JPH11163977A - Mobile phone - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable a telephone call with little auditory noise on a mobile phone. SOLUTION: In the PHS telephone 10, for the purpose of downsizing, noise wrapping around from a pattern of a wiring board and noise generated when a transmission radio wave from an antenna 19 wraps around to a receiving side are easily reproduced from a receiver 16. The microphone 11 picks up not only the transmission signal but also the surrounding noise,
Easy to send to the other side of the call. The transmission level detector detects the level of the transmission signal, and when the level is below the reference level, the transmission gain of the transmission attenuator 12 is reduced.
When the reception level detected by the reception level detection unit 15 is lower than the reference level, the reception attenuator unit 14 is controlled to reduce the level at which noise is output from the receiver 16. When there is a transmission signal or a reception signal, the gain is increased, and the influence of noise is reduced by using the ear masking effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a PHS (Personal
The present invention relates to a mobile phone such as a Handyphone System.

[0002]

2. Description of the Related Art In recent years, portable telephones of the PHS system and the like have been widely used. Various systems coexist in the mobile phone system, and the PHS system is one of them. The miniaturization of various types of mobile phones is rapidly progressing, and with the development of high-density mounting technology and the miniaturization of various components used, the degree of freedom in arranging components on a printed wiring board and designing wiring patterns is decreasing. I have. In addition, the arrangement of parts is restricted from the viewpoint of usability as a mobile phone.

FIG. 5 shows a schematic external configuration of a typical PHS telephone 1. The housing 2 of the PHS telephone 1 is formed to have a size and a shape that are easy to hold and operate with one hand. A microphone 3 for receiving a call is arranged in a part of the housing 2. A liquid crystal display (hereinafter abbreviated as “LCD”) 4 for movably displaying various information, an operation key 5 for performing operations such as calling a communication partner, and the like are provided near the center of the front side of the housing 2. Be placed. A receiver 6 for reproducing audio information from a communication partner is also provided in the housing 2. An antenna 7 for performing wireless communication with a base station is provided at an end of the housing 2. The PHS telephone 1 performs data communication with the base station at regular intervals even when no telephone call is made, confirms that the PHS telephone 1 is within the service range of the base station, and checks the antenna of the base station. The transmission output is adjusted according to the distance from the vehicle. In the PHS communication method, TDMA (Time Division
The frequency of the radio wave limited by the time-division multiplexing method called Multiple Access), for example, the 1.9 GHz band is effectively used, and the TDD (Time Division Duplex) method is used.
The same frequency band is used for transmission and reception, and transmission and reception are switched by time division. For this reason, it is necessary to compress the audio signal temporally during transmission, and to expand the audio signal during reception. The radio wave transmitted from the antenna 7 is time-divided and becomes an intermittent burst.

In the PHS telephone 1, a transmission radio wave is generated intermittently in a burst form. As shown in FIG.
The S telephone 1 is compactly configured, and the distance between the antenna 7 and the electronic circuit inside the housing 2 is short. For this reason, the transmitted radio wave flows into the voice processing circuit on the receiving side, and noise is easily generated. In order to prevent such noise, a ground pattern on a printed wiring board is separated, or a reactance element whose self-resonance frequency matches the frequency of a radio wave is attached to an input portion of a circuit or the like.

[0005]

SUMMARY OF THE INVENTION As shown in FIG.
In the S telephone 1, it is difficult to achieve both miniaturization and quantification, and prevention of noise due to inflow of transmission radio waves. Separation of a ground pattern makes it difficult to design a printed wiring board, and requires installation of a reactance element. Causes cost increase. In addition, as the size of the housing 2 is reduced, the position of the microphone 3 and the position of the mouth of the caller are separated from each other. Therefore, the gain of the microphone amplifier is increased. It is disadvantageous for noise. That is, if the gain of the microphone amplifier is increased, the noise is amplified and sent to the other party of the call even when the caller is not talking. Amplifying noise and sending it to the other party degrades call quality,
In addition, the fact that ambient noise is heard by the other party makes the feeling of use of the PHS telephone 1 worse.

