JP3225164B2 - Mobile communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention transmits communication state information during mobile communication without increasing the amount of transmission data.
The present invention relates to a portable mobile communication device.

[Background of the Invention] In recent years, with the rapid development of communication technology due to advances in semiconductor manufacturing technology and digital signal processing technology, many small mobile communication devices such as mobile phones and cordless phones have been provided to the market. I have.

[0003] These mobile communication devices are characterized by significantly higher communication quality and privacy than conventional analog communication systems, and are also suitable for non-telephone communication such as data transmission and facsimile. From the analog communication system to the digital communication system.

[0004]

2. Description of the Related Art Conventionally, in mobile communication in a mobile communication device, a communication path (between a mobile station and a base station,
Or between mobile stations), which constantly changes,
Even if a digital communication system that is resistant to noise is adopted, it must always be considered that the received wave changes in a time series due to the propagation characteristics of the radio wave, and the received data changes accordingly.

That is, in mobile communication, for example,
Due to the decrease in electric field strength due to fading, interference waves of signals from other stations, or when the distance from the communication partner station is long, errors cannot be avoided in the received data, and errors occur. Data cannot be used.
In such a case, the error correcting code (error correcting cod
By using e), even if some error occurs in the received data, the error is corrected on the receiving side.

If the communication quality deteriorates beyond the correction capability of the error correction code, for example, a CRC (Cycl
ic Redundancy Check), the received data error is detected by a cyclic code, and if the probability exceeds a certain value and it is determined that many received data are erroneous, the received data is discarded and erroneous received data is fetched. It is designed to prevent that.

[0007]

However, in such a conventional mobile communication device, once the received electric field intensity becomes lower than a certain reference value or when a strong interference wave is generated, the received electric field intensity becomes lower. An error will also occur in the control signal to avoid inconveniences such as a decrease in strength and interference waves,
As a result, an error is detected in the control signal itself by the above-described received data error detection, and the control signal information is also discarded. Therefore, the control signal for avoiding inconvenience does not sufficiently fulfill its role, and communication is not performed. You will be disconnected.

Therefore, in order to continue communication, a communication link must be re-established by a control channel.
During this time, communication (call) has to be interrupted, which causes inconvenience in use.

To solve this problem, for example, a status bit indicating a communication state is provided in transmission data for one bit,
When the communication state is deteriorated due to a decrease in electric field strength or an interference wave, by setting this status bit to “H”,
It is also conceivable to take an appropriate measure corresponding to the communication state on the receiving side, but at present, the information area is set without waste of one bit in the physical slot constituting the transmission data. Providing a new information area causes a new problem of deterioration of data efficiency.

[0010] The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a communication state in mobile communication without adding data to transmission data and consuming an information area. An object of the present invention is to provide a portable mobile communication device capable of transmitting information.

[0011]

Means for Solving the Problems The first aspect of the present invention is shown in FIG.
As shown in (1), in a portable mobile communication device 1 that transmits information in frame units and establishes a frame period based on synchronization information provided for each frame, the current communication state is a state in which information transmission is effective for information transmission. State determining means 2 for determining whether or not the communication state is not valid. When the state determining means 2 determines that the communication state is not valid for information transmission, the unique word as synchronization information for establishing a frame period is inverted. Inverting output means 3 for outputting a clock signal,
The received data is fetched and arrayed based on the timing , the array data is output non-inverted in one of the reference clock signal states "H" and "L", and the array data is output in the other state. A shift register for inverting and outputting, a memory for storing bit information used as a uniquad, and the reference
Generate a clock signal that is twice as long as the clock signal
Means a sequence de outputted from the bit information stored in the memory and the shift register - data and the time clock signal
Compared based on the timing of No., the comparison circuit outputs a coincidence pulse when they match, the reference clock
Capture the signal according to the signal and the output signal of the comparison circuit,
When the reference clock signal is in one of the "H" and "L" states and a coincidence pulse is input from the comparison circuit, a non-inverted uni-quad detection signal is output, and the reference clock signal is output. Means for outputting an inverted uni-quad detection signal when the signal is in the other state of "H" or "L" and a coincidence pulse is input from the comparison circuit. Features.

