム１
０６からの指示などで変更されたとき、ＬＮＡ１０１及
びＩＦＡ１０３の利得配分を次のように変更する。In order to solve such a problem, in the receiving apparatus of the present embodiment, the modulation method is the modem 1 from the state where communication is performed under a certain reception electric field strength and a specific modulation method.
When it is changed by the instruction from 06, the gain distribution of the LNA 101 and the IFA 103 is changed as follows.
【００２０】（ａ）変調方式が変調多値数のより大きい
変調方式に変更された場合：ＬＮＡ１０１の利得を上
げ、かつＩＦＡ１０３の利得を下げる制御信号２０３及
び２０４が利得制御部１０８より出力される。これによ
り受信装置の総合ＮＦが改善され、受信特性を向上させ
ることができる。
（ｂ）変調方式が変調多値数のより小さい変調方式に変
更された場合：ＬＮＡ１０１の利得を下げ、かつＩＦＡ
１０３の利得を上げる制御信号２０３及び２０４が利得
制御部１０８より出力される。これによって、受信装置
の消費電流の削減を図ることができる。受信装置の電源
に電池を用いている場合、電池の消耗を防止することが
可能となる。このように本実施形態によると、変調方式
に応じて最適な利得配分を決定することが可能となり、
受信特性の向上と受信装置の低消費電力化を実現するこ
とができる。(A) When the modulation system is changed to a modulation system having a larger modulation level: control signals 203 and 204 that increase the gain of the LNA 101 and decrease the gain of the IFA 103 are output from the gain control unit 108. . As a result, the total NF of the receiving device is improved, and the receiving characteristic can be improved. (B) When the modulation method is changed to a modulation method with a smaller number of modulation levels: the gain of the LNA 101 is lowered, and IFA
Control signals 203 and 204 for increasing the gain of 103 are output from gain control section 108. As a result, the current consumption of the receiving device can be reduced. When a battery is used as the power source of the receiving device, it is possible to prevent the battery from being consumed. As described above, according to the present embodiment, it is possible to determine the optimum gain distribution according to the modulation method,
It is possible to improve the reception characteristics and reduce the power consumption of the reception device.
【００２１】（第２の実施形態）次に、本発明の第２の
実施形態について説明する。本実施形態では、図１に示
した受信装置において、変調方式に従った利得制御部１
０８によるＬＮＡ１０１及びＩＦＡ１０３の利得配分を
以下のように決定する。各変調方式において同じＢＥＲ
（Bit Error Rate；ビット誤り率）を得るのに必要なＣ
ＮＲ（Carrier toNoise Ratio；キャリア・ノイズ比）
が次表１のように異なっている場合を例として挙げる。(Second Embodiment) Next, a second embodiment of the present invention will be described. In the present embodiment, in the receiving device shown in FIG. 1, the gain control unit 1 according to the modulation method is used.
The gain distribution of LNA 101 and IFA 103 by 08 is determined as follows. Same BER for each modulation method
C required to obtain (Bit Error Rate)
NR (Carrier to Noise Ratio)
As an example, the case where is different as shown in the following table 1 is given.
【００２２】[0022]
【表１】 [Table 1]
【００２３】この例では変調方式としてＢＰＳＫ，ＱＰ
ＳＫ，１６ＱＡＭ，６４ＱＡＭを想定しており、各々の
所要ＣＮＲは表１中に示した通りである。６４ＱＡＭを
基準にすると、１６ＱＡＭは５ｄＢ、ＱＰＳＫは１０ｄ
Ｂ、ＢＰＳＫは１３ｄＢだけ、それぞれＣＮＲが６４Ｑ
ＡＭの場合より小さくとも、同一のＢＥＲで復調ができ
る。In this example, the modulation method is BPSK, QP
SK, 16QAM and 64QAM are assumed, and the required CNR for each is as shown in Table 1. Based on 64QAM, 16QAM is 5dB and QPSK is 10d.
B and BPSK are only 13 dB, and CNR is 64Q.
Even if smaller than the case of AM, demodulation can be performed with the same BER.