An object of the present invention is to provide a portable telephone capable of making a call with little noise.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a portable telephone capable of controlling a transmission gain and a reception gain detects a transmission level and determines whether or not the transmission level is equal to or higher than a transmission reference level. A level detection means, a reception level detection means for detecting a reception level and determining whether or not the reception level is equal to or higher than a reception reference level, and transmitting a speech signal in response to a judgment result of the transmission level detection means and the reception level detection means. Control means for lowering the transmission gain when the level is determined to be lower than the transmission reference level, and lowering the reception gain when the reception level is determined to be lower than the reception reference level. A mobile phone characterized by the following.

According to the present invention, the transmission gain and the reception gain of the portable telephone can be controlled. The transmission level is detected by the transmission level detecting means, and it is determined whether or not the transmission level is equal to or higher than the transmission reference level. The reception level is detected by the reception level detection means, and it is determined whether or not the reception level is equal to or higher than the reception reference level. The control means, in response to the determination results of the transmission level detection means and the reception level detection means, reduces the transmission gain when it is determined that the transmission level is lower than the transmission reference level. When it is determined that the receiving level is lower than the receiving reference level, the receiving gain is reduced. By appropriately setting each level, when the transmission level does not reach the transmission reference level, the transmission gain can be reduced to prevent noise or the like from being transmitted to the communication partner.
Also, when the reception level is detected and the reception level is lower than the reception reference level without receiving a call from the other party, the reception gain can be lowered to reduce the noise receiver reproduced from the receiver or the like.

Further, the present invention provides a portable telephone capable of controlling a transmission gain, a transmission level detecting means for detecting a transmission level and determining whether or not the transmission level is equal to or higher than a transmission reference level. Control means for controlling the transmission gain to be reduced when the transmission level is determined to be lower than the transmission reference level in response to the determination result of the detection means. .

According to the present invention, the transmission level is detected by the transmission level detection means, and when it is determined that the transmission level is less than the transmission reference level, the control means controls the transmission gain so as to reduce the transmission gain. Therefore, it is possible to prevent only ambient noise from being sent to the talker when the talker is talking.

Further, according to the present invention, in a portable telephone capable of controlling a receiving gain, a receiving level detecting means for detecting a receiving level and determining whether or not the receiving level is equal to or higher than a reference level, and a result of determination by the receiving level detecting means. And control means for controlling to reduce the receiving gain when it is determined that the receiving level is lower than the receiving reference level in response to the request.

According to the present invention, when it is determined that the reception level detected by the reception level detection means is lower than the reference reception level, the control means controls the reception gain so as to be low. It is possible to reduce the output of an acoustic signal reproduced from a receiver or the like when not talking, thereby suppressing noise reproduction.
When the transmission level is equal to or higher than the transmission reference level, the transmission gain can be increased and the output of the audio signal can be increased. If the sound output increases, even if the noise is amplified, the noise is masked by the sound, and the noise is less noticeable in terms of hearing.

In the present invention, the reference level can be changed. According to the present invention, since the reference level for comparing the level detected by the reception level detection means or the transmission level detection means can be changed, it is possible to take into account the loudness of the caller and the surrounding noise level, etc. Can be adjusted to different levels.

In the present invention, the detection time required for the level detection for the determination can be changed.

According to the present invention, the detection time can be changed when comparing the level detected by the transmission level detection means or the reception level detection means with the reference level. , And appropriate gain switching can be performed. For example, when the detection time is lengthened, the gain does not change even if the detection level instantaneously exceeds the reference level due to pulse noise, and the gain can be changed after the telephone call is actually performed. If the detection time is shortened, the delay time from the start of the call to the switching of the gain can be reduced.

Further, in the present invention, the portable telephone is characterized by performing a telephone call in a PHS system. According to the invention, P
A mobile phone that transmits radio waves in bursts and intermittently using the HS method. The level at which the transmitted radio waves wrap around to the receiving side and reproduces the noise generated is reduced, thereby improving the signal-band noise ratio in the sense of hearing. Can be achieved.

[0017]

FIG. 1 shows a schematic electrical configuration of a PHS telephone 10 according to an embodiment of the present invention. The content of the transmission by the voice of the caller is input to the microphone 11. The output of the microphone 11 is input to a transmission attenuator 10 and a transmission level detector 13 for adjusting the transmission gain. The reception signal from the other party is input to the reception attenuator 14 and the reception level detector 15, respectively. The output of the receiving attenuator unit 14 is provided to the receiver 16 and is converted from an electric signal to an acoustic signal, so that the receiving signal reaches the ear of the caller. The voice signal output from the voice attenuator 12 and the voice signal input to the voice attenuator 14 and the voice level detector 15 are processed by the voice processor 17. The audio processing unit 17 converts the voice of the transmission signal from analog to digital and performs time compression processing, and also time-expands the received signal to perform digital / analog conversion and reproduces the voice. In the radio unit 18, PH
S communicates with the base station, transmits a transmission signal obtained by modulating a carrier wave with a transmission signal to the communication partner via the base station, and receives a reception signal from the communication partner via the base station. The received signal is demodulated and separated from the carrier wave and supplied to the audio processing unit 17. Transmission and reception of wireless power between the wireless unit 18 and the base station are performed via the antenna 19. The control unit 20 performs data communication with a base station and performs overall control of the PHS telephone 10 in order to establish connection of a communication line.

In the PHS telephone 10 shown in FIG. 1, a gain detection adjustment unit 30 including a transmission attenuator unit 12, a transmission level detection unit 13, a reception attenuator unit 14, and a reception level detection unit 15, for example, as shown in FIG. Conventional PH
This is a different part from the S telephone 1. The transmission level detection unit 13 includes a detection level change unit 31 and a detection time change unit 32. The reception level detection unit 15 includes a detection level change unit 51 and a detection time change unit 52.

FIG. 2 shows a control procedure performed by the control unit 20 shown in FIG. Control is started from step a0 and step a
1 is a state in which the transmission gain and the reception gain are each low,
That is, the attenuation in the transmission attenuator unit 12 and the reception attenuator unit 14 is set to be larger than usual. In step a2, it is determined whether or not a call is in progress. If it is determined that the user is not talking, step a1
Return to When it is determined that the user is talking, in step a3, it is first determined whether or not there is a transmission signal having a predetermined transmission reference level or higher. The transmission signal input to the microphone 11 is input to the transmission level detection unit 13 and notifies the control unit 20 that the level of the transmission signal is higher than the threshold which is the transmission reference level. Is done. Step a3
Then, the control unit 20 controls the transmission attenuator unit 12 to have a normal gain based on the determination result of the transmission level detection unit 13 to reduce the signal attenuation. By the operation of increasing the transmission gain in step a4, the transmission signal generated by the microphone 11 passes through the transmission attenuator unit 12 with the normal gain, passes through the voice processing unit 17 and the radio unit 18, and , From the antenna 19 to the base station.

Next, when the transmission signal does not reach the predetermined level, the transmission signal generated by the microphone 11 is input to the transmission level detection unit 13 and the transmission level is transmitted to the control unit 20 when the transmission level exceeds the threshold. Is also notified that the level is low. The control unit 20 moves from step a3 to step a5 based on the result of this determination, and controls the transmission attenuator unit 12 to lower the transmission gain. By this operation, the transmission signal generated by the microphone 11 passes through the transmission attenuator unit 12 with a gain lower than usual, passes through the voice processing unit 17 and the radio unit 18, and is transmitted from the antenna 19 to the base station. Thus, noise in the transmitted transmission radio wave can be reduced.