The state judging means 2 has an error detecting section 2a for performing an error detection using, for example, a cyclic code, and an error rate of received data obtained as a result of the error detection by the error detecting section 2a is set to a predetermined reference value. If the value exceeds the value, it is determined that the communication state is not a state effective for information transmission. Alternatively, the state determination means 2 includes a reception electric field strength measurement section 2b for measuring the electric field strength of the reception wave, and an interference electric field strength measurement section 2c for measuring the electric field strength of the interference wave. If the electric field intensity measured by 2b is equal to or less than a predetermined value, or if the electric field intensity measured by the interference electric field intensity measuring unit 2c is equal to or more than a predetermined value, it is determined that the communication state is not valid for information transmission. .

The detecting means detects 1/1 of the reference clock signal.
Based on the double clock signal of two cycles, the inverted signal and the non-inverted signal of the specific information in the received data are compared with reference specific information serving as a comparison reference value, and the specific information in the received data is inverted at a coincident timing. Since it is detected whether or not the communication is performed, inversion / non-inversion of the specific information in the received data is reliably detected in addition to the above-described invention of claim 1, 2, 3 or 4, and the communication state is deteriorated. Can take immediate measures.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. 2 to 5, FIG.
The same reference numerals are given to the same parts.

First, the configuration of this embodiment will be described.

FIG. 2 is a block diagram showing the overall configuration of the mobile communication device 1 of the present embodiment. 2, the mobile communication device 1 according to the present embodiment includes an antenna 11, a high-frequency unit 12,
It comprises an SP (Digital Signal Proceser) 13, an audio encoder / decoder 14, a D / A converter 15, a speaker 16, an A / D converter 17, a microphone 18, and a control unit 19.

The antenna 11 is an omnidirectional antenna for transmitting and receiving voice data to and from a predetermined base station (or mobile station).

As shown in FIG. 2, the high frequency section 12 includes an antenna switch 21, a receiving section 22, a local oscillator 23, and a transmitting section 23, and performs frequency conversion processing.

When receiving a radio wave from a base station (or a mobile station) based on a control signal from the control unit 19, the antenna switch 21 is switched to the receiving unit 22 side.
When transmitting a radio wave to the base station (or mobile station), the radio wave can be switched to the transmitting unit 24 side.

The receiving section 22 includes a low noise amplifier 22a,
When a received signal is input from the antenna 11 via the antenna switch 21, the received signal is amplified by the low-noise amplifier 22a, and then the received signal is amplified from 1.9 GHz by the down converter 22b. Around 250MHz (1stIF),
Next, around 10 MHz (2nd IF), then 1 MHz
Frequency conversion (down-conversion) is performed on the IF signal in the vicinity (3rd IF), and the received signal is further converted into an A / D converter 2
The signal is converted into a digital signal by 2c and output to the DSP 13.

The local oscillator 23 has a PLL (Phase Locked L).
oop) The receiving unit 22 and the transmitting unit 24 by the synthesizer
And outputs a local oscillation signal for performing frequency conversion.

The transmitting section 24 is composed of a D / A converter 24a, an up-converter 24b, and a power amplifier 24c. The D / A converter 24a converts the π / 4 shift QPSK modulated wave input from the DSP 13 into an analog signal. After the conversion, the frequency is converted (up-converted) from 10 MHz to around 250 MHz and then to the 1.9 GHz band by the up-converter 24b, and the power is amplified by the power amplifier 24c.
Radiate from the antenna 11 through the antenna. DSP
Reference numeral 13 denotes a processor dedicated to digital signal processing having the functions of a modem unit 25 and a channel coder 26.
The SP 13 also has an error detection function by CRC.

The modem unit 25 performs π / 4 shift QPSK modulation and demodulation processing. Specifically, at the time of reception, the modem unit 25 converts the IF signal input from the reception unit 22 into an IQ signal.
The data is demodulated, and the demodulated signal is converted into a serial data string and transferred to the channel coder 26. On the other hand, at the time of transmission, IQ data is created from the data transferred from the channel coder 26 to generate π / 4 A modulated wave of shift QPSK is generated, and a modulated wave of π / 4 shift QPSK is output to the transmission unit 24.

