JP3186847B2 - C / N measuring device - Google Patents
C / N measuring deviceInfo
- Publication number
- JP3186847B2 JP3186847B2 JP19988792A JP19988792A JP3186847B2 JP 3186847 B2 JP3186847 B2 JP 3186847B2 JP 19988792 A JP19988792 A JP 19988792A JP 19988792 A JP19988792 A JP 19988792A JP 3186847 B2 JP3186847 B2 JP 3186847B2
- Authority
- JP
- Japan
- Prior art keywords
- carrier
- measuring
- correction value
- measured
- noise
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
- Monitoring And Testing Of Transmission In General (AREA)
- Radio Relay Systems (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、１つの帯域を複数の搬
送波に分割して利用するマルチキャリア衛星通信方式に
適した信号対雑音比（Ｃ／Ｎ）測定装置に関する。静止
衛星を中継器として利用する衛星通信は、広域に分散す
る多数の加入者間を通信接続するのに優れているという
点で注目されている。この接続性を最大限に引き出す手
段の１つとしてマルチキャリアＴＤＭＡ方式が研究開発
されている。このマルチキャリアＴＤＭＡ方式では多数
の搬送波を時分割し、かつ、搬送波も時分割で切りかえ
るものである。すなわち通常のＴＤＭＡ通信方式では一
波の搬送波を時分割的に各局が利用するのに対し、マル
チキャリアＴＤＭＡ通信方式では時間のみならず、周波
数に対しても分割される為非常に多くのコネクティビテ
ィをもたすことが可能となる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal-to-noise ratio (C / N) measuring apparatus suitable for a multicarrier satellite communication system in which one band is divided into a plurality of carriers and used. 2. Description of the Related Art Satellite communication using a geostationary satellite as a transponder has attracted attention because it is excellent for communication connection between a large number of subscribers distributed over a wide area. As one of means for maximizing this connectivity, a multicarrier TDMA system has been researched and developed. In this multi-carrier TDMA system, a large number of carriers are time-divided, and the carriers are also switched in a time-division manner. That is, in the ordinary TDMA communication system, each carrier uses one carrier in a time-division manner, whereas in the multi-carrier TDMA communication system, not only time but also frequency is used, so that a great deal of connectivity is provided. It becomes possible.
【０００２】一方衛星通信では降雨により信号が減衰し
信号対雑音比が劣化する。特にＫｕ，Ｋａ帯の高い周波
数で減衰が大となる。この様な問題を解決するため送信
電力制御が導入される。送信電力の制御方法は各種ある
が、何等かの手段により降雨による伝送路の減衰量を知
り、この減衰量を補正する様送信電力を増大し、常に衛
星中継器への到達電力が一定となる様に制御するもので
ある。降雨減衰量を知る手段としては衛星経由で折り返
し受信される信号のＣ／Ｎを測定することで得られる。On the other hand, in satellite communication, a signal is attenuated by rainfall, and a signal-to-noise ratio is deteriorated. In particular, the attenuation is large at high frequencies in the Ku and Ka bands. Transmission power control is introduced to solve such a problem. There are various methods for controlling the transmission power. The transmission power is increased by knowing the attenuation of the transmission line due to rainfall by some means, and the transmission power is increased so as to correct the attenuation, so that the power reaching the satellite repeater is always constant. Control. Means for knowing the amount of rain attenuation can be obtained by measuring the C / N of a signal returned and received via a satellite.
【０００３】したがって、マルチキャリアＴＤＭＡ方式
でこの様なＣ／Ｎを測定するために多数のキャリアに対
して簡単に精度良く計測できる方法が強く望まれてい
る。Therefore, in order to measure such C / N in the multi-carrier TDMA system, there is a strong demand for a method capable of easily and accurately measuring a large number of carriers.