After the processing in step a4 or step a5, it is determined in step a6 whether or not the reception level is equal to or higher than a threshold which is a reception reference level. When there is a reception signal of a certain level or higher, the signal received by the antenna 19 is input to the reception attenuator unit 14 and the reception level detection unit 15 via the radio unit 18 and the audio processing unit 17. The reception level detection unit 15 notifies the control unit 20 that the reception level is higher than the threshold. Control unit 20
Controls the receiving attenuator unit 14 to have a normal gain in step a7 based on the result of this determination, and sets the receiving gain to a high state. With this operation, the receiving signal is sound-reproduced at a normal gain from the receiver 6 and can be heard.

In the case of a reception signal less than a certain level, a signal received by the antenna 19 is input to the reception attenuator unit 14 and the reception level detection unit 15 via the radio unit 18 and the voice processing unit 17. Receiving level detector 1
5 notifies the control unit 20 that the reception level is low. Based on the result of this determination, the control unit 20 controls in step a8 such that the attenuation of the receiving attenuator unit is made larger than usual and lower than the normal receiving gain as a whole. By this operation, the reception signal reproduced from the receiver 6 has a low level as a whole, and the level of noise included for various reasons is suppressed, so that the reception signal is almost inaudible. Upon completion of the process in the step a7 or the step a8, the process returns to the step a2.

FIG. 3 shows the relationship between a detection signal from the transmission level detector 13 or the reception level detector 15 and a reference level. As shown in FIG. 3A, it is assumed that no audio signal is input from time t0 to time t1, and an audio signal is input after time t1. If the threshold level Lref is set near the lower limit of the input level of the sound after the time t1, the gain becomes low when there is no sound from the time t0 to the time t1, and the gain is shown in FIG. Thus, the output level reproduced is further reduced. Since the detection level exceeds the threshold after time t1, the gain increases and the reproduced output level increases. At this time, although the noise increases at the same time, since the output level of the audio signal is higher, the noise is not noticeable due to the ear masking effect, and the signal band noise ratio seems to be improved. Note that, as shown in FIG.
Even if there is noise such as a peak value exceeding a threshold due to pulse noise during the period when there is no audio signal up to, the detection time W is appropriately set and the input averaged within the detection time W is set. If the level is compared with the threshold value, it is possible to prevent the gain from changing at the peak of the instantaneous noise. Such a change of the detection time W is performed by the detection time changing units 32 and 52 in FIG.

The threshold and the detection time W as shown in FIG. 3 are changed by the detection level change units 31 and 51 and the detection time change units 32 and 52.
Can be automatically performed by the control unit 20. For example, a threshold is set at a level slightly lower than the lower limit level when there is a voice input, and even if the pulse noise when there is no voice input, the detection time W that does not exceed the threshold if averaged over time is determined in the past. It can be set automatically while learning based on the results.

FIG. 4 shows a PHS according to another embodiment of the present invention.
2 shows a schematic electrical configuration of the telephone 60. This embodiment is similar to the embodiment of FIG. 1, and corresponding portions are denoted by the same reference numerals, and redundant description will be omitted. In the present embodiment, the input unit 61 is provided, and the threshold of the detection level changing units 31 and 51 is manually changed from the input unit 61, and the detection time W of the detection time changing units 32 and 52 is manually changed. Is possible. The input unit 61 can also be used as the operation keys 5 as shown in FIG. 5, for example.

In the embodiment shown in FIG. 1 or FIG. 4, the gain of the transmission system is adjusted by the transmission attenuator 12 and the transmission level detector 13, and the gain of the reception system is adjusted by the reception attenuator 14 and the reception level detector 15. Although both detection adjustments are provided, it is possible to provide only one of them. In the case of only one of them, the number of components is reduced, and the cost can be reduced.

[0027]

As described above, according to the present invention, the transmission gain and the reception gain are automatically controlled based on the results determined by the transmission level detection means and the reception level detection means, and the transmission level and the reception level are controlled. When the reception level is lower than the transmission reference level and the reception reference level, the transmission gain and the reception gain are reduced, respectively, so that the radio inflow noise which is conspicuous at a low volume, the noise wrapping around from the wiring pattern, or the vicinity of the talker. Noise can be limited. When the volume is high, the transmission gain and the reception gain are each increased by the perceptual masking effect of the caller's ear to make the noise level relatively inconspicuous even if the noise reproduction level increases. Can be.