The channel coder 26 includes a unique word generation circuit 31 and a unique word detection circuit 32.
It performs frame synchronization and data transmission / reception processing by DMA (Time Division Multiple Access). Specifically, at the time of reception, a unique word (synchronization signal) is received from reception data transmitted from the modem unit 25. The extracted data is synchronized with the frame, and the control data and the audio data in the received data are unscrambled, and the processing such as scrambling is released. The control data is transferred to the control unit 19, and the audio data is sent to the audio code / decoder 14 On the other hand, at the time of transmission, control data and the like are added to the audio data transferred from the audio codec / decoder 14 to generate transmission data, and after processing such as scrambling is performed, a unique word or the like is added. The format is added to the data, inserted into the TDMA frame at a predetermined timing, and output to the modem unit 25.

The speech codec / decoder 14 comprises a speech codec and a PCM (Pulse Code Modulation) codec, and performs compression / expansion processing of digital speech data by the speech codec. Analog / digital conversion is performed by the PCM codec. Processing is performed. Specifically, at the time of reception, the ADPCM audio signal (4 bit) transmitted from the channel coder 26
× 8 kHz = 32 kbps) to PCM audio signal (8 bi
(t × 8 kHz = 64 kbps), which is expanded by decoding, and the expanded PCM audio signal is D / A-converted by the D / A converter 15 to be converted into an analog low-frequency signal, and the analog audio signal obtained by the conversion is converted. Is output to a speaker 16 via an amplifier (not shown), and at the time of transmission, an analog audio signal input from a microphone 18 is A / D converted by an A / D converter 17 and a digital signal obtained by the conversion is obtained. P which is an audio signal
The CM audio signal is encoded into an ADPCM audio signal, compressed and output to the channel coder 26.

The speaker 16 outputs sound to the outside based on the sound signal output from the receiving unit of the mobile communication device 1, and the microphone 18 inputs the sound signal to the transmitting unit of the mobile communication device 1. It is for doing.

The control unit 19 includes a CPU 27, a ROM 28,
The CPU 27 is configured by a RAM 29, outputs various control signals to each unit in the mobile communication device 1 based on a predetermined program stored in the ROM 28, and controls the entire device. , A semiconductor memory for storing programs and data used in the mobile communication device 1, and a RAM 29 for storing program data and the like used during execution of program processing by the CPU 27 and a semiconductor used as a work area. Memory.

FIG. 3 is a block diagram showing an example of the unique word generating circuit 31 in the channel coder 26 shown in FIG.

As shown in FIG. 3, the unique word generating circuit 31 of this embodiment comprises a unique data memory 41, a shift register group with presets 42, an inverter 43, and a multiplexer 44. A circuit composed of a memory 41 for use and a shift register group with preset 42 has an inverter 43,
A multiplexer 44 is added.

The unique word generated by the unique data memory 41 and the preset shift register group 42 is input to the first input terminal IN1 of the multiplexer 44 via the inverter 43 and directly to the second input terminal IN2. When the inverted select signal input to the input terminal CONTROL of the multiplexer 44 is “H”, the signal input to the first input terminal IN1 is output from the output terminal OUT, while the inverted select signal is “H”. In the case of L ", since the signal input to the second input terminal IN2 is output from the output terminal OUT, the unique word can be easily inverted (or not inverted) and output based on the inverted select signal.

FIG. 4 is a block diagram showing an example of the unique word detection circuit 32 in the channel coder 26 shown in FIG.

As shown in FIG. 4, the unique word detection circuit 32 of this embodiment includes a unique word memory 51, a digital comparison circuit 52, a shift register 53, an inverter 54, a clock doubler 55, a delay circuit 56, a one-shot 57.

The unique word memory 51 stores bit information used as a unique word. The digital comparison circuit 52 stores the bit information stored in the unique word memory 51 and the shift register 53.
Are compared with each other, and if they are all coincident, "H" is output as a coincidence pulse from the output terminal OUT to the clock input terminal CK of the one-shot 57 and the CPU 27. If the bits do not match, "L" is output. The shift register 53 holds the unique word information input from the data input terminal IN, and stores the unique word information at the clock input terminal CK.
And outputs the unique word information to the digital comparison circuit 52 based on the reference clock signal input from the select input terminal SEL.

That is, the unique word in the received data is inputted from the data input terminal IN of the shift register 53, and when the reference clock signal is "H", the non-inverted signal (Q ₁ ... Q _n)
There is output, whereas, in the case of the reference clock signal is "L", the inverted signal from the shift register 53 to the comparator circuit ^{_{52 (Q 1 * ... Q n}} *, Note, A ^* is a top bar symbols representing reversal of A Shall be output).

