JPH07312590A - Method for selecting antenna of diversity - Google Patents
Method for selecting antenna of diversityInfo
- Publication number
- JPH07312590A JPH07312590A JP6127058A JP12705894A JPH07312590A JP H07312590 A JPH07312590 A JP H07312590A JP 6127058 A JP6127058 A JP 6127058A JP 12705894 A JP12705894 A JP 12705894A JP H07312590 A JPH07312590 A JP H07312590A
- Authority
- JP
- Japan
- Prior art keywords
- antenna
- reception
- reception level
- time
- transmission
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ＴＤＤ方式（時分割方
式）の通信機におけるダイバシティのアンテ選択方法に
関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diversity antenna selection method in a TDD (time division) communication device.
【０００２】[0002]
【従来技術】陸上移動体通信における電波の伝搬特性は
周囲の建物や地形による反射や散乱波により伝搬経路の
異なる多数の波が到来し、互いに干渉し複雑な定在波を
生じる。このとき移動局受信波の包絡線と位相はランダ
ムに変動し、激しいフェ−ジングとなって現れる。この
電解強度分布はレイリ分布に近似されレイリ−フェ−ジ
ングと云われる。2. Description of the Related Art Regarding the propagation characteristics of radio waves in land mobile communications, a large number of waves having different propagation paths arrive due to reflected or scattered waves from surrounding buildings or topography, and interfere with each other to generate complex standing waves. At this time, the envelope and the phase of the received wave of the mobile station randomly fluctuate and appear as severe fading. This electrolytic intensity distribution is approximated to the Rayleigh distribution and is called Rayleigh-fading.
【０００３】上記フェ−ジングの影響を軽減するために
従来よりダイバ−シティ受信が採用されている。これは
複数のアンテナを使用しフェ−ジングの変動が互いに相
関の少ない電波を受信し、受信レベルの高い受信波を選
択する方法である。最近のデジタル通信におけるＴＤＤ
方式では送受信は送信スロット及び受信スロットで時分
割され交信される。このＴＤＤ方式でのダイバ−シティ
受信は受信スロットで複数のアンテナで受信した内で受
信レベルの最も高いアンテナを選択して受信し、送信は
そのアンテナで次の送信スロットで送信を行っている。
受信レベルの高いアンテナはフェ−ジングの影響が少な
く、従って送信時もそのアンテナを使用すれば高利得が
得られるからである。To reduce the influence of fading, diversity reception has been conventionally used. This is a method in which a plurality of antennas are used to receive radio waves whose fading fluctuations have little correlation with each other and select a received wave with a high reception level. Recent TDD in digital communication
In the method, transmission and reception are time-divisionally communicated in a transmission slot and a reception slot. In diversity reception in this TDD system, the antenna with the highest reception level is selected and received among a plurality of antennas received in a reception slot, and transmission is performed in the next transmission slot with that antenna.
This is because an antenna with a high reception level is less affected by fading, so that high gain can be obtained by using that antenna even during transmission.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、図１に
示すようにアンテナ１の受信レベルａ及びアンテナ２の
受信レベルｂが変化する場合、受信時刻ｔ3の受信スロ
ットで受信した場合はアンテナ１の受信レベルＬ13はア
ンテナ２の受信レベルＬ23より高くアンテナ１が選択さ
れ受信されるが、送信時刻ｔ4ではアンテナ１の受信レ
ベルＬ14がアンテナ２の受信レベルＬ24より低いにも関
わらずアンテナ１で送信してしまうと云う問題があっ
た。However, when the reception level a of the antenna 1 and the reception level b of the antenna 2 change as shown in FIG. 1, when the reception level of the antenna 1 is received at the reception slot at the reception time t 3 . The reception level L 13 is higher than the reception level L 23 of the antenna 2 and the antenna 1 is selected and received, but at the transmission time t 4 , the reception level L 14 of the antenna 1 is lower than the reception level L 24 of the antenna 2 There was a problem of transmitting with the antenna 1.