【０００４】[0004]
【従来の技術】単一キャリアの場合のＣ／Ｎの計測方法
としては、信号を検波し、この検波電圧の平均値と分散
から求める方法が知られている。すなわち、検波電圧の
平均値が信号レベルを表わし、検波電圧のバラツキが雑
音レベルを表わすことになるので、両者の比をとること
によって信号対雑音比（Ｃ／Ｎ）を計測することができ
る。2. Description of the Related Art As a method of measuring C / N in the case of a single carrier, there is known a method of detecting a signal and obtaining the signal from the average value and variance of the detected voltage. That is, since the average value of the detection voltage represents the signal level, and the variation of the detection voltage represents the noise level, the signal-to-noise ratio (C / N) can be measured by taking the ratio between the two.
【０００５】この方式をマルチキャリアの場合にそのま
ま適用するとすれば、図３の様な構成が考えられる。帯
域フィルタ１０は入力信号から周波数ｆ1 〜ｆn の各キ
ャリア成分を抽出するもので、それらの出力は検波器１
２０においてそれぞれ検波され、その検波出力にもとづ
き、Ｃ／Ｎ検出部１４０において各キャリア毎に前述の
方法に従ってＣ／Ｎが算出され、加算部１６０において
それらの総和がとられ、除算部１６２においてキャリア
数で除算することによって、各キャリア毎に算出された
Ｃ／Ｎの平均値が算出される。If this method is applied as it is to a multi-carrier case, a configuration as shown in FIG. 3 can be considered. Band filter 10 extracts a respective carrier component of the frequency f 1 ~f n from the input signal, the outputs of the detector 1
20, the C / N detection section 140 calculates the C / N for each carrier in accordance with the above-described method based on the detection output, the addition section 160 calculates the sum of the C / N, and the division section 162 calculates the C / N. By dividing by a number, an average value of C / N calculated for each carrier is calculated.
【０００６】[0006]
【発明が解決しようとする課題】前述の方式では、キャ
リア毎にＣ／Ｎを算出してさらに平均化処理を施すため
に回路規模が非常に増大するという問題がある。また、
マルチキャリア方式の場合には衛星に内蔵される１台の
中継器ですべてのキャリアについての増幅を行なうの
で、その非直線性のためにインターモジュレーション
（ＩＭ）雑音を生じるが、前述の方式によれば、このＩ
Ｍ雑音と降雨等による雑音の区別がつかず、そのため送
信電力制御が発散する恐れがあるという問題もある。The above-mentioned method has a problem that the circuit scale is extremely increased because the C / N is calculated for each carrier and the averaging process is performed. Also,
In the case of the multi-carrier system, since all carriers are amplified by a single repeater built in the satellite, intermodulation (IM) noise is generated due to the non-linearity. If I
There is also a problem that the M noise and the noise due to rainfall cannot be distinguished, so that the transmission power control may diverge.
【０００７】したがって本発明の目的は、比較的簡潔な
構成であり、かつＩＭ雑音に影響されることなくＣ／Ｎ
を見積ることのできるＣ／Ｎ測定装置を提供することに
ある。[0007] It is therefore an object of the present invention to provide a relatively simple configuration and a C / N ratio that is not affected by IM noise.
It is an object of the present invention to provide a C / N measuring device capable of estimating the C / N.
【０００８】[0008]
【課題を解決するための手段】図１は本発明の原理構成
を表わす図である。入力信号は中心周波数が異なる複数
の帯域フィルタ１０により、所定の周波数ｆ1 〜ｆn の
キャリア成分に分けられ、それぞれ複数の受信レベル計
測手段１２によってそれらの受信レベルＣ1 〜Ｃn が計
測される。Ｃ／Ｎ計測手段１４はその中の特定のキャリ
アｆ1 についてＣ／Ｎの計測を行なう。補正値算出手段
２０は受信レベル計測手段１２が計測した特定のキャリ
アの受信レベルＣ1 とそれ以外のキャリアの受信レベル
Ｃ2 〜Ｃn とのレベル差の平均値を算出し、それからＣ
／Ｎ補正値γを算出する。Ｃ／Ｎ補正手段２２はＣ／Ｎ
計測手段１４が計測したＣ／ＮすなわちＣ1 ／Ｎ1 を該
Ｃ／Ｎ補正値γによって補正して出力する。FIG. 1 is a diagram showing the principle configuration of the present invention. The input signals a plurality of band filter 10 is different center frequencies is divided into carrier components in a predetermined frequency f 1 ~f n, it is respectively measured their reception level C 1 -C n by a plurality of reception level measuring unit 12 You. C / N measuring means 14 performs the measurement of C / N for a particular carrier f 1 therein. The correction value calculation means 20 calculates the average value of the level difference between the reception level C 1 of the specific carrier measured by the reception level measurement means 12 and the reception levels C 2 to C n of the other carriers, and then calculates C
/ N correction value γ is calculated. The C / N correction means 22 is C / N
The C / N measured by the measuring means 14, that is, C 1 / N 1 is corrected by the C / N correction value γ and output.
【０００９】前記の特定のキャリアとしては、ＩＭ雑音
の影響を受けないかまたは最も影響の小さいキャリアを
予め選択することが望ましい。As the specific carrier, it is desirable to previously select a carrier which is not affected by the IM noise or has the least influence.
【００１０】[0010]
【作用】各キャリア毎にＣ／Ｎを計測する必要がないの
で回路規模が小さくなる。また、ＩＭ雑音の影響の程度
はキャリア周波数から予め予測することができるので、
その影響を受けないかまたは影響の最も小さいキャリア
を選択することができ、それについてのみＣ／Ｎ計測を
行なうことで、ＩＭ雑音に影響されずにＣ／Ｎを見積る
ことが可能となる。Since the C / N need not be measured for each carrier, the circuit scale is reduced. Also, since the degree of the influence of the IM noise can be predicted in advance from the carrier frequency,
A carrier that is not affected or has the least effect can be selected, and C / N measurement is performed only on the carrier, so that C / N can be estimated without being affected by IM noise.
【００１１】[0011]
【実施例】図２は本発明に係るＣ／Ｎ測定装置の一実施
例を表わすブロック図である。図３と同一の構成要素に
は同一の参照番号を付して、その説明を省略する。ＩＭ
雑音は各キャリアの周波数の整数倍の差の周波数で発生
するものであるから、ＩＭ雑音の影響の程度は予め予測
することができる。したがって、Ｃ／Ｎ計測部１４２に
おいてＣ／Ｎ計測が行なわれるキャリアｆ1 としては、
その影響を受けないかまたは最も小さいキャリアを選ぶ
ものとする。FIG. 2 is a block diagram showing an embodiment of the C / N measuring apparatus according to the present invention. The same components as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. IM
Since noise occurs at a frequency that is an integer multiple of the frequency of each carrier, the degree of the influence of IM noise can be predicted in advance. Therefore, as carrier f 1 on which C / N measurement is performed in C / N measurement section 142,
The carrier that is not affected or has the smallest carrier shall be selected.
【００１２】補正値算出部２００は、以下に詳述する様
に各キャリアについての検波出力から補正値γを算出
し、乗算部２２０はキャリアｆ1 について計測されたＣ
／Ｎに補正値γを乗算して帯域全体についてのＣ／Ｎと
して出力する。キャリアｆ1 の検波出力すなわちキャリ
ア電力Ｃ1 とキャリアｆ2 〜ｆn のキャリア電力Ｃ2 〜
Ｃn との電力値の差の平均値△ＣをThe correction value calculation section 200 calculates a correction value γ from the detection output of each carrier as described in detail below, and the multiplication section 220 calculates the C value measured for the carrier f 1.
/ N is multiplied by the correction value γ and output as C / N for the entire band. Detection output or carrier power of the carrier f 1 C 1 and the carrier f 2 ~f n carrier power C 2 ~ of
The average value △ C of the difference between the power value and C n
【００１３】[0013]
【数１】 とすると、Ｃ／Ｎ補正量γは γ＝１＋△Ｃ／Ｃ1 （１） で表わされる。したがって、ｆ1 において測定したＣ／
ＮをＣ1 ／Ｎ1 とすると、補正後のＣ／Ｎは Ｃ／Ｎ＝（Ｃ1 ／Ｎ1 ）×γ （２） ＝（Ｃ1 ／Ｎ1 ）（１＋△Ｃ／Ｃ1 ） となる。したがって補正値算出部２００において（１）
式の計算を行なって補正値γを算出し、乗算部２２０に
おいて、（２）式に基づいてＣ1 ／Ｎ1 に乗算すること
により、補正されたＣ／Ｎが算出される。(Equation 1) Then, the C / N correction amount γ is represented by γ = 1 + △ C / C 1 (1). Thus, C was measured at f 1 /
If N is C 1 / N 1 , the corrected C / N is C / N = (C 1 / N 1 ) × γ (2) = (C 1 / N 1 ) (1 + △ C / C 1 ) Become. Therefore, in the correction value calculation unit 200, (1)
The correction value γ is calculated by calculating the equation, and the multiplied section 220 multiplies C 1 / N 1 based on the equation (2) to calculate the corrected C / N.
【００１４】[0014]
【発明の効果】以上述べてきたように本発明によれば、
予め定められたＩＭ雑音の影響を受けないキャリアにつ
いてのみＣ／Ｎ計測を行ない、各キャリアの受信レベル
に基づいて補正を行なうことによって、比較的簡潔な構
成で、ＩＭ雑音の影響を受けないＣ／Ｎ計測を行なうこ
とが可能となり、適切な送信電力制御が可能となる。As described above, according to the present invention,
C / N measurement is performed only on carriers that are not affected by predetermined IM noise, and correction is performed based on the reception level of each carrier. / N measurement can be performed, and appropriate transmission power control can be performed.
【図１】本発明の原理図である。FIG. 1 is a principle diagram of the present invention.
【図２】本発明の一実施例を表わす図である。FIG. 2 is a diagram illustrating an embodiment of the present invention.
【図３】従来技術による構成を表わす図である。FIG. 3 is a diagram showing a configuration according to a conventional technique.
１０…帯域フィルタ、 １２…受信レベル計測手段、 １４…Ｃ／Ｎ計測手段、 ２０…補正値算出手段、 ２２…Ｃ／Ｎ補正手段。 DESCRIPTION OF SYMBOLS 10 ... Band filter, 12 ... Reception level measuring means, 14 ... C / N measuring means, 20 ... Correction value calculating means, 22 ... C / N correcting means.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小野 隆 東京都千代田区内幸町１丁目１番６号 日本電信電話株式会社内 (72)発明者 正村 達郎 東京都千代田区内幸町１丁目１番６号 日本電信電話株式会社内 (56)参考文献 特開 平３−101446（ＪＰ，Ａ) 特表 昭62−502932（ＪＰ，Ａ) 1990年電子情報通信学会春季全国大会 講演論文集，1990年３月15日，分冊２, Ｂ−230 (58)調査した分野(Int.Cl.7，ＤＢ名) H04J 1/00 - 1/20 H04J 11/00 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Takashi Ono 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Tatsuro Masamura 1-16-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-3-101446 (JP, A) Tokuhyo Sho 62-502932 (JP, A) 1990 IEICE Spring National Convention Proceedings, March 1990 15th, Volume 2, B-230 (58) Fields investigated (Int. Cl. 7 , DB name) H04J 1/00-1/20 H04J 11/00
Claims (1)
するマルチキャリア通信方式に適したＣ／Ｎ測定装置で
あって、 該帯域内の特定の一搬送波の受信Ｃ／Ｎを計測するＣ／
Ｎ計測手段（１４）と、 該帯域内の各搬送波の受信レベルをそれぞれ計測する複
数の受信レベル計測手段（１２）と、 該受信レベル計測手段（１２）が計測した該特定の搬送
波の受信レベルと該特定の搬送波以外の搬送波の受信レ
ベルのレベル差の平均値からＣ／Ｎ補正値を算出する補
正値算出手段（２０）と、 該Ｃ／Ｎ補正値により該Ｃ／Ｎ計測手段（１４）が計測
したＣ／Ｎを補正するＣ／Ｎ補正手段（２２）を具備す
ることを特徴とするＣ／Ｎ測定装置。1. A C / N measuring apparatus suitable for a multi-carrier communication system in which one band is divided into a plurality of carriers and used, wherein a reception C / N of a specific one carrier in the band is measured. C /
N measurement means (14); a plurality of reception level measurement means (12) for measuring the reception level of each carrier in the band; and the reception level of the specific carrier measured by the reception level measurement means (12) And a correction value calculating means (20) for calculating a C / N correction value from an average value of level differences between reception levels of carriers other than the specific carrier, and a C / N measuring means (14) based on the C / N correction value. C) a C / N measuring device comprising a C / N correcting means (22) for correcting the measured C / N.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19988792A JP3186847B2 (en) | 1992-07-27 | 1992-07-27 | C / N measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19988792A JP3186847B2 (en) | 1992-07-27 | 1992-07-27 | C / N measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0646013A JPH0646013A (en) | 1994-02-18 |
| JP3186847B2 true JP3186847B2 (en) | 2001-07-11 |
Family
ID=16415264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19988792A Expired - Fee Related JP3186847B2 (en) | 1992-07-27 | 1992-07-27 | C / N measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3186847B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8247481B2 (en) | 2008-10-27 | 2012-08-21 | Jsr Corporation | Photosensitive insulating resin composition, cured product thereof and ABA block copolymer |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100758767B1 (en) * | 2001-04-06 | 2007-09-14 | 엘지노텔 주식회사 | Wire interference signal judgement apparatus and method |
| JP4842506B2 (en) * | 2003-09-12 | 2011-12-21 | マスプロ電工株式会社 | Signal level measuring device |
| JP6415476B2 (en) * | 2016-05-02 | 2018-10-31 | 日本電信電話株式会社 | Signal quality estimation method and signal quality estimation apparatus |
-
1992
- 1992-07-27 JP JP19988792A patent/JP3186847B2/en not_active Expired - Fee Related
Non-Patent Citations (1)
| Title |
|---|
| １９９０年電子情報通信学会春季全国大会講演論文集，１９９０年３月１５日，分冊２，Ｂ−２３０ |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8247481B2 (en) | 2008-10-27 | 2012-08-21 | Jsr Corporation | Photosensitive insulating resin composition, cured product thereof and ABA block copolymer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0646013A (en) | 1994-02-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6701264B2 (en) | Method of and apparatus for calibrating receive path gain | |
| KR100238372B1 (en) | Receiver having frequency deviation evaluation device | |
| US5731993A (en) | Nonlinear amplifier operating point determination system and method | |
| JPH0555976A (en) | Receiver for mobile telephone system | |
| US4570127A (en) | Automatic gain control circuit for burst signal communication system | |
| JPH0342925A (en) | Receiver for mobile telephone | |
| RU2373660C2 (en) | Coherent tracking for frequency-modulated receiver of wpd with help of antenna system with switched diversity | |
| JP3186847B2 (en) | C / N measuring device | |
| US7295157B2 (en) | Array antenna receiver device | |
| EP0519487B1 (en) | Transmission power control method and apparatus in satellite communication | |
| JP6650580B2 (en) | CN ratio detection circuit and reception circuit | |
| HUT74332A (en) | Receiver path selection in time devision multiple access receivers | |
| CA2155432C (en) | Circuit for removing random fm noise | |
| EP0687080A1 (en) | Receive signal level detection system | |
| JP2965821B2 (en) | Wireless relay device | |
| JPH0923125A (en) | Automatic gain control circuit for linearly modulated wave | |
| JP2652955B2 (en) | Adaptive tilt beam diversity transmission / reception method | |
| JPH0414335A (en) | Gain control circuit for time division multiplex communication | |
| JP3155051B2 (en) | Transmission power control method | |
| JP2000068939A (en) | Optical modulation rate setting method and its circuit for electrooptic converter | |
| JP2526057B2 (en) | Mobile radio with frequency stabilization function | |
| JP2562858B2 (en) | Transmission power control device | |
| JP3105825B2 (en) | Automatic gain control circuit | |
| JP2792292B2 (en) | Receiving machine | |
| JPH05284071A (en) | Transmission power control system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20010327 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080511 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090511 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090511 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100511 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100511 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110511 Year of fee payment: 10 |
|
| LAPS | Cancellation because of no payment of annual fees |