The reference clock signal is supplied to the inverter 5
4 and input to the input terminal D of the one-shot 57 and also to the clock doubler 55.

In the clock doubler 55, a double clock signal having a half cycle of the reference clock signal is generated, and is input to the strobe terminal STROBE of the comparison circuit 52 after a predetermined time delay by the delay circuit 56.

Next, the operation of the above embodiment will be described with reference to FIGS. FIG. 5 is a waveform diagram for explaining an operation example of the unique word detection circuit 32.

At the time of reception, first, the CRC
Is determined, and if the error detection rate is equal to or less than the set value, it is determined that the current communication state is good. At the time of transmission, the unique word generation circuit 31 shown in FIG. “L” is output. In this case, the unique word output from the multiplexer 44 is transmitted as a non-inverted unique word.

In this case, the unique word taken into the shift register 53 at the time of reception is as shown in FIG.
As shown in (1), a non-inverted unique word array is fetched as array data in the shift register 53, and the digital comparison circuit 52 changes the switch selection state of the shift register 53 during selection of inverted outputs (Q1 *... Qn *). "H" is output as a coincidence pulse from the digital comparison circuit 52. At this time, the input terminal D of the one-shot 57 is output.
Since "L" is input as the inverted clock signal, the inverted signal output from the one-shot 57 becomes "L" in this state, and it is detected that the received unique word is in the non-inverted state. You.

On the other hand, if the error detection rate in CRC exceeds a preset value at the time of reception, it is determined that the communication quality has deteriorated. At the time of transmission, the unique word generation circuit 31 shown in FIG. “H” as select signal
Is output, and the unique word output from the multiplexer 44 is transmitted as an inverted unique word via the inverter 43.

In this case, the unique word taken into the shift register 53 at the time of reception is as shown in FIG.
As shown in FIG. 8, the inverted unique word array is fetched as array data in the shift register 53, and the switch selection state of the shift register 53 is selected by the digital comparison circuit 52 between non-inverted outputs (Q ₁ ... Q _n ). During this time, "H" is output as a coincidence pulse from the digital comparison circuit 52. At this time, "H" is input to the input terminal D of the one-shot 57 as an inverted clock signal. The inverted signal output from the shot 57 becomes "H", and it is detected that the received unique word is in an inverted state.

As described above, when it is detected that the received unique word is in the inverted state, as a countermeasure, for example, when the partner station is a base station, the transmission power is increased or the channel is shifted to a channel with less interference. Preparations are made, and if the partner station is a mobile station, handover / roaming and preparation for transition to a channel with less interference are performed.

In the case of an asynchronous system such as a cordless telephone, since the master stations are not synchronized with each other, channel signals in slots before and after which did not interfere at the start of communication may be affected by an oscillation accuracy error. Over time, the interference may be stronger than the beginning or end of the slot. In such a case, the interference usually does not occur in the entire data but starts at the beginning or end of the data. Therefore, information on the occurrence of interference
If it is known early by the method of this embodiment, even if an error is detected in the received data, only the control data can be used as valid data and used for avoiding interference.

As described above, in this embodiment, the unique word detection circuit 32 determines whether the current communication state is valid for information transmission, and determines whether the current communication state is valid for information transmission. When it is determined that there is no unique word, the unique word in the frame is inverted by the unique word generation circuit 31 and output, so that the inverted information can be used as 1-bit communication state information.

Therefore, the communication state information during mobile communication can be transmitted to the communication partner without consuming the information area. If there are many transmission errors, the communication status can be transmitted to the communication partner, and the countermeasure is taken early. As a result, transmission quality can be improved.

Although the invention made by the inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof. Needless to say,

For example, in the above-described embodiment, the case where a unique word is used as the specific information indicating the communication state is described as an example, but the specific information is not limited to the unique word.

In the above embodiment, the current communication state is determined based on the error rate when the CRC cyclic code is used. However, the current communication state may be determined based on the reception electric field strength and the interference electric field strength. May be used to determine the communication state. However, in an actual communication state, the method described in this embodiment is more effective in a communication situation in which the reception electric field strength is low or the communication error rate is suppressed even when the interference electric field strength is high. Deemed practical.