【０００５】本発明は上述の点に鑑みてなされたもの
で、上記問題点を除去するために、各アンテナの受信レ
ベルの変化から送信時刻の各アンテナの受信レベルを予
測し、予測した受信レベルの高いアンテナを選択し送信
するダイバシティのアンテナ選択方法を提供することを
目的とする。The present invention has been made in view of the above points, and in order to eliminate the above problems, the reception level of each antenna at the transmission time is predicted from the change in the reception level of each antenna, and the predicted reception level is obtained. It is an object of the present invention to provide a diversity antenna selection method for selecting and transmitting an antenna with high frequency.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決するため
本発明は、複数のアンテナ、受信レベル検出器及びアン
テナ切替器を具備し、ＴＤＤ方式で送受信を行う通信機
におけるダイバシティのアンテナ選択方法において、図
２に示すように前記通信機に受信レベルのデ−タを記憶
するメモリ５を設け、前記受信レベル検出器３は前記複
数の各アンテナ毎に受信スロット時刻における受信レベ
ルを検出し、そのデ−タを前記メモリ５に時系列に蓄積
し、ＣＰＵ８は前記時系列に蓄積されたデ−タから次の
送信スロット時刻における受信レベルを予測し、次の送
信スロット時刻には前記予測した受信レベルの最も高い
アンテナを選択し送信することを特徴とする。In order to solve the above-mentioned problems, the present invention provides a diversity antenna selection method in a communication device which comprises a plurality of antennas, a reception level detector and an antenna switch, and which performs transmission and reception in the TDD system. As shown in FIG. 2, the communication device is provided with a memory 5 for storing reception level data, and the reception level detector 3 detects the reception level at the reception slot time for each of the plurality of antennas. The data is accumulated in the memory 5 in time series, and the CPU 8 predicts the reception level at the next transmission slot time from the data accumulated in time series, and the predicted reception at the next transmission slot time. The feature is that the antenna with the highest level is selected and transmitted.
【０００７】[0007]
【作用】本発明では、前記受信レベル検出器３は各アン
テナの受信レベルのデ−タをメモリ５へ時系列に蓄積
し、前記アンテナ切替器４は時系列に蓄積されたデ−タ
から、次の送信スロット時刻における受信レベルを予測
し、送信時には予測した受信レベルの最も高いアンテナ
を選択し送信するので、従来のように送信時にレベルの
低いアンテナで送信することは少なくなり、ダイバシテ
ィのゲインを上げることができる。In the present invention, the reception level detector 3 stores the reception level data of each antenna in the memory 5 in time series, and the antenna switching unit 4 stores the data in time series. Since the reception level at the next transmission slot time is predicted and the antenna with the highest predicted reception level is selected and transmitted at the time of transmission, it is less likely to transmit with a low level antenna at the time of transmission as in the past, and diversity gain is reduced. Can be raised.
【０００８】[0008]
【実施例】以下本発明の一実施例を図面に基づいて詳細
に説明する。図２は本発明のダイバ−シティのアンテナ
選択方法を採用したアナログ通信方式の通信機の構成例
を示す図である。図示するように本発明のダイバ−シテ
ィのアンテナ選択方法を採用したアナログ通信方式の通
信機はアンテナ１、アンテナ２、受信レベル検出器３、
アンテナ切替器４、メモリ５、送受信機６、送受話器
７、ＣＰＵ８等で構成される。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 2 is a diagram showing a configuration example of a communication device of an analog communication system adopting the diversity antenna selection method of the present invention. As shown in the figure, the analog communication type communication device adopting the diversity antenna selection method of the present invention includes an antenna 1, an antenna 2, a reception level detector 3,
The antenna switching device 4, the memory 5, the transceiver 6, the handset 7 and the CPU 8 are included.
【０００９】アンテナ１とアンテナ２は互いに相関関係
の少ない離れた位置に設置され、各アンテナの受信信号
はそれぞれアンテナ切替器４を介して送受信機６内の受
信部６−３にはアンテナ１の受信信号が、受信部６−４
にはアンテナ２の受信信号が入力され、それぞれ高周波
増幅されて、受信アンテナ選択部６−５を介して復調部
６−６に入力されると共に直接受信レベル検出器３に入
力される。受信レベル検出器３は各アンテナの受信スロ
ット時刻における受信レベルを検出しそのデ−タをＣＰ
Ｕ８へ送る。The antenna 1 and the antenna 2 are installed at positions apart from each other with little correlation with each other, and the received signals of the respective antennas are transmitted to the receiving section 6-3 in the transmitter / receiver 6 via the antenna switching unit 4 and are transmitted to the receiving unit 6-3. The received signal is received by the receiving unit 6-4
The received signal of the antenna 2 is input to the receiver, is subjected to high frequency amplification, is input to the demodulation unit 6-6 via the receiving antenna selection unit 6-5, and is directly input to the reception level detector 3. The reception level detector 3 detects the reception level at the reception slot time of each antenna and outputs the data as CP.
Send to U8.
【００１０】ＣＰＵ８はそのデ−タをメモリ５へ蓄積し
そのデ−タから次の送信スロット時刻で最も受信レベル
の高いアンテナを予測し（詳細は後述）、送信スロット
時にアンテナ切替器４を送信アンテナ選択信号で制御し
予測したそのアンテナ（１又は２）を接続させる。ＣＰ
Ｕ８は送信アンテナ選択信号の値に送受信切替信号を送
受信のスロット切替タイミングでアンテナ切替器４へ送
る。送受信切替信号によって受信状態にされたアンテナ
切替器４は、アンテナ１、アンテナ２の両アンテナを送
受信機６へ接続する。また、ＣＰＵ８はメモリ５へ蓄積
したデータから次の受信スロット時刻で最も受信レベル
の高いアンテナ（１又は２）を前述の送信スロット時刻
での予測と同様の方法で予測し、受信スロット時に受信
アンテナ選択信号で送受信機６内の受信アンテナ選択部
６−５を制御する。The CPU 8 stores the data in the memory 5, predicts the antenna with the highest reception level at the next transmission slot time from the data (details will be described later), and transmits the antenna switch 4 at the transmission slot. The antenna (1 or 2) controlled and predicted by the antenna selection signal is connected. CP
U8 sends the transmission / reception switching signal to the value of the transmission antenna selection signal to the antenna switching unit 4 at the transmission / reception slot switching timing. The antenna switch 4 which is set to the reception state by the transmission / reception switching signal connects both the antenna 1 and the antenna 2 to the transceiver 6. Further, the CPU 8 predicts the antenna (1 or 2) having the highest reception level at the next reception slot time from the data stored in the memory 5 by the same method as the above-mentioned prediction at the transmission slot time, and the reception antenna at the reception slot time. The reception antenna selection unit 6-5 in the transceiver 6 is controlled by the selection signal.
【００１１】これによって送受信機６は受信時には最も
受信レベルの高いアンテナからの受信信号を復調し送受
話器７へ音声出力し、送信時には送受話器７からの音声
信号を変調部６−１で変調し、送信部６−２及びアンテ
ナ切替器４を通して最も受信レベルの高いアンテナ（１
又は２）から送信する。As a result, the transceiver 6 demodulates the received signal from the antenna having the highest reception level at the time of reception and outputs the voice to the handset 7. At the time of transmission, the voice signal from the handset 7 is modulated by the modulator 6-1. , The antenna having the highest reception level (1
Or send from 2).
【００１２】図１は本発明のダイバ−シティのアンテナ
選択方法を説明する図である。通信機は図１に示すよう
に時分割方式で時刻ｔ1、ｔ3・・・の受信スロット、時
刻ｔ2、ｔ4・・・の送信スロットを交互に繰り返し通信
を行う。ＣＰＵ８は受信レベル検出器３で時刻ｔ1、ｔ3
・・・で受信したアンテナ１の受信レベルＬ11、Ｌ13・
・・及び、アンテナ２の受信レベルＬ21、Ｌ23・・・の
各デ−タをメモリ５へ蓄積する。FIG. 1 is a diagram for explaining a diversity antenna selection method according to the present invention. As shown in FIG. 1, the communicator alternately repeats communication in a time division manner with reception slots at times t 1 , t 3 ... And transmission slots at times t 2 , t 4 . The CPU 8 uses the reception level detector 3 at times t 1 and t 3
The reception levels L 11 , L 13 of the antenna 1 received at.
.. and each data of the reception levels L 21 , L 23 ... Of the antenna 2 is stored in the memory 5.
【００１３】更に、ＣＰＵ８はメモリ５へ蓄積されたデ
−タから次の送信スロット時刻のアンテナ１の受信レベ
ルとアンテナ２の受信レベルを予測する。例えば時刻ｔ
3で信号を受信した時点でアンテナ切替器４はアンテナ
１の受信レベルＬ11、Ｌ13から次の送信スロット時刻ｔ
4における受信レベルＬ14と、アンテナ２の受信レベル
Ｌ21、Ｌ23から次の送信スロット時刻ｔ4における受信
レベルＬ24を予測し、予測した受信レベルの高いアンテ
ナ（図１の例ではアンテナ２）へ接続を切替送信を行
う。予測計算方法の一例として述べると、受信レベルＬ
11、Ｌ13・・・のデ−タから一次近似又は、二次近似曲
線を求めその延長線上で送信スロット時刻ｔ4の受信レ
ベルＬ14を求め、同様にして受信レベルＬ21、Ｌ23・・
・から受信レベルＬ24を求める。Further, the CPU 8 predicts the reception level of the antenna 1 and the reception level of the antenna 2 at the next transmission slot time from the data stored in the memory 5. For example, time t
At the time of receiving the signal at 3 , the antenna switching unit 4 determines from the reception levels L 11 and L 13 of the antenna 1 to the next transmission slot time t.
The reception level L 24 at the next transmission slot time t 4 is predicted from the reception level L 14 at 4 and the reception levels L 21 and L 23 at the antenna 2, and the predicted high reception level antenna (the antenna 2 in the example of FIG. 1 is used. ) Switch the connection to and send. As an example of the predictive calculation method, the reception level L
A first-order approximation curve or a second-order approximation curve is obtained from the data of 11 , L 13 ... And a reception level L 14 at the transmission slot time t 4 is obtained on the extension line thereof, and similarly, reception levels L 21 , L 23.・
・ The reception level L 24 is calculated from.
【００１４】図３は本発明のダイバーシティのアンテナ
選択方式を採用したデジタル通信方式の通信機の構成例
を示す図である。本実施例ではアンテナ１の受信信号の
受信部６−３に復調部６−６を接続し、アンテナ２の受
信信号の受信部６−４に復調部６−７を接続し、これら
復調部６−６，６−７からの出力をそれぞれ受信アンテ
ナ選択部６−５とビット誤り発生率検出器９に入力す
る。FIG. 3 is a diagram showing a configuration example of a digital communication type communication device adopting the diversity antenna selection method of the present invention. In this embodiment, the demodulation unit 6-6 is connected to the reception unit 6-3 of the reception signal of the antenna 1, the demodulation unit 6-7 is connected to the reception unit 6-4 of the reception signal of the antenna 2, and these demodulation units 6 and 6 are connected. The outputs from -6 and 6-7 are input to the receiving antenna selector 6-5 and the bit error rate detector 9, respectively.
【００１５】送信スロット時刻に選択するアンテナは、
ＣＰＵ８が図２の実施例と同様に受信レベル検出器３で
検出し、メモリ５に時系列に蓄積されたデータから予測
してアンテナ切替制御を行う。受信スロット時刻に選択
するアンテナは、メモリ５に時系列に蓄積したアンテナ
１、アンテナ２の受信レベルとビット誤り発生率検出器
９の出力であるアンテナ１、アンテナ２の受信信号のビ
ット誤り発生率とから受信信号の品質が最も良いアンテ
ナを予測する。ビット誤り発生率は受信信号に含まれる
チェックコードから判定する。The antenna selected at the transmission slot time is
Similar to the embodiment of FIG. 2, the CPU 8 detects the reception level detector 3 and predicts from the data accumulated in the memory 5 in time series to perform antenna switching control. The antennas selected at the reception slot time are the reception levels of the antennas 1 and 2 accumulated in time series in the memory 5 and the bit error occurrence rates of the reception signals of the antennas 1 and 2 output from the bit error occurrence rate detector 9. From this, the antenna with the best received signal quality is predicted. The bit error rate is determined from the check code included in the received signal.
【００１６】ＣＰＵ８はメモリ５にそれぞれ時系列に蓄
積したアンテナ１、アンテナ２の受信レベルとビット誤
り発生率について、次の受信スロット時刻での値を予測
し、予測した受信レベルとビット誤り発生率とを判定要
素とする判定基準に従い受信スロット時刻で受信信号の
品質が最良となるアンテナを予測する。ＣＰＵ８がこの
予測結果に基づき受信スロットの切替タイミングで受信
アンテナ選択信号を出力し、受信アンテナ選択部６−５
を制御すると接続された復調部（６−６又は６−７）の
出力が受信アンテナ選択部６−５を介して復号化部６−
９に入力される。The CPU 8 predicts the value at the next reception slot time for the reception level and the bit error occurrence rate of the antenna 1 and the antenna 2 stored in the memory 5 in time series, and predicts the predicted reception level and the bit error occurrence rate. According to the determination criteria with and as the determination factors, the antenna with the best received signal quality at the reception slot time is predicted. Based on this prediction result, the CPU 8 outputs the reception antenna selection signal at the reception slot switching timing, and the reception antenna selection unit 6-5
Control of the output of the connected demodulation unit (6-6 or 6-7) to the decoding unit 6- via the reception antenna selection unit 6-5.
9 is input.
【００１７】これによって、通信機は受信時にも最も受
信品質の良いアンテナからの受信信号を復調並びに復合
化し送受話器７からの音声信号を符号化部６−８で符号
化し、更に変調部６−１で変調し、送信部６−２及びア
ンテナ切替器４を通して最も受信レベルの高いアンテナ
１又はアンテナ２から送信する。As a result, the communication device demodulates and decodes the reception signal from the antenna having the best reception quality at the time of reception, encodes the voice signal from the handset 7 by the encoding unit 6-8, and further the modulation unit 6-. 1, and the signal is transmitted from the antenna 1 or the antenna 2 having the highest reception level through the transmitting unit 6-2 and the antenna switch 4.
【００１８】上述したように時系列に蓄積されたデ−タ
から次の送信スロット時刻における受信レベルを予測
し、送信時には予測した受信レベルの最も高いアンテナ
を選択し送信するので、従来のように送信時にレベルの
低いアンテナで送信することは少なくなる。As described above, the reception level at the next transmission slot time is predicted from the data accumulated in time series, and at the time of transmission, the antenna with the highest predicted reception level is selected and transmitted. It is less likely that a low level antenna will be used for transmission.
【００１９】[0019]
【発明の効果】以上、詳細に説明したように本発明によ
れば、アンテナ選択切替手段は各アンテナの受信レベル
のデ−タを時系列に蓄積し、時系列に蓄積されたデ−タ
から次の送信スロット時刻における受信レベルを予測
し、送信時には最も受信レベルの高いアンテナを選択し
送信するので、従来のように送信時にレベルの低いアン
テナで送信することはなくなり、ダイバシティのゲイン
を上げることができるという優れた効果が得られる。As described above in detail, according to the present invention, the antenna selection switching means accumulates the reception level data of each antenna in time series, and the data is accumulated from the time series. The reception level at the time of the next transmission slot is predicted, and the antenna with the highest reception level is selected and transmitted at the time of transmission.Therefore, it is not necessary to transmit with the antenna with the low level at the time of transmission as in the past, and diversity gain should be increased. The excellent effect of being able to do is obtained.
【図１】本発明のダイバ−シティのアンテナ選択方法を
説明する図である。FIG. 1 is a diagram illustrating a diversity antenna selection method of the present invention.
【図２】本発明のダイバ−シティのアンテナ選択方法を
採用したアナログ通信方式の通信機の構成例を示す図で
ある。FIG. 2 is a diagram showing a configuration example of a communication device of an analog communication system adopting the diversity antenna selection method of the present invention.
【図３】本発明のダイバ−シティのアンテナ選択方法を
採用したデジタル通信方式の通信機の構成例を示す図で
ある。FIG. 3 is a diagram showing a configuration example of a communication device of a digital communication system adopting the diversity antenna selection method of the present invention.
【符号の説明】 １ アンテナ ２ アンテナ ３ 受信レベル検出器 ４ アンテナ切替器 ５ メモリ ６ 送受信機 ７ 送受話器 ６−１ 変調部 ６−２ 送信部 ６−３ 受信部 ６−４ 受信部 ６−５ 受信アンテナ選択部 ６−６ 復調部 ６−７ 復調部 ６−８ 符号化部 ６−９ 復号化部 ７ 送受話機 ８ ＣＰＵ ９ ビット誤り発生率検出器[Explanation of Codes] 1 antenna 2 antenna 3 reception level detector 4 antenna switcher 5 memory 6 transceiver 7 transmitter / receiver 6-1 modulator 6-2 transmitter 6-3 receiver 6-4 receiver 6-5 reception Antenna selection unit 6-6 Demodulation unit 6-7 Demodulation unit 6-8 Encoding unit 6-9 Decoding unit 7 Handset 8 CPU 9 Bit error rate detector
Claims (1)
びアンテナ切替手段を具備し、時分割方式で送受信を行
う通信機におけるダイバシティのアンテナ選択方法にお
いて、 前記通信機に受信レベルのデ−タを記憶する記憶手段を
設け、 前記受信レベル検出手段は前記複数の各アンテナ毎に受
信スロットにおける受信レベルを検出し、そのデ−タを
前記記憶手段に時系列に蓄積し、 更に、前記時系列に蓄積されたデ−タから次の送信スロ
ットにおける受信レベルを予測する予測手段を設け、 送信スロットには前記アンテナ切替手段は前記予測した
受信レベルの最も高いアンテナを選択し送信することを
特徴とするダイバシティのアンテナ選択方法。1. A diversity antenna selecting method in a communication device, comprising a plurality of antennas, a reception level detecting means, and an antenna switching means, and transmitting and receiving in a time division system, wherein data of the reception level is stored in the communication device. The receiving level detecting means detects the receiving level in the receiving slot for each of the plurality of antennas, accumulates the data in the storing means in time series, and further accumulates in the time series. Diversity characterized in that a prediction means for predicting a reception level in the next transmission slot is provided from the received data, and the antenna switching means selects and transmits the antenna having the highest predicted reception level in the transmission slot. Antenna selection method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6127058A JPH07312590A (en) | 1994-05-16 | 1994-05-16 | Method for selecting antenna of diversity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6127058A JPH07312590A (en) | 1994-05-16 | 1994-05-16 | Method for selecting antenna of diversity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07312590A true JPH07312590A (en) | 1995-11-28 |
Family
ID=14950555
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6127058A Pending JPH07312590A (en) | 1994-05-16 | 1994-05-16 | Method for selecting antenna of diversity |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07312590A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999013660A1 (en) * | 1997-09-10 | 1999-03-18 | Matsushita Electric Industrial Co., Ltd. | Carrier sensor |
| WO2002049238A1 (en) * | 2000-12-15 | 2002-06-20 | Matsushita Electric Industrial Co., Ltd. | Portable radio device having antenna switching function |
| US7920441B2 (en) * | 2006-09-21 | 2011-04-05 | Atheros Communications, Inc. | Optimized time acquisition algorithm for low-power GPS-based watch applications |
| JP2012156880A (en) * | 2011-01-27 | 2012-08-16 | Hitachi Kokusai Electric Inc | Reception device |
| US8964510B1 (en) | 2005-09-22 | 2015-02-24 | Qualcomm Incorporated | Systems and methods for signal acquisition using predicted environmental context |
| US10855347B2 (en) | 2016-02-19 | 2020-12-01 | Kyocera Corporation | Base station and transmission antenna deciding method |
-
1994
- 1994-05-16 JP JP6127058A patent/JPH07312590A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999013660A1 (en) * | 1997-09-10 | 1999-03-18 | Matsushita Electric Industrial Co., Ltd. | Carrier sensor |
| WO2002049238A1 (en) * | 2000-12-15 | 2002-06-20 | Matsushita Electric Industrial Co., Ltd. | Portable radio device having antenna switching function |
| US8964510B1 (en) | 2005-09-22 | 2015-02-24 | Qualcomm Incorporated | Systems and methods for signal acquisition using predicted environmental context |
| US7920441B2 (en) * | 2006-09-21 | 2011-04-05 | Atheros Communications, Inc. | Optimized time acquisition algorithm for low-power GPS-based watch applications |
| JP2012156880A (en) * | 2011-01-27 | 2012-08-16 | Hitachi Kokusai Electric Inc | Reception device |
| US10855347B2 (en) | 2016-02-19 | 2020-12-01 | Kyocera Corporation | Base station and transmission antenna deciding method |
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