【００２４】従って、仮に受信装置の総合ＮＦが７ｄＢ
であるとすると、表１より変調方式が６４ＱＡＭから１
６ＱＡＭに変更されたとき、所要ＣＮＲは５ｄＢ緩和さ
れるため、受信装置の総合ＮＦは５ｄＢ劣化することが
許容される。そこで、ＬＮＡ１０１の利得を５ｄＢ減ら
し、ＩＦＡ１０３の利得を５ｄＢ増やすように利得制御
部１０８から利得制御信号２０３及び２０４が出力され
る。Therefore, it is assumed that the total NF of the receiving device is 7 dB.
Then, from Table 1, the modulation method is 64QAM to 1
When the QNR is changed to 6QAM, the required CNR is relaxed by 5 dB, so that the total NF of the receiving device is allowed to deteriorate by 5 dB. Therefore, gain control signals 203 and 204 are output from gain control section 108 so that the gain of LNA 101 is reduced by 5 dB and the gain of IFA 103 is increased by 5 dB.
【００２５】変調方式が１６ＱＡＭからＱＰＳＫに変更
されたときは、所要ＣＮＲはさらに５ｄＢ緩和される。
このときは、同様にＬＮＡ１０１の利得を５ｄＢさらに
減らし、ＩＦＡ１０３の利得をさらに５ｄＢ増やすよう
に、利得制御部１０８から利得制御信号２０３及び２０
４が出力される。When the modulation scheme is changed from 16QAM to QPSK, the required CNR is further relaxed by 5 dB.
At this time, similarly, the gain control unit 203 increases the gain of the LNA 101 by 5 dB and further increases the gain of the IFA 103 by 5 dB.
4 is output.
【００２６】このように本実施形態においては、変調方
式が変更されたときＬＮＡ１０１及びＩＦＡ１０３の利
得可変幅が変調方式の変更前と変更後の各々の変調方式
における所要ＣＮＲの差（上記の例では、５ｄＢ）とほ
ぼ等しくなるように、ＬＮＡ１０１及びＩＦＡ１０３の
利得配分を決定する。これによって、受信装置は常に必
要最低限のＮＦを確保すると共に、極めて低消費電力で
動作することが可能となる。実際には、例示した受信装
置の総合ＮＦや所要ＣＮＲは異なる場合があるが、その
場合においても本実施形態の受信装置は上記と同様に動
作を行い、基本的に同様の効果を得ることができる。As described above, in this embodiment, when the modulation method is changed, the variable gain width of the LNA 101 and the IFA 103 is the difference in the required CNR between the modulation method before and after the change of the modulation method (in the above example, 5 dB), the gain distribution of the LNA 101 and the IFA 103 is determined so as to be approximately equal to 5 dB). As a result, the receiving device can always secure the minimum necessary NF and can operate with extremely low power consumption. In practice, the total NF and the required CNR of the exemplified receiving device may be different, but even in that case, the receiving device of the present embodiment operates similarly to the above, and basically the same effect can be obtained. it can.
【００２７】（第３の実施形態）次に、本発明の第３の
実施形態について説明する。本実施形態においても、受
信装置の構成は第１及び第２の実施形態と同様である。
第２の実施形態では、変調方式が変調多値数の異なる方
式に変更された場合、変調方式毎の所要ＣＮＲに対応さ
せて、変更後の変調方式の変調多値数に応じてＬＮＡ１
０１の利得を上下させることで、受信装置の総合ＮＦを
変えて低消費電力化を図っている。第３の実施形態で
は、第２の実施形態における利得配分の決定をさらに適
応化し、変調方式（変調多値数）及び受信電界強度に応
じて利得配分を変化させる。本実施形態における具体的
な利得制御方法を以下に示す。(Third Embodiment) Next, a third embodiment of the present invention will be described. Also in this embodiment, the configuration of the receiving device is the same as that of the first and second embodiments.
In the second embodiment, when the modulation scheme is changed to a scheme having a different modulation multi-level number, the LNA1 is made to correspond to the required CNR for each modulation scheme and according to the modulation multi-level number of the changed modulation scheme.
By raising or lowering the gain of 01, the total NF of the receiving device is changed to reduce the power consumption. In the third embodiment, the determination of the gain distribution in the second embodiment is further adapted, and the gain distribution is changed according to the modulation scheme (multi-level modulation number) and the received electric field strength. A specific gain control method in this embodiment will be described below.