[0049]

According to the first aspect of the present invention, the state determining means determines whether the current communication state is valid for information transmission and determines that the communication state is not valid for information transmission. In this case, by inverting and outputting the uniquad in the frame by the inverting output means, the inversion information can be used as 1-bit communication state information, thereby moving without consuming the information area. Communication state information at the time of communication can be transmitted to the communication partner. By using a unique word, communication state information can be obtained when synchronous information is detected, and a countermeasure against deterioration of the communication state can be taken at an early stage.
Further, based on a double clock signal having a half cycle of the reference clock signal, the inverted signal and the non-inverted signal of the specific information in the received data are compared with reference specific information serving as a comparison reference value, and received at a coincidence timing. Uni in data
By detecting whether the quad is inverted,
The inversion and non-inversion of the specific information in the received data can be reliably detected, and a countermeasure can be taken at an early stage for the deterioration of the communication state.

According to the second aspect of the present invention, it is determined whether the communication state is valid for information transmission based on the result of the error detection performed by the error detection unit using the cyclic code. In addition to the above-described invention, it is possible to accurately determine whether the current communication state is a state effective for information transmission.

In this case, according to the third aspect of the present invention, based on the electric field intensity measured by the reception electric field intensity measurement unit or the electric field intensity measured by the interference electric field intensity measurement unit, the communication state is set to a state effective for information transmission. By determining whether the current communication state is valid, it is possible to accurately determine whether the current communication state is a state effective for information transmission.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main configuration of the present invention.

FIG. 2 is a block diagram illustrating an overall configuration of a mobile communication device according to the present embodiment.

FIG. 3 is a block diagram showing an example of a unique word generation circuit in the channel coder shown in FIG.

FIG. 4 is a block diagram showing an example of a unique word detection circuit in the channel coder shown in FIG.

FIG. 5 is a waveform chart for explaining an operation example of the unique word detection circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mobile communication apparatus 2 State determination means 3 Inversion output means 4 Detecting means 31 Uni-quad detection circuit 32 Uni-quad generation circuit 51 Uni-quad memory 52 Digital comparison circuit 53 Shift register

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q 7/00-7/38 H04L 1/00-1/22

Claims (3)

(57) [Claims] 1. A portable mobile communication device for transmitting information on a frame basis and establishing a frame period based on synchronization information provided for each frame, wherein a current communication state is a state effective for information transmission. State determining means for determining whether or not there is, and when the state determining means determines that the communication state is not valid for information transmission, inverts and outputs a unique word as synchronization information for establishing a frame period. Receiving data based on the timing of the reference clock signal and arranging the received data, and outputting the array data in a non-inverted state in one of the "H" and "L" states of the reference clock signal. SEQ de in the other state - a shift register for inverting and outputting the data, uni - mulberry - a memory for storing bit information used as a de 1/2 period of the reference clock signal A double clock signal
Means for generating, SEQ de outputted from the bit information stored in the memory and the shift register - Thailand and data the multiplying clock signal
A comparison circuit that compares based on the timing and outputs a coincidence pulse when the two coincide with each other; and a signal corresponding to the reference clock signal and an output of the comparison circuit.
When the reference clock signal is in one of the "H" and "L" states and a coincidence pulse is input from the comparison circuit, a non-inverted uniquad detection signal is output. Means for outputting an inverted uniquad detection signal when the reference clock signal is in the other state of "H" or "L" and a coincidence pulse is input from the comparison circuit; A portable mobile communication device comprising: 2. The apparatus according to claim 1, wherein said state determination means has an error detection unit for performing error detection using a cyclic code, and an error rate of reception data obtained as a result of the error detection by the error detection unit is set to a predetermined reference value. 2. The portable mobile communication device according to claim 1, wherein if it exceeds, it is determined that the communication state is not valid for information transmission. 3. The receiving device according to claim 2, wherein the state determining unit includes: a receiving electric field intensity measuring unit that measures the electric field intensity of the receiving wave; and an interference electric field intensity measuring unit that measures the electric field intensity of the interference wave. If the electric field intensity measured by the unit is equal to or less than a predetermined value, or if the electric field intensity measured by the interference electric field intensity measuring unit is equal to or more than a predetermined value, it is determined that the communication state is not valid for information transmission. The portable mobile communication device according to claim 1, wherein: