JP3110354B2 - Receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving device used for dual mode reception in a mobile communication system such as a car telephone.

[0002]

2. Description of the Related Art FIG. 7 shows an example of a conventional receiving apparatus. Referring to FIG. 1, reference numeral 1 denotes an antenna, 2 denotes a receiving amplifier for power-amplifying a high-frequency signal passing through the antenna 1, 3 denotes a distributor for distributing a high-frequency signal output of the receiving amplifier 2, and 7 denotes a distributor 3. A power detection unit which receives one of the high-frequency signals distributed by the above and outputs a switching signal, and 8 receives the other high-frequency signal from the distributor 3 and the switching signal from the power detection unit 7 and selects a conduction position. A receiving power control switch 9 for receiving a high-frequency signal from the receiving power control switch 8 and an on / off signal from the on / off controller 12 to perform power amplification, and 10 a receiving amplifier 9 and a receiving power control. A reception power control switch that receives a high-frequency signal from the switch 8 and selects a conduction position according to a switching signal from the power detection unit 7, and 11 is a reception power control switch. A receiver for receiving a radio frequency signal from 0.

Next, the operation will be described. First, in a state where the number of communication lines is large or a traffic state where the reception electric field is strong, the reception power level detected by the power detection unit 7 becomes larger than a specified value, and the reception power control is performed by a switching signal from the power detection unit 7. The switch 8 and the received power control switch 10 select the initially set receiving amplifier 9 side. Therefore, the high-frequency signal received by the antenna 1 is received by the receiving amplifier 2, the distributor 3, the receiving power control switch 8, and the receiving amplifier 9
And received power control switch 10 to be input to receiver 11.

On the other hand, in a traffic state in which the number of communication lines is small and the reception electric field is weak, the reception power level detected by the power detection unit 7 becomes smaller than a specified value, and the switching signal from the power detection unit 7 The reception power control switch 8 and the reception power control switch 10 are switched, and the high-frequency signal is input to the receiver 11 via the reception amplifier 2, the distributor 3, the reception power control switch 8 and the reception power control switch 10. At the same time, the on / off controller 12 shuts off the power supply of the reception amplifier 9 by the switching signal output from the power detection unit 7. As described above, due to the difference between the strong electric field when passing over the land area and the weak electric field when passing over the sea area, the power detection unit 7
The on / off controller 12 cuts off the power supply of the receiving amplifier 9 by the switching signal output from the, and reduces unnecessary power consumption of the receiving amplifier system. This technique is disclosed in, for example, JP-A-8-37482. It is disclosed in the gazette.

[0005] Further, the conventional TIA / EIA / IS-54
In the case where the -B analog / digital dual mode receiver is configured using one receiving amplifier, reception is performed in accordance with a digital mode receiver having high reception characteristics regardless of the traffic amount of the number of communication lines and the strength of the reception electric field. Amplifier electrical performance (noise figure NF and intermodulation distortion IM, etc.)
Therefore, in a traffic environment where only the analog mode receiver is used, the electrical performance is more than necessary, resulting in excessive power consumption.

[0006]

The conventional receiving apparatus is configured as described above, and determines whether to connect or bypass the receiving amplifier 9 by judging only the received electric field level value, and does not select it. Since the power supply of the receiving amplifier 9 is cut off, in the dual mode receiver as described above, when only the receiving level is detected and the receiving amplifier 9 is switched,
It is not possible to accurately judge whether the traffic (number of communication lines) is large or small, it is not possible to perform optimal low power consumption operation, and it is necessary to select whether to connect or bypass the receiving amplifier 9 and to select the receiving amplifier 9 that is not selected. Since the power supply is cut off, the circuit configuration becomes complicated, and there is a problem that the system is prevented from being reduced in size and inexpensive.

Further, the electrical characteristics of the receiving amplifier 9 are determined in accordance with the required digital mode having a high C / N (carrier-to-noise ratio), and the traffic state (the number of communication lines) cannot be detected. At the receiver, when the traffic situation is analog mode reception (when all the users are communicating with the analog mobile terminal), the difference between the required C / N of the digital mode and the required C / N of the analog mode is obtained. However, the noise figure NF, which is an electrical characteristic of the receiving amplifier, becomes excessive, and the intermodulation distortion IM, which is one of the standards of the receiving amplifier, becomes excessive in a traffic state where the receiving electric field level is low. There were challenges. Here, the current consumption of the receiving amplifier is
There is a correlation between the noise figure NF and the intermodulation distortion IM, and when the characteristics are determined for the digital mode, there is a problem that the current consumption of the system is wasted in other traffic conditions.

The present invention has been made to solve the above-mentioned problems, and provides a digital / analog reception mode, the number of communication lines, and a reception electric field value.
It is an object of the present invention to obtain a receiving apparatus capable of realizing low power consumption of a system by switching electrical characteristics of a receiving amplifier.

[0009]

In order to achieve the above object, a receiving apparatus according to the present invention comprises a receiving amplifier for amplifying a high-frequency signal received through an antenna to a level corresponding to a control voltage; A distributor for distributing a high-frequency signal power-amplified by the amplifier to each of the digital mode receiver and the analog mode receiver is provided, and a demodulator input from the digital mode receiver and the analog mode receiver is provided to the control device. group signals and electric field information
Then, the reception amplifier corresponding to the operation state of these digital mode receivers and analog mode receivers is used.
Control voltage to switch to sound index and intermodulation distortion
A predetermined control voltage is selected and input to the reception amplifier. The operation status here is the
Traffic condition, reception mode, reception electric field, etc.
And the number of receiving carriers.

The receiving device according to a second aspect of the present invention provides the receiving amplifier, comprising: a first transistor for amplifying a high-frequency signal received through the antenna; and an output signal of the first transistor from the control device. And a second transistor and a third transistor that linearly amplify according to the control voltage.

Further, a receiving apparatus according to a third aspect of the present invention is such that the receiving amplifier is controlled by a control voltage from the control apparatus so that power consumption is optimally suppressed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a receiving apparatus according to the present invention. In the drawing, 1 is an antenna, 2 is a receiving amplifier that receives a high-frequency signal and a control voltage via the antenna 1 and performs power amplification corresponding to the control voltage. And 3, a power-amplified high-frequency signal which is input to a digital mode receiver 4 and an analog mode receiver 5;
And a control device 6 for inputting demodulated signals and electric field information of the digital mode receiver 4 and the analog mode receiver 5, which are operating states of the digital mode receiver 4 and the analog mode receiver 5. function to output the control voltage corresponding to.

Next, the present invention will be described with reference to TIA / EIA / IS-
A case in which the present invention is applied to a digital / analog mobile communication system employing 54-B will be described. Here, the operation method of this mobile communication system uses an analog mode receiver as a control channel, an analog mode receiver or a digital mode receiver as a communication channel, and selects the control channel depending on the state of the mobile terminal. In other words, the system uses the digital mode as the communication channel when using the dual mode mobile terminal, and uses the analog mode as the communication channel when using the terminal dedicated to the analog mode. Considering the reception specification which is one of the wireless specifications of this system, the sensitivity specification of the digital mode receiver is BER = 3 × 10−2, reception input level−110 dB.
m, MLSE demodulation, sensitivity of analog mode receiver is 12 dBBSINAD, reception input level is -116 dBm,
FM demodulation is determined.

The required reception C / N in the digital mode receiver is 11 dB from Eb / N0, B (filter band), and T (transmission speed) (Trikes Publishing Co., Ltd., digital modulation / demodulation for mobile communication). Technology, P116, FIG. 13). On the other hand, the threshold level (Sanho Publishing Co., Ltd., easy-to-understand FM technology, P64) value of the analog mode receiver 12 dBSINAD is 9
dB. Here, a high-sensitivity receiver circuit using FM negative feedback results in a threshold level of weak power of about 1/5. Its value is 2 dB (Sanpo Publishing Co., Ltd., easy-to-understand FM technology, P143). Therefore, the noise figure NF required for the digital mode / analog mode receiver is 9 [dB] and 14 [dB], respectively. In such a system configuration, the noise figure NF at the antenna end is equal to the noise figure NF of the receiving amplifier.
It becomes dominant and is directly reflected in the reception sensitivity. on the other hand,
The input electric field level is UP / D between the mobile terminal and the radio base station.
Transmission power control is performed to keep OWN LINK constant. However, when the dynamic range (28 dB) of the transmission power control is exceeded, UP / DOWN
LINK breaks down, resulting in a high electric field or a weak electric field.

Therefore, as shown in FIGS. 2 and 3, the receiving amplifier 2 is, for example, a three-stage amplifying element (transistor).
A first transistor 13, a second transistor 14, which is configured by an amplifier and inputs a high-frequency signal from an antenna;
The third transistor 15 performs linear amplification, that is, class A amplification. In the receiving amplifier 2, the current consumption of the second and third transistors 14 and 15 is switched by the control voltage. By switching the current consumption,
The noise figure NF and the intermodulation distortion IM are switched, but the gain does not change. The relationship between the control voltage (current consumption) and the NF and IM ratios at this time is shown in FIGS.

Generally, the first transistor (first-stage amplifier) 13 is used for low-noise amplification, and the second transistor 14 and the third transistor (final-stage amplifier) 15 are used for high-output amplification. The current consumption of the second and third transistors 14 and 15 is controlled by the control voltage. In the mode, the noise figure NF and the intermodulation distortion IM are the best, and the current consumption is 610 mA. Next, in the mode, the noise figure NF and the intermodulation distortion IM are set to the required minimum values, so that the current consumption is as small as 360 mA. Lastly, the mode consumes only 410 mA because the mode reduces only the intermodulation distortion IM with respect to the mode.

Next, the flow of a high-frequency signal in the receiving apparatus shown in FIG. 1 will be described. The received wave is received through the antenna 1 and is distributed and input to the digital mode receiver 4 and the analog mode receiver 5 via the reception amplifier 2 and the distributor 3. The input modulated waves are demodulated corresponding to digital / analog, respectively, and the control device 6
And sends a received field strength (RSSI) signal to the receiver. The control device 6 sends a predetermined control voltage to the receiving amplifier 2 based on the reception field strength signal and the occurrence rate of the demodulated signal, and switches the electrical characteristics of the receiving amplifier. Next, traffic states with different reception electric field levels and different numbers of communication lines will be described. First, in the initial state (when the traffic is from 0 to 1 wave), the control channel transmits the control voltage Y as shown in FIG. Drive with
Next, the communication channel is switched to the digital mode reception. However, the control voltage Y is continuously transmitted from the control device 6 and the operation in the mode is continued. Secondly, as the traffic increases, the digital mode reception is performed as shown in FIG.
In the case where the number of waves is n or more and the combined power is m [dBμV] or more, the control device 6 transmits a control voltage X as shown in FIG. 4, and the receiving amplifier 2 switches to the mode operation.
This results in the electrical performance operation of the receiving amplifier 2 taking into account only the conventional digital mode.

Third, the received electric field level in the digital mode is reduced, and as shown in FIG.
In the case where the frequency is not less than the wave and not more than m [dBμV], the controller 6
Sends a control voltage Z as shown in FIG. 4, and the receiving amplifier 2 switches to the mode operation. Next, fourthly, the number of received waves in the digital mode is reduced, and as shown in FIG. 6, the traffic is in a state of a high electric field of only a few waves, and when the combined power is m [dBμV] or more, the control device 6 Sends out the control voltage Y. Thereby, the receiving amplifier 2
Switches to mode operation. Fifth, as shown in FIG. 6, when the traffic state is n waves or less and m [dBμV] or less so that the power of the digital reception wave also decreases,
The control device 6 sends out the control voltage Y, and the receiving amplifier 2 is kept in the mode operation. In this way, three kinds of control voltages are transmitted from the control device 6 to the receiving amplifier 2 by the two parameters of the number of waves (carriers) of digital mode reception and the combined power value, and the optimum receiving amplifier corresponding to the traffic situation 2 operation can be performed.

[0019]

As evident from the foregoing description, according to the present invention, conventionally, in accordance with the high digital mode of C / N, what was necessary to determine the electrical characteristics of the receiver amplifier, control
Digital mode receiver and analog mode
Based on demodulated signal and electric field information input from receiver
Digital mode receiver and analog mode
Operation status of the receiver (traffic status,
Reception mode, reception electric field and number of reception carriers)
Cut to the corresponding receiver amplifier noise figure and intermodulation distortion
The control voltage to be changed is selected from a plurality of predetermined control voltages and received.
Input to the receiver amplifier, and by switching the electrical characteristics (noise figure and intermodulation distortion) of the receiver amplifier,
The effect is obtained that a system operation with low power consumption of the receiving amplifier can be realized without deteriorating the reception quality. Further, unlike the related art, there is no reception power control switch for selecting whether to connect or bypass the reception amplifier and no on / off controller for shutting off the power supply of the reception amplifier not selected, so that the circuit configuration is simple. Thus, the effect that the system can be reduced in size and the price can be reduced can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a receiving device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a receiving amplifier in FIG.

FIG. 3 is an explanatory diagram showing a current value flowing through each transistor in each mode in FIG. 2;

FIG. 4 is an explanatory diagram showing electrical characteristics of the receiving amplifier in FIG.

FIG. 5 is a graph showing electrical characteristics of the receiving amplifier in FIG.

FIG. 6 is an explanatory diagram showing a relationship between traffic and combined power and an operation mode according to the present invention.

FIG. 7 is a block diagram showing a conventional receiving device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 antenna 2 reception amplifier 3 distributor 4 digital mode receiver 5 analog mode receiver 6 controller 13 first transistor 14 second transistor 15 third transistor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 1/16 H04B 7/26 H04Q 7/38

Claims (3)

(57) [Claims] 1. A receiving amplifier for power-amplifying a high-frequency signal received through an antenna to a level corresponding to a control voltage, and a digital-mode receiver and an analog-mode receiver for transmitting the high-frequency signal power-amplified by the receiving amplifier, respectively. And a reception amplifier corresponding to an operation state of the digital mode receiver and the analog mode receiver based on demodulated signals and electric field information input from the digital mode receiver and the analog mode receiver. Noise figure and
Control voltage for switching to intermodulation distortion
And a control device for selecting from pressures and inputting to the reception amplifier. A first transistor for amplifying a high-frequency signal received through the antenna; and a second transistor for linearly amplifying an output signal of the first transistor in accordance with a control voltage from the control device. The receiving device according to claim 1, comprising a third transistor and a third transistor. 3. The receiving device according to claim 1, wherein the receiving amplifier is controlled by a control voltage from the control device so as to suppress power consumption without deteriorating reception quality. .