【００２８】一例として、各変調方式において必要な最
低及び最高受信電界強度と受信信号のダイナミックレン
ジが次式の通りに定められているものとする。As an example, it is assumed that the minimum and maximum received electric field strengths and the dynamic range of the received signal required in each modulation system are defined as follows.
【００２９】[0029]
【表２】 [Table 2]
【００３０】一般的に、ＬＮＡ１０１の利得可変幅はダ
イナミックレンジより狭いため、受信電界強度が予め定
められた所定の閾値よりも小さい場合には、ＬＮＡ１０
１の利得を受信電界強度に応じて制御し、受信電界強度
が閾値以上の高いレベルの場合には、ＬＮＡ１０１の利
得を最低にした上で、ＩＦＡ１０３の利得を受信電界強
度に応じて制御することによって、残りの必要な利得を
ＩＦＡ１０３で稼ぐようにする。例えば、ＬＮＡ１０１
の利得可変範囲が＋８ｄＢ〜−７ｄＢ（利得可変幅は１
５ｄＢ）の場合の受信電界強度と利得設定との関係をＢ
ＰＳＫとＱＰＳＫの場合に関して以下の表に示す。Generally, the gain variable width of the LNA 101 is narrower than the dynamic range. Therefore, when the received electric field strength is smaller than a predetermined threshold value, the LNA 10
The gain of 1 is controlled according to the received electric field strength, and when the received electric field strength is at a high level equal to or higher than a threshold value, the gain of the LNA 101 is minimized and then the gain of the IFA 103 is controlled according to the received electric field strength. Thus, the IFA 103 is made to earn the remaining necessary gain. For example, LNA101
Gain variable range is +8 dB to -7 dB (gain variable width is 1
5 dB), the relationship between the received electric field strength and the gain setting is B
The table below shows the cases for PSK and QPSK.
【００３１】[0031]
【表３】 [Table 3]
【００３２】表３に示したように、ＬＮＡ１０１の利得
可変範囲（＋８ｄＢ〜−７ｄＢ）内では、第２の実施形
態と同様にＢＰＳＫの場合とＱＰＳＫの場合でＬＮＡ１
０１に２ｄＢの利得差を設けることで、必要な総合ＮＦ
を確保しつつ消費電流の低減を図っている。また、前述
したように受信電界強度がある閾値（ＢＰＳＫの場合は
−６７ｄＢｍ、ＱＰＳＫの場合は−６５ｄＢｍ）に達す
ると、ＬＮＡ１０１の利得を利得可変範囲の下限値（−
７ｄＢ）に固定し、受信電界強度の増加に伴いＩＦＡ１
０３の利得を下げるように全体の利得設定が行われる。As shown in Table 3, within the gain variable range (+8 dB to -7 dB) of the LNA 101, the LNA1 is different between the case of BPSK and the case of QPSK as in the second embodiment.
By adding a gain difference of 2 dB to 01, the required total NF
The current consumption is reduced while ensuring the above. Further, as described above, when the received electric field strength reaches a certain threshold value (-67 dBm in the case of BPSK, -65 dBm in the case of QPSK), the gain of the LNA 101 is set to the lower limit value of the variable gain range (-
Fixed to 7 dB) and the IFA1
The overall gain setting is performed so as to reduce the gain of 03.
【００３３】（第４の実施形態）図２は、本発明の第４
の実施形態に係る受信装置の構成を示す図である。図１
に示した第１の実施形態においては、ＲＳＳＩ検出部１
０７の入力はＡ／Ｄ変換器１０５の出力から取り出す構
成としているが、図２に示すようにＩＦ段、例えばＩＦ
Ａ１０３の出力から取り出すようにしてもよい。(Fourth Embodiment) FIG. 2 shows a fourth embodiment of the present invention.
It is a figure which shows the structure of the receiver which concerns on embodiment of FIG. Figure 1
In the first embodiment shown in FIG.
Although the input of 07 is taken out from the output of the A / D converter 105, as shown in FIG.
You may make it take out from the output of A103.
【００３４】さらに、上述の各実施形態では、スーパー
へテロダイン方式の受信装置について述べたが、本発明
による利得配分決定手法はダイレクトコンバージョンそ
の他の方式の受信装置にも同様に適用が可能である。Furthermore, in each of the above-described embodiments, the super-heterodyne type receiving apparatus has been described, but the gain distribution determination method according to the present invention can be similarly applied to the receiving apparatus of the direct conversion or other type.
【００３５】[0035]
【発明の効果】以上説明したように、本発明によれば複
数の変調方式に対応する受信装置において受信した高周
波信号を増幅する第１の増幅器と周波数変換信号を増幅
する第２の増幅器の利得配分を最適化することが可能と
なり、複数の変調方式において良好な受信特性と省電力
を実現することができる。As described above, according to the present invention, the gains of the first amplifier for amplifying the high frequency signal and the second amplifier for amplifying the frequency converted signal which are received by the receiving apparatus corresponding to a plurality of modulation systems are provided. The distribution can be optimized, and good reception characteristics and power saving can be realized in a plurality of modulation systems.
【図１】本発明の一実施形態に係る受信装置の構成を示
すブロック図FIG. 1 is a block diagram showing a configuration of a receiving device according to an embodiment of the present invention.
【図２】本発明の他の実施形態に係る受信装置の構成を
示すブロック図FIG. 2 is a block diagram showing a configuration of a receiving device according to another embodiment of the present invention.
１００…アンテナ １０１…低雑音増幅器 １０２…周波数変換器 １０３…中間周波増幅器 １０４…直交復調器 １０５…Ａ／Ｄ変換器 １０６…モデム １０７…受信電界強度検出部 １０８…利得制御部 １０９…利得配分決定部 １１０…利得制御信号発生部 ２００…再生信号 ２０１…変調方式情報 ２０２…受信電界強度情報 ２０３…ＬＮＡ利得制御信号 ２０４…ＡＧＣ信号 100 ... antenna 101 ... Low noise amplifier 102 ... Frequency converter 103 ... Intermediate frequency amplifier 104 ... Quadrature demodulator 105 ... A / D converter 106 ... Modem 107 ... Received field strength detector 108 ... Gain control unit 109 ... Gain distribution determination unit 110 ... Gain control signal generator 200 ... Playback signal 201 ... Modulation method information 202 ... Received field strength information 203 ... LNA gain control signal 204 ... AGC signal
Claims (5)
可能な受信装置において、 高周波信号を受信する受信手段と、 受信した高周波信号を増幅する利得可変の第１の増幅器
と、 増幅された高周波信号をより低い周波数に変換して周波
数変換信号を出力する周波数変換器と、 前記周波数変換信号を増幅する利得可変の第２の増幅器
と、 前記第１及び第２の増幅器の利得配分を前記変調方式に
従って決定し、該決定した利得配分に従って前記第１及
び第２の増幅器の利得を制御する利得制御部とを具備す
る複数の変調方式に対応可能な受信装置。1. A receiving device capable of supporting a plurality of modulation systems having different modulation multi-value numbers, a receiving means for receiving a high frequency signal, a variable gain first amplifier for amplifying the received high frequency signal, and an amplifier for amplifying the received high frequency signal. A frequency converter that converts the high-frequency signal to a lower frequency and outputs the frequency-converted signal; a variable gain second amplifier that amplifies the frequency-converted signal; and a gain distribution of the first and second amplifiers. A receiving apparatus capable of supporting a plurality of modulation methods, comprising a gain control unit that determines the gain according to the modulation method and controls the gains of the first and second amplifiers according to the determined gain distribution.
可能な受信装置において、 高周波信号を受信する受信手段と、 受信した高周波信号を増幅する利得可変の第１の増幅器
と、 増幅された高周波信号をより低い周波数に変換して周波
数変換信号を出力する周波数変換器と、 前記周波数変換信号を増幅する利得可変の第２の増幅器
と、 前記受信装置の受信電界強度を検出する受信電界強度検
出部と、 前記第１及び第２の増幅器の利得配分を前記変調方式及
び前記検出された受信電界強度に従って決定し、該決定
した利得配分に従って前記第１及び第２の増幅器の利得
を制御する利得制御部とを具備する複数の変調方式に対
応可能な受信装置。2. A receiving device capable of supporting a plurality of modulation systems having different modulation multi-value numbers, a receiving means for receiving a high frequency signal, a variable gain first amplifier for amplifying the received high frequency signal, and an amplifier for amplifying the received high frequency signal. A frequency converter that converts a high-frequency signal to a lower frequency and outputs a frequency-converted signal, a variable-gain second amplifier that amplifies the frequency-converted signal, and a reception electric field that detects a reception electric field strength of the reception device. An intensity detector, determining gain distributions of the first and second amplifiers according to the modulation scheme and the detected received electric field intensity, and controlling gains of the first and second amplifiers according to the determined gain distributions. A receiver capable of supporting a plurality of modulation schemes, which comprises a gain control unit.
調多値数のより大きい方式に変更された場合には前記第
１の増幅器の利得配分を前記第２の増幅器の利得配分に
対して相対的に増加させ、前記変調方式が前記変調多値
数のより小さい方式に変更された場合には前記第１の増
幅器の利得配分を前記第２の増幅器の利得配分に対して
相対的に減少させることを特徴とする請求項１または２
記載の複数の変調方式に対応可能な受信装置。3. The gain control unit sets the gain distribution of the first amplifier to the gain distribution of the second amplifier when the modulation system is changed to a system having a larger modulation multilevel number. Relative to the gain distribution of the second amplifier when the modulation system is changed to a system having a smaller modulation multi-level number. It reduces, It is characterized by the above-mentioned.
A receiver capable of supporting a plurality of modulation methods described.
れたとき前記第１及び第２の増幅器の利得可変幅が前記
変調方式の変更前と変更後における所要ＣＮＲの差とほ
ぼ等しくなるように前記第１及び第２の増幅器の利得配
分を決定することを特徴とする請求項３記載の複数の変
調方式に対応可能な受信装置。4. The gain control section, when the modulation method is changed, the gain variable widths of the first and second amplifiers become substantially equal to the difference between the required CNR before and after the change of the modulation method. 4. The receiving apparatus capable of supporting a plurality of modulation schemes according to claim 3, wherein the gain distribution of the first and second amplifiers is determined as described above.
界強度が所定の閾値以下の場合は、前記第１の増幅器の
利得を該受信電界強度に応じて可変制御し、前記検出さ
れた受信電界強度が前記閾値を越えた場合は、前記第１
の増幅器の利得を下限値に固定させた上で前記第２の増
幅器の利得を該受信電界強度に応じて可変制御すること
を特徴とする請求項２記載の複数の変調方式に対応可能
な受信装置。5. The gain control unit variably controls the gain of the first amplifier according to the received electric field strength when the detected received electric field strength is less than or equal to a predetermined threshold, and the detected electric field strength is detected. When the received electric field strength exceeds the threshold value, the first
3. The reception compatible with a plurality of modulation systems according to claim 2, wherein the gain of the second amplifier is fixed to a lower limit value, and the gain of the second amplifier is variably controlled according to the reception electric field strength. apparatus.
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|---|---|---|---|
| JP2001401995A JP3626454B2 (en) | 2001-12-28 | 2001-12-28 | Receiver capable of supporting multiple modulation systems |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001401995A JP3626454B2 (en) | 2001-12-28 | 2001-12-28 | Receiver capable of supporting multiple modulation systems |
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| Publication Number | Publication Date |
|---|---|
| JP2003204364A true JP2003204364A (en) | 2003-07-18 |
| JP3626454B2 JP3626454B2 (en) | 2005-03-09 |
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ID=27640387
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|---|---|---|---|
| JP2001401995A Expired - Fee Related JP3626454B2 (en) | 2001-12-28 | 2001-12-28 | Receiver capable of supporting multiple modulation systems |
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| WO2008084868A1 (en) * | 2007-01-12 | 2008-07-17 | Netindex Inc. | Signal control device and signal control method |
| JP2008172593A (en) * | 2007-01-12 | 2008-07-24 | Netindex Inc | Signal controller, and signal control method |
| JP2015185902A (en) * | 2014-03-20 | 2015-10-22 | Ｅｇｒｅｔｃｏｍ株式会社 | Modem device and communication system |
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