Further, according to the present invention, when the transmission level is below the transmission reference level, the transmission gain is reduced, so that only the surrounding noise is transmitted to the communication partner when the caller is not talking. Thus, it is possible to prevent a situation where only noise is reproduced from the receiver on the other side. If the caller speaks,
Since the transmission level becomes equal to or higher than the transmission reference level and the transmission gain increases, it is possible to clearly reproduce the content spoken by the caller from the receiver on the communication partner side. At this time, noise is reproduced at the same time. However, if the voice level is high, the noise is masked in terms of hearing, and even if noise is transmitted at the same time, the noise level in hearing can be lowered.

Further, according to the present invention, when the reception level is lower than the reception reference level, the reception gain can be reduced, and the acoustic output of radio inflow noise and noise wrapping around from the wiring pattern can be reduced. When the receiving level is higher than the receiving reference level, the receiving gain is increased, so that the noise level is also high.However, since the level of the audio signal is high, the noise is not much bothersome due to the masking effect of the ear. The audible noise level can be reduced.

According to the present invention, since the reference level for comparing the level detected by the transmission level detection means or the reception level detection means can be changed, the signal-to-noise ratio in the sense of hearing can be improved. The level can be set.

Further, according to the present invention, since the detection signal at the time of level detection can be changed, the detection time can be adjusted according to the nature of the noise, and the audible signal-to-noise ratio can be improved.

Further, according to the present invention, it is possible to improve the audible signal-to-noise ratio during a PHS communication.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic electrical configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of FIG.

FIG. 3 is a graph showing a state in which gain adjustment of the embodiment of FIG. 1 is performed.

FIG. 4 is a block diagram showing a schematic electrical configuration of another embodiment of the present invention.

FIG. 5 is a simplified front view showing the appearance of a conventional PHS telephone 1.

[Explanation of symbols]

 Reference Signs List 10, 60 PHS telephone 11 Microphone 12 Transmission attenuator 13 Transmission level detector 14 Reception attenuator 15 Reception level detector 16 Receiver 17 Audio processing unit 18 Radio unit 19 Antenna 20 Control unit 30 Gain detection adjustment unit 31, 51 Detection Level change unit 32, 52 Detection time change unit 61 Input unit

Claims (6)

[Claims] 1. A portable telephone capable of controlling a transmission gain and a reception gain, comprising: a transmission level detecting means for detecting a transmission level and determining whether or not the transmission level is equal to or higher than a transmission reference level; Receiving level detecting means for detecting and determining whether or not the level is equal to or higher than the receiving reference level; and responding to the determination results of the transmitting level detecting means and the receiving level detecting means, when the transmitting level is less than the transmitting reference level. Control means for reducing the transmission gain when it is determined that there is, and reducing the reception gain when it is determined that the reception level is lower than the reception reference level. 2. A portable telephone capable of controlling a transmission gain, comprising: a transmission level detecting means for detecting a transmission level and determining whether or not the transmission level is equal to or higher than a transmission reference level; Control means for controlling the transmission gain to be lowered when it is determined that the transmission level is lower than the transmission reference level in response to the determination result. 3. A portable telephone capable of controlling a reception gain, wherein the reception level is detected, and a reception level detection means for determining whether or not the reception level is equal to or higher than a reception reference level, and a response to the determination result of the reception level detection means. And control means for reducing the receiving gain when it is determined that the receiving level is lower than the receiving reference level. 4. The mobile phone according to claim 1, wherein the reference level is changeable. 5. The detection time required for level detection for the determination is changeable.
5. The mobile phone according to any one of 4. 6. The mobile phone according to claim 1, wherein the mobile phone performs a telephone call in a PHS method.