JP2002300052A - Wireless communication terminal adopting digital system, wireless control circuit, wireless communication method and wireless communication program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless communication terminal adopting a digital system that enables reduction of the number of components and low power consumption and is mounted with a squelch function and to provide a wireless control circuit, a wireless communication method and a wireless communication program. SOLUTION: The wireless communication terminal is provided with a reception section 100 of a single superheterodyne structure, an analog/digital converter section 113 that quantizes IQ signals outputted from the reception system 100 into 16-bit data, a root Nyquist filter 115, a logic circuit section 119, a DSP(digital signal processor) 121, and a CPU 123. The logic circuit section 119 includes a bit extract section 153 that extracts 6 bits from the 16-bit data, a square sum calculation section 155 that calculates a square sum in 6 bits, a threshold value discrimination section 157 that compares the square sum in 6-bits with a threshold value, a register that latches the square sum in 6 bits, a discrimination result and a mask bit of a threshold value discrimination value 157 and ORs the discrimination result with the mask bit and a timer section 159 that intermittently operates the reception system 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a radio communication terminal device,
The present invention relates to a wireless control circuit, a wireless communication method, and a program for executing the method, and in particular, a digital wireless communication terminal device having a function of determining the presence or absence of a received electric field,
The present invention relates to a wireless control circuit, a wireless communication method, and a wireless communication program.

[0002]

2. Description of the Related Art In a radio communication system such as a cellular phone or a PHS, a base station is always present in communication between terminals.
Communication between the base station and the terminal is synchronized by the base station. On the other hand, in a wireless communication system used for fire-fighting radio or disaster prevention radio, which allows direct communication between terminals, when the terminals directly communicate with each other, the communication does not pass through a base station, so that the terminal A signal arrives. In order for a terminal used in this wireless communication system to operate as a wireless communication device, it is necessary to efficiently detect signals that arrive irregularly.

FIG. 4 shows a conventional wireless communication system (the latter).
1 shows an example of a terminal used in. As shown in the figure, the terminal includes an antenna 11, an RF unit 13, a first intermediate frequency conversion unit (1stIF) 15, and a second intermediate frequency conversion unit (2ndI
F) section 17, quadrature modulator (IQ DEM) 19, oscillators (OSC) 21a, 21b, and automatic gain control section (AG)
C) A receiving system 10 having a double superheterodyne structure constituted by 22, an A / D converter (ADC) 23, a logic circuit (GA) 25, a DSP 27, and a CPU 29. The terminal further includes a squelch circuit (SQ) 3
1 and RSSI (Received S
(ignal Strength Indicator) detection circuit 33 is provided inside the receiving system. Note that the terminal usually has a transmission system, a power supply system, a speaker, a microphone, and the like in addition to these, but these are omitted in FIG.

[0004]

In the above-mentioned conventional wireless communication system, an FM detection system is generally employed. When the detection method is used, it is necessary to sufficiently suppress an interference wave by an analog filter.
Has a double superheterodyne structure. However, the receiving system of the double superheterodyne structure has a problem that it is difficult to reduce the size and weight of the terminal and to reduce the power consumption because the number of components is inevitably increased, and a narrow band because the characteristics in the receiving band are disturbed. There was a problem that it was difficult to realize this.

[0005] In addition, the terminal used in the above-mentioned conventional wireless communication system includes a squelch circuit (SQ) 3 as described above.
1 is provided. Normally, in an analog wireless communication device, the amplitude level in a voice band greatly fluctuates depending on the presence / absence of voice. Therefore, the presence / absence of reception of a carrier (voice signal) is determined with reference to a demodulated signal in this voice band. It is difficult. In addition, there is no characteristic difference between the noise level in the audio band when there is no input and the noise level in the audio band included in the voice. Therefore, the squelch circuit 31 outputs the signal of the second intermediate frequency amplified by the limiter amplifier (L-AMP) 35 to the FM detector (DET) 3.
The presence / absence of carrier wave reception is determined in accordance with the level outside the audio band of the signal obtained by the detection at 7, that is, the increase or decrease of the noise level outside the audio band.

However, with the digitization of communication for the purpose of improving frequency use efficiency, improving communication quality, and securing communication confidentiality, the detuning interval of a carrier (voice signal), that is, the frequency bandwidth of the carrier, has been increased. Since the noise level outside the audio band decreases when the width is reduced, there is a problem that the conventional squelch circuit 31 cannot be used in actual operation.

For example, as shown in FIG. 5, the noise level outside the voice band changes according to the electric field input level, and the noise level decreases as the electric field input level increases. Utilizing this characteristic, when the bandwidth of the carrier is, for example, 12.5 kHz, the squelch circuit 31 uses the squelch function when the noise level outside the band falls below the sensitivity point with reference to a preset sensitivity point level. Work. On the other hand, when the bandwidth is reduced to half of 6.25 kHz, the noise level outside the band is reduced as a whole and always falls below the sensitivity point regardless of the electric field input level. As described above, when the frequency bandwidth of the carrier is narrowed, there is a problem that the original squelch function of the squelch circuit 31 does not work.

[0008] In a radio communication system such as a portable telephone or a PHS, a multiplexing method is used to divide the same frequency into a plurality of time slots.
le Access: time division multiple access). In the wireless communication system using the TDMA method,
The base station instructs the terminal on which slot to use for communication, and the terminal communicates with the base station in synchronization with the slot timing specified by the base station.

However, even if the TDMA method is adopted in the above-mentioned conventional wireless communication system in which the terminals can directly communicate with each other, when the terminals perform the direct communication, each terminal performs the direct communication using which slot. No slot control is performed. Therefore, the terminal responds to the signal transmitted to itself, and every time it receives a signal of a predetermined frequency regardless of the slot, the terminal determines whether or not the received signal is transmitted to itself. It is necessary to judge with. Therefore, the CPU 29 with relatively large power consumption
Has a problem that it is difficult to reduce the power consumption of the terminal because the terminal operates on a signal not related to itself. In addition, as described above, since signals are transmitted irregularly from terminals that perform direct communication, there is also a problem that a deviation occurs from a predetermined slot timing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is a digital wireless communication terminal device having a squelch function and capable of realizing a reduction in the number of components and a reduction in power consumption. It is an object to provide a control circuit, a wireless communication method, and a wireless communication program.

[0011]

According to a first aspect of the present invention, there is provided a digital radio communication terminal apparatus which quadrature demodulates a quadrature-modulated received signal to obtain an I signal and a Q signal. , An A / D converter that A / D converts the I signal and the Q signal to quantize each signal into a predetermined number of bits, and a signal that is quantized by the A / D converter. A bit extraction unit for extracting a part of bit information from the digital I signal and the digital Q signal of a predetermined number of bits, a square sum calculation unit for calculating a sum of squares of each bit information extracted by the bit extraction unit, Comparing the sum of squares obtained by the sum of squares calculation means with a threshold value to determine a magnitude relationship between the sum of squares and the threshold value; Judgment It is obtained by a communication processing / control unit that performs communication processing or control according to the result.

According to a second aspect of the present invention, in the wireless communication terminal device according to the first aspect, the threshold value is a desired amplitude for the wireless communication terminal device to determine a reception electric field. Level.

According to a third aspect of the present invention, in the wireless communication terminal device according to the first or second aspect, the communication processing / control unit determines that the threshold value determining unit determines that If the sum of squares is equal to or larger than the threshold value, the operation is started, and if the sum of squares is smaller than the threshold value, the state of low power consumption is maintained.

According to a fourth aspect of the present invention, in the wireless communication terminal device according to the first, second or third aspect, the multiplexing method of the wireless communication terminal device is TDMA.
(Time-division multiple access), a storage unit for storing mask information set in advance for each slot in order to select a slot to be used for communication, and a determination result obtained by the threshold determination unit is: The information is sent to the communication processing / control means based on the mask information stored in the storage means.

According to a fifth aspect of the present invention, in the wireless communication terminal device according to the fourth aspect, the determination result by the threshold value determination means is binary information of 0 or 1; When the information is binary information of 0 or 1, a logical sum operation means for calculating a logical sum of the judgment result and the mask information for each slot is provided.

According to a sixth aspect of the present invention, in the wireless communication terminal device according to the fifth aspect, the judgment result obtained by the threshold value judging means is that the sum of squares is not less than the threshold value. If the sum of squares is smaller than the threshold value, the value is "0". In the mask information, "0" means a mask and "1" means an unmask. .

According to a seventh aspect of the present invention, in the wireless communication terminal according to the fourth, fifth or sixth aspect, the determination result sent to the communication processing / control means is a predetermined number of slots. Successively, when the result is obtained when the sum of squares is smaller than the threshold,
The mask information stored in the storage means is automatically released.

According to an eighth aspect of the present invention, there is provided a wireless communication terminal according to the first, second, third, fourth, fifth, sixth or seventh aspect, wherein the multiplexing method of the wireless communication terminal is used. In the case of TDMA (Time Division Multiple Access), a timer is provided for operating the receiving means for a predetermined time at a predetermined timing for each slot.

A wireless communication terminal according to a ninth aspect is the wireless communication terminal according to the first, second, third, fourth, fifth, sixth, seventh or eighth aspect. The reception electric field strength of each slot is measured based on the sum of squares calculated by the sum of squares calculation means.

According to a tenth aspect of the present invention, there is provided a wireless communication terminal according to the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth aspect. When starting transmission, the communication processing / control means selects an optimal slot based on the sum of squares calculated by the sum of squares calculation means.

The wireless communication terminal according to claim 11 is the wireless communication terminal according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; It has a single superheterodyne structure.

A digital wireless communication method according to a twelfth aspect of the present invention provides a digital wireless communication method, comprising: a quadrature demodulation of a quadrature-modulated received signal to output an I signal and a Q signal;
An A / D conversion step of A / D converting the signal and the Q signal to quantize each signal into a predetermined number of bits;
A bit extraction step of extracting a part of bit information from each of the digital I signal and the digital Q signal having a predetermined number of bits quantized in the A / D conversion step, and a step of extracting each bit information extracted in the bit extraction step. A sum of squares calculating step of calculating a sum of squares, and a threshold determining step of comparing the sum of squares obtained in the calculating of the sum of squares with a threshold value to determine a magnitude relationship between the sum of squares and the threshold value And a communication processing / control step of performing communication processing or control according to the determination result obtained in the threshold value determination step.

The wireless communication method according to claim 13 is
13. The wireless communication method according to claim 12, wherein the threshold is a desired amplitude level for determining a reception electric field.

A wireless communication method according to claim 14 is
The wireless communication method according to claim 12 or 13,
The communication processing / control step activates communication processing / control means for performing communication processing or control if the sum of squares is equal to or greater than the threshold value as a result of the determination in the threshold value determination step, Is smaller than the threshold value, the communication processing / control means is kept in a state of low power consumption.

The wireless communication method according to claim 15 is
15. The wireless communication method according to claim 12, 13 or 14, wherein when the multiplexing method of the wireless communication method is TDMA (Time Division Multiple Access), mask information for selecting a slot to be used for communication is set in advance in a slot. Each threshold is set, and the determination result obtained in the threshold determination step is:
It is sent to the communication processing / control means based on the mask information.

The wireless communication method according to claim 16 is
16. The wireless communication method according to claim 15, wherein when the determination result in the threshold determination step is binary information of 0 or 1, and the mask information is also binary information of 0 or 1, And a logical sum operation step of calculating a logical sum of the determination result and the mask information.

The wireless communication method according to claim 17 is
17. The wireless communication method according to claim 16, wherein a determination result obtained in said threshold value determination step is "1" if said sum of squares is equal to or greater than said threshold value, and said sum of squares is equal to said threshold value. When the mask information is smaller than “0”, “0” means mask and “1” means unmask.

The wireless communication method according to claim 18 is
The wireless communication method according to claim 15, 16 or 17, wherein the determination result sent to the communication processing / control means is:
The mask information is automatically released when a result obtained when the sum of squares is smaller than the threshold value is obtained continuously for a predetermined number of slots.

A wireless communication method according to claim 19 is
Claims 12, 13, 14, 15, 16, 17 or 18
In the wireless communication method described in (1), when the multiplexing method of the wireless communication method is TDMA (Time Division Multiple Access), the receiving step is performed at a predetermined timing for each slot for a predetermined time.

Further, the wireless communication method according to claim 20 is a wireless communication method according to claims 12, 13, 14, 15, 16, 17, 18
20. The wireless communication method according to 19, further comprising a receiving electric field intensity step of measuring a receiving electric field intensity of each slot based on the square sum obtained in the square sum calculating step.

A wireless communication program according to claim 21 is a wireless communication program according to claims 12, 13, 14, 15, 16, 17, 1,
It is for causing a computer to execute the wireless communication method described in 8, 19 or 20.

The radio control circuit according to claim 22 is:
Bit extraction means for extracting a part of bit information from each of the I signal and the Q signal quantized to a predetermined number of bits;
A sum of squares calculating means for calculating a sum of squares of each bit information extracted by the bit extracting means, and a sum of squares obtained by the sum of squares calculating means is compared with a threshold value to determine the sum of squares and the threshold. Threshold value determining means for determining a magnitude relationship between values.

Further, the radio control circuit according to claim 23 is the radio control circuit according to claim 22, wherein when the multiplexing method is TDMA (time division multiple access), a slot used for communication is selected in advance. There is provided storage means for storing mask information set for each slot, and the determination result obtained by the threshold value determination means is sent based on the mask information stored in the storage means.

In the digital wireless communication terminal device according to claim 1 of the present invention, the wireless control circuit according to claim 22, the wireless communication method according to claim 12, and the wireless communication program according to claim 21, the receiving means ( In the receiving step), the quadrature-modulated received signal is subjected to quadrature demodulation to output an I signal and a Q signal, and A / D conversion means (A / D conversion step) A / D converts the I signal and the Q signal. Thereby, each signal is quantized to a predetermined number of bits, and in a bit extraction unit (bit extraction step), a part of each of the digital I signal and the digital Q signal of the predetermined number of bits quantized by the A / D conversion unit is used. The bit information is extracted, and the sum of squares of each bit information extracted by the bit extraction means is calculated in a sum of squares calculation means (sum of squares calculation step). In the threshold value determining means (threshold value determining step), the square sum obtained by the square sum calculating means is compared with the threshold value to determine the magnitude relationship between the square sum and the threshold value, and the communication processing / control means ( Communication processing / control step)
In the above, communication processing or control is performed according to the determination result obtained by the threshold value determination means.

In particular, a wireless communication terminal device according to claim 2
In the wireless communication method according to the thirteenth aspect and the wireless communication program according to the twenty-first aspect, it is desirable that the threshold value is a desired amplitude level for determining a reception electric field.

Therefore, the presence or absence of communication can be determined based on the magnitude relationship between the sum of squares and the threshold value, and the threshold value can be set to a desired level. Even if the level is lowered, the presence or absence of the received electric field can be determined to realize the squelch function.

A wireless communication terminal device according to claim 3,
In the wireless communication method according to claim 14 and the wireless communication program according to claim 21, the communication processing / control means (communication processing / control step) determines that the sum of squares is equal to or greater than the threshold value as a result of the determination by the threshold value determination means. If the sum is less than the threshold, the power consumption is kept low.

Therefore, when the square value is smaller than the threshold value, that is, when there is no communication, the amount of power consumed by the communication processing / control means is suppressed, and when the square value is equal to or more than the threshold value, that is, when communication is performed. Since the communication processing / control means is operated only when the power is on, the power consumption of the apparatus can be reduced.

Also, a wireless communication terminal device according to claim 4,
In the wireless control circuit according to claim 23, the wireless communication method according to claim 15, and the wireless communication program according to claim 21, when the multiplexing method is TDMA (Time Division Multiple Access), a slot used for communication is selected. The mask information for performing the determination is set in advance in the storage means for each slot, and the determination result obtained by the threshold value determination means is sent to the communication processing / control means based on the mask information.

In particular, the wireless communication terminal device according to claim 5,
In the wireless communication method according to claim 16 and the wireless communication program according to claim 21, the determination result by the threshold value determination unit is binary information of 0 or 1, and the mask information is binary information of 0 or 1. At this time, the logical sum operation means (logical sum operation step) calculates the logical sum of the determination result and the mask information for each slot.

In particular, in the wireless communication terminal device according to the sixth aspect, the wireless communication method according to the seventeenth aspect, and the wireless communication program according to the twenty-first aspect, the determination result obtained by the threshold value determining means is a sum of squares. "1" if the threshold is exceeded
When the sum of the squares is smaller than the threshold value, the mask information is “0”. In the mask information, “0” means a mask and “1”
Means unmask.

As described above, by masking an undesired slot using the mask information (setting the mask information to "0"), it is possible to prevent the communication processing / control means from being activated by communication irrelevant to the terminal itself. Therefore, low power consumption of the device can be realized. Also, by using 0 or 1 binary signals, these can be direct external control signals.

A wireless communication terminal according to claim 7,
In the wireless communication method according to claim 18 and the wireless communication program according to claim 21, when the determination result sent to the communication processing / control means is continuous for a predetermined number of slots and the sum of squares is smaller than the threshold value, , The mask information is automatically released. Therefore, the masked state does not continue forever, and after a predetermined time has elapsed from the end of the communication, it is possible to return to the normal standby state without operating the communication processing / control means.

A wireless communication terminal according to claim 8,
In the wireless communication method according to the nineteenth aspect and the wireless communication program according to the twenty-first aspect, when the multiplexing method is TDMA (Time Division Multiple Access), the timer means sets a predetermined timing for each slot for a predetermined period of time. By operating the receiving means, the receiving step is executed only for a predetermined time. Therefore, the receiving means does not always operate in the standby state, but operates only for a predetermined time for each slot to sample the received signal.
Therefore, the power consumed by the receiving means can be reduced by the predetermined time, so that low power consumption can be realized. Further, it is possible to suppress a malfunction caused by performing sampling overlapping a plurality of slots.

A wireless communication terminal according to claim 9,
In the wireless communication method according to the twentieth aspect and the wireless communication program according to the twenty-first aspect, the reception electric field strength of each slot is measured based on the sum of squares calculated by the square sum calculation means (square sum calculation step). . Therefore, by using the sum of squares, not only a squelch function but also a received field strength display (RSSI) function can be realized.

In the wireless communication terminal device according to the tenth aspect, when starting transmission, the communication processing / control means selects an optimal slot based on the sum of squares calculated by the sum of squares calculation means. . As described above, since the communication processing / control means only needs to refer to the sum of squares to detect the radio wave state for each slot, it is possible to determine the slot to be used in a short time without a time lag. As a result, it is possible to reduce the disconnection of the talk head and the call delay.

Further, in the radio communication terminal device according to the eleventh aspect, the receiving means has a single superheterodyne structure. Conventionally, the receiving system had to have a double superheterodyne structure, but the single superheterodyne structure can also achieve the above-described effects. Therefore, the number of components for the receiving system can be reduced, and the mounting area can be reduced. As a result, the size of the device can be reduced.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the embodiments, the wireless communication terminal device and the wireless communication method according to the present invention will be described in detail, but the wireless communication program according to the present invention is a program for executing the wireless communication method. Therefore, the description is included in the following description of the wireless communication method.

The wireless communication terminal device of the present embodiment is used in a digital wireless communication system such as a fire-fighting radio or a disaster-prevention radio in which terminals can directly communicate with each other. In the digital wireless communication system, the ratio between the noise level and the signal level in the demodulated signal when defining the sensitivity point is determined by the modulation method. Therefore, the wireless communication terminal device according to the present embodiment has the demodulated signal level and the noise level. A squelch function is realized by performing digital processing using the difference between the squelch function and the squelch function. Note that the multiplexing method is a TDMA (Time Division Mu) that divides the same frequency into a plurality of temporal slots.
ltiple Access).

FIG. 1 is a block diagram showing a wireless communication terminal according to an embodiment of the present invention. However, in the figure, a transmission system, a power supply system, a speaker, a microphone, and the like are omitted. In FIG. 1, the wireless communication terminal device according to the present embodiment includes:
Antenna 101, RF section 103, intermediate frequency conversion section (IF) 105, automatic gain control section (AGC) 107, quadrature demodulator (IQ DEM) 109, and oscillator (OS
C) Receiving system (RX) having a single superheterodyne structure corresponding to the receiving means according to the claim having 111
100 and an A / D conversion unit (A
DC) 113 and a root Nyquist filter (RNF)
115 and a logic circuit unit (GA) corresponding to the wireless control circuit
119 and a DSP 121 corresponding to the communication processing / control means.
And a CPU 123.

First, in the receiving system (RX) 100, a signal received by the antenna 101 is filtered by the RF unit 103, and is converted into an intermediate frequency by the intermediate frequency conversion unit (IF) 105. Next, the level is adjusted by an automatic gain control unit (AGC) 107, and quadrature demodulation is performed by a quadrature demodulator (IQ DEM) 109 to output I and Q signals. The I signal and the Q signal output from the quadrature demodulator 109 of the receiving system 100 are A / D converted by an A / D converter (ADC) 113 to be quantized to 16 bits, respectively, and then a root Nyquist filter ( RNF) 115 removes the influence of intersymbol interference, and the logic circuit (GA) 1
19 is input.

FIG. 2 shows a block diagram of a wireless communication terminal device centering on the logic circuit section 119. In the figure, a logic circuit unit 119 includes a distribution unit 151 and a bit extraction unit 153 corresponding to bit extraction means in the claims.
A sum of squares calculation unit 155 corresponding to the sum of squares calculation means;
This is a gate array including a register 117 corresponding to a storage unit, a threshold value determination unit 157 corresponding to a threshold value determination unit, and a timer unit 159 corresponding to a timer unit. First, the distribution unit 151 includes the logic circuit unit 11.
The 16-bit digital signal input to 9 is distributed in two directions. One is sent to the DSP 121, and the other is sent to the bit extraction unit 153 of the logic circuit unit 119. In addition,
The signal sent to the DSP 121 is a digital signal converted into a format that the DSP 121 can process.

Further, the bit extracting section 153
This is to extract continuous 6-bit data from the 16-bit data sent from 1. However, from which bit the upper 6-bit data is extracted is determined by the sensitivity point level of the squelch which is set in advance, but the level at which the sensitivity point is set differs depending on the modulation method. For example, in the QPSK modulation method, when trying to obtain a bit error rate (BER) of about 1%, a C / N (carrier to noise) ratio of about 8 dB is required. It is set to a level 8 dB higher than that.

In the case of BPSK, a C / N ratio of 4 dB is required, in the case of 8PSK, a C / N ratio of 8 dB is required, and in the case of 16QAM, a C / N ratio of 16 dB is required. These ratios are not affected by band changes.

As described above, in the wireless communication system employing the QPSK modulation method, the A / D
When the analog IQ signal is quantized into 16 bits by the conversion unit 113 and the analysis capability of, for example, 6 dB is obtained with one bit, at least two bits of data are required to realize the squelch function. As an example, when the 16-bit data has the bit-to-amplitude relationship shown in FIG. 3 and the sensitivity point is set to 1.0 mVpp, the bit extraction unit 153
Extracts the fifth to tenth 6 bits. However, as described above, since two bits are sufficient to realize the squelch function, the lower two bits, that is, the fifth and sixth data may be used to realize the squelch function. At this time, since the number of bits is small, the amount of processing required for calculating the sum of squares can be reduced, and the processing time required for calculating the sum of squares can be reduced.

The sum-of-squares calculating section 155 obtains the amplitude data of the demodulated signal by calculating the sum of the squares of the I signal and the Q signal. In order to realize the squelch function in the present embodiment, an RSSI (Received Signal Strength)
th indicator (reception field strength display) function, the sum of squares calculation unit 155 calculates the sum of squares of the 6 bits extracted by the bit extraction unit 153, and sends the calculation result to the threshold value determination unit 157. . In the present embodiment, the TDMA system is used as a multiplexing system, and one frame is composed of a plurality of slots, for example, four slots. Therefore, the 6-bit square sum calculated by the square sum calculation unit 155 is calculated for each slot. Are stored in the register 117.

The register 117 has the same number of areas as the number of slots constituting one frame, and has four areas corresponding to each slot when one frame is composed of four slots. Each area has a square sum calculation unit 1
55, the result (0 or 1) determined by the threshold value determination unit 157, and the mask corresponding to the mask information set forth in the claims set by the CPU 123. Bit (0 or 1)
Are stored.

On the other hand, as described above, the square sum calculation unit 15
The 6-bit sum of squares (amplitude data) obtained in step 5 is sent to threshold determination section 157. Threshold determination unit 157
Is the amplitude data sent from the sum of squares calculation unit 155 and the DSP having a fixed ratio of the amplitude level to the device noise level.
When the amplitude data is equal to or greater than the threshold value, the value of the register 117 is set to “1”.
And “0” if the amplitude data is smaller than the threshold value.
Enter That is, a flag of 0 or 1 is set in an area for storing the determination result by the threshold value determination unit 157 in the register 117. The threshold value set by the DSP 121 is basically equal to the above-described sensitivity point, but can be set to a desired level according to the system.
Therefore, when a system with high stability that does not malfunction is constructed, a threshold value higher than the sensitivity point may be set.

In the area of the register 117 for storing the mask bit, a mask bit of 0 or 1 which can be directly set by a control signal from the CPU 123 is stored. A mask bit is set for each slot, "0" means a mask, and "1" means an unmask. In other words, this slot is ignored for the slot whose mask bit is “0”, regardless of the amplitude data and the determination result.
Register 1 for the slot whose mask bit is "1"
17 is sent to the CPU 123. For example, in the example shown in FIG. 2, the mask bit of slot 1 is “1” and the mask bits of the remaining slots 2 to 4 are “0”, so that the determination result of slot 1 is “1”.
Is sent to the CPU 123. This function is performed by the logical sum operation unit 118 shown in FIG. 2, which corresponds to the logical sum operation means in the claims that calculates the logical sum (OR) of the mask bit and the determination result for each slot.

In this embodiment, a counter is provided in the logic circuit section 119 so that the communication can be automatically resumed when a call is lost. If "0" continues for the slot of
The logic circuit unit 119 determines that the call has been completed, and automatically releases the mask. Note that releasing the mask means returning to a state where no mask bit is set. The logic circuit unit 119 can automatically release the mask without activating the CPU 123.

The timer section 159 is for operating the receiving system 100 only for a very short time in each slot. More specifically, a power supply (not shown) for supplying power to the receiving system 100 is used alone. ON / OFF operation is controlled.
For example, a receiving system 1 for 1 ms for a slot of 10 ms
By operating 00, sampling processing of a received signal is performed for each slot. The reason why the sampling time can be set short in this way is that, particularly in digital communication, a symbol point of a specified level is passed within a fixed time. For example, in the case of a π / 4 DQPSK (π / 4 shift QPSK) modulation method, an IQ signal Since the power intensity is substantially constant without passing through the zero point, the sampling time can be set shorter than in 16QAM or QPSK modulation.

By setting the sampling time short, the amount of power consumed by the receiving system 100 is reduced. As in the above example, when one slot is 10 ms and the sampling time is 1 ms, the power consumption in the receiving system 100 is reduced. Power 1
/ 10. In addition, if the sampling time is short, the possibility of sampling over two slots can be reduced. The sampling time is preset by the CPU 123.

As described above, the receiving system 100 includes the timer unit 1
It is activated or disconnected by an instruction from the DSP 59, but can also be controlled by an instruction from the DSP 121. When the receiving system 100 is not operating, a DC circuit unit (not shown) of the quadrature demodulator (IQ DEM) 109
Takes a relatively long time to stabilize, so the timer unit 1
It is possible to further improve the performance by always operating regardless of the instruction from 59.

The DSP 121 has a logic circuit section 119.
Demodulation of the I signal and the Q signal obtained through the distribution section 151 of the logic circuit section 119 and the threshold value determination section 157 of the logic circuit section 119.
The threshold value is set for. Note that the DSP 121 that the wireless communication terminal device is waiting to receive is in a sleep state. Further, the CPU 123 refers to the determination result of the unmasked (mask bit is “1”) slot from the logical sum of the determination result of the threshold value determination unit 157 stored in the register 117 and the mask bit. , DSP
It controls the activation of the 121. The mask bit is set by the CPU 123 for each slot. In addition, CPU
123 is also in a sleep state during reception standby.

Next, as a wireless communication method according to the present invention,
The operation of the wireless communication terminal device according to the present embodiment will be briefly described. First, the receiving system 100 checks each slot (10
The received signal is sampled only for a very short time (1 msec) during (msec). While the receiving system 100 is operating, the signal received by the antenna 101 is filtered by the RF unit 103. Next, the level is adjusted by an automatic gain control unit (AGC) 107 and quadrature demodulated by a quadrature demodulator (IQ DEM) 109. Next, the I signal and the Q signal output from the quadrature demodulator 109 are converted to an A / D converter (ADC) 113.
Are quantized to 16 bits each. Next, the 16-bit digital signal is converted to a root Nyquist filter (RN).
F) At 115, the effect of intersymbol interference is removed.

Next, the digital signal is distributed by the distribution unit 151 of the logic circuit unit 119, and one of the digital signals is sent to the bit extraction unit 153. After the 6-bit data is extracted from the 16-bit data by the bit extraction unit 153, the 6-bit square sum is calculated by the square-sum calculation unit 155. The sum of squares calculation unit 155 stores the 6-bit sum of squares in the register 117 and sends the sum to the threshold value determination unit 157. Next, the threshold sum determination unit 157 compares the 6-bit sum of squares with the threshold value. If the sum of squares is equal to or greater than the threshold value, "1" is input to the register 117, and the sum of squares exceeds the threshold value. If smaller, "0" is input.

Next, a value obtained by the logical sum of the determination result input from the threshold value determination unit 157 and the mask bit stored in the register 117 is sent to the CPU 123. If this value is “1”, the CPU 123 starts to start communication in an unmasked slot. At this time, the CPU 123 sends the DSP 12
1 and the DSP 121 demodulates the I signal and the Q signal input through the distribution unit 151.

As described above, in the wireless communication terminal apparatus and the wireless communication method according to the present embodiment used in the digital wireless communication system, the sum of squares of the 6 bits extracted by the bit extraction section 153 and the threshold value are determined. Since the presence / absence of communication is determined by comparing, even if the noise level is reduced as a result of narrowing the frequency bandwidth of the carrier wave, the presence / absence of the reception electric field can be determined to realize the squelch function.

Undesired slots can be masked by taking the logical sum of the determination result and the mask bit, so that the DSP 121 or CPU 12 which consumes relatively large power due to communication irrespective of its own terminal.
3 can be prevented. Therefore, low power consumption can be realized.

Further, a slot counter is provided in the logic circuit section 119, and if the determination result “0” obtained by the logical sum in the state where the mask bit is set is counted continuously for a predetermined number of times, the logic The circuit section 119 can return to a state where no mask bit is set. Therefore, the masked state does not last forever,
After a lapse of a predetermined time after the end of the communication, the wireless communication terminal device can be returned to the normal standby state.

Further, the wireless communication terminal apparatus and the wireless communication method according to the present embodiment provide the receiving system 10 in the standby state.
“0” does not always operate because of sampling.
Sampling processing is performed for each slot only during the minute time set by 59, and power is not supplied to the receiving system 100 at other times. Therefore, the power consumed by the receiving system 100 can be suppressed because the sampling time is short, so that low power consumption can be realized. In addition, the probability that a malfunction will occur by performing sampling processing overlapping a plurality of slots can be extremely reduced.

The register 117 of the logic circuit section 119
The function of RSSI (reception field strength indication) can be realized by referring to the sum of squares (amplitude data) of 6 bits of each slot stored in. In the present embodiment, the bit extraction unit 153 extracts 6 bits out of 16 bits, but by reducing the number to 6 bits or less, it is possible to maintain the reception electric field determination capability corresponding to all general communication systems. Moreover, the circuit scale can be reduced.

When transmitting, the CPU 123 only needs to take out the 6-bit sum of squares (amplitude data) stored in the register 117 in order to detect the radio wave state for each slot. Can determine the slot to be used. As a result, it is possible to reduce the disconnection of the talk head and the call delay.

Conventionally, an element for performing squelch or RSSI has a basic function of a second intermediate frequency of 450 k.
Since the structure was realized in the IF signal band near Hz, the receiving system had to be a double superheterodyne structure. However, in the wireless communication terminal device of the present embodiment, even if the receiving system has a single superheterodyne structure, the squelch and the RSSI
Function can be realized. Therefore, the number of components for the receiving system can be reduced, and the mounting area can be reduced. Therefore, the size of the device can be reduced.

In this embodiment, as shown in FIG. 2, the root Nyquist filter (RNF) 115 is
Although it is provided after the D converter (ADC) 113,
Since the passage through the root Nyquist filter 115 requires a processing time according to its performance, a logic circuit section 119 may be provided in a stage preceding the root Nyquist filter 115. At this time, the processing can be speeded up. However,
Processing the signal after passing through the root Nyquist filter 115 can realize highly selective carrier detection.

In this embodiment, the case where one frame is composed of four slots has been described. Therefore, the register 117 is composed of four areas corresponding to each slot. For example, one frame is composed of six slots. If so, the register 117 is made up of six regions. If one frame is made up of six slots, it is possible to cope with a plurality of digital and analog systems in Japan.

The above is a description of reception. When the wireless communication terminal device performs transmission, the CPU 123 reads the 6-bit sum of squares (amplitude data) stored in the register 117 and determines the radio wave of which slot. Determine whether the condition is good. Therefore, the wireless communication terminal apparatus and the wireless communication method of the present embodiment transmit a transmission signal using the slot determined to be optimal by the CPU 123 without waiting for one frame time to obtain the radio wave state of each slot. be able to.

Further, in the present embodiment, a fixed data section near the center of a frame transmitted and received between terminals includes:
A sync word (synchronization word) is provided. Both wireless communication terminals performing direct communication can improve communication stability by establishing synchronization using a sync word included in a signal transmitted from the other party. When the modulation scheme is a multi-level modulation scheme such as 16QAM, the demodulated signal can have a plurality of levels, so it is difficult to make an accurate level determination depending on the radio wave condition. By including a signal and utilizing the signal, the level can be accurately determined.

[0076]

As described above, according to the wireless communication terminal device, the wireless control circuit, the wireless communication method, and the wireless communication program of the present invention, the receiving means (receiving step) converts the orthogonally modulated received signal into an orthogonal signal. The signal is demodulated to output an I signal and a Q signal, and A / D conversion means (A / D conversion step) A / D converts the I signal and the Q signal to quantize each signal to a predetermined number of bits. In the bit extracting means (bit extracting step), a part of bit information is respectively extracted from the digital I signal and the digital Q signal of a predetermined number of bits quantized by the A / D converting means, and the square sum calculating means (sum of squares) In the calculating step), the sum of squares of each bit information extracted by the bit extracting means is calculated, and in the threshold value determining means (threshold value determining step), Compares the resulting square sum with the threshold value by the sum calculating means determines the magnitude relation between the square sum with the threshold value, the communication processing / control unit (communication processing / control step)
In the above, communication processing or control is performed according to the determination result obtained by the threshold value determination means. In particular, it is desirable that the threshold is a desired amplitude level for determining the reception electric field.

Therefore, the presence or absence of communication can be determined based on the magnitude relationship between the sum of squares and the threshold value, and the threshold value can be set to a desired level. Even if the level is lowered, the squelch function can be realized.

The communication processing / control means (communication processing / control step) determines whether the threshold
If the sum of the squares is equal to or larger than the threshold, the apparatus is started up. Thus, when the squared value is less than the threshold,
That is, when there is no communication, the amount of power consumed by the communication processing / control means is suppressed, and the communication processing / control means is operated only when the square value is equal to or larger than the threshold value, that is, only when communication is being performed. Low power consumption of the device can be realized.

When the multiplexing method is TDMA (time division multiple access), mask information for selecting a slot to be used for communication is previously set in the storage means for each slot, and the threshold value judgment means Is sent to the communication processing / control means based on the mask information.
In this way, by masking an undesired slot using the mask information, it is possible to prevent the communication processing / control unit from being activated by communication unrelated to the terminal itself.
Therefore, low power consumption of the device can be realized.

When the multiplexing method is TDMA (Time Division Multiple Access), the receiving means is operated only for a predetermined time for each slot by the timer means, so that the receiving step is executed only for the predetermined time. I have. Therefore, the receiving means does not always operate in the standby state, but operates only at a predetermined timing and for a predetermined time for each slot to sample a received signal. Therefore, the power consumed by the receiving means can be reduced by the predetermined time, so that low power consumption can be realized.

Since the received electric field strength of each slot is measured based on the sum of squares calculated by the sum of squares calculating means (sum of squares calculation step), not only the squelch function can be obtained by using the sum of squares, but also , Reception electric field strength display (R
SSI) function can also be realized.

Further, the receiving means has a single superheterodyne structure. Conventionally, the receiving system had to have a double superheterodyne structure, but the single superheterodyne structure can also achieve the above-described effects. Therefore, the number of components for the receiving system can be reduced, and the mounting area can be reduced. As a result, the size of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a wireless communication terminal device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a wireless communication terminal device centering on a logic circuit unit.

FIG. 3 is an explanatory diagram illustrating a relationship between a bit and an amplitude of 16 bits extracted by a bit extraction unit.

FIG. 4 is a block diagram showing an example of a terminal used in a conventional wireless communication system.

FIG. 5 is an explanatory diagram illustrating a relationship between an out-of-band noise level and an electric field input level.

[Explanation of symbols]

 Reference Signs List 100 reception system (RX) 101 antenna 103 RF unit 105 intermediate frequency conversion unit (IF) 107 automatic gain control unit (AGC) 109 quadrature demodulator (IQ DEM) 111 oscillator (OSC) 113 A / D conversion unit (ADC) 115 Root Nyquist filter (RNF) 117 Register 118 OR operation unit 119 Logic circuit unit (GA) 121 DSP 123 CPU 151 Distribution unit 153 Bit extraction unit 155 Square sum calculation unit 157 Threshold judgment unit 159 Timer unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K028 HH00 KK12 LL12 RR02 SS04 SS14 SS23 5K052 BB02 CC06 DD02 EE13 FF13 FF18 GG19 GG25 GG48 GG54 GG57

Claims (23)

[Claims] 1. A receiving means for orthogonally demodulating a quadrature-modulated received signal to output an I signal and a Q signal, and A / D converting the I signal and the Q signal to convert each signal into a predetermined number of bits. A / D conversion means for quantizing, bit extraction means for extracting a part of bit information from the digital I signal and digital Q signal of a predetermined number of bits quantized by the A / D conversion means, respectively, A sum of squares calculating means for calculating a sum of squares of each bit information extracted by the extracting means; comparing the sum of squares obtained by the sum of squares calculating means with a threshold value; A digital system comprising: a threshold value judging unit for judging a magnitude relationship; and a communication processing / control unit for performing communication processing or control according to a judgment result obtained by the threshold value judging unit. Radio communication terminal device. 2. The wireless communication terminal device according to claim 1, wherein the threshold value is a desired amplitude level for the wireless communication terminal device to determine the presence or absence of a reception electric field. 3. The communication processing / control means is activated if the result of the determination by the threshold value determining means is that the sum of squares is equal to or greater than the threshold value, and the sum of squares is smaller than the threshold value. 3. The wireless communication terminal device according to claim 1, wherein a state of low power consumption is maintained. 4. The multiplexing method of the wireless communication terminal device is T
When a DMA (Time Division Multiple Access) is used, a storage means for storing mask information set in advance for each slot to select a slot to be used for communication is provided. The determination result obtained by the threshold value determination means is 3. The communication processing / control unit according to claim 1, wherein the information is sent to the communication processing / control unit based on the mask information stored in the storage unit.
Or the wireless communication terminal device according to 3. 5. When the determination result by the threshold value determination means is binary information of 0 or 1, and the mask information is also binary information of 0 or 1, the determination result and the mask information are provided for each slot. 5. The wireless communication terminal device according to claim 4, further comprising a logical sum operation unit for calculating a logical sum of the radio communication terminal and the wireless communication terminal. 6. The determination result obtained by the threshold value determination means is “1” when the sum of squares is equal to or greater than the threshold value, and “1” when the sum of squares is smaller than the threshold value. The wireless communication terminal apparatus according to claim 5, wherein the mask information is "0", "0" means a mask, and "1" means an unmask. 7. When the determination result sent to the communication processing / control means is a result obtained when the sum of squares is smaller than the threshold value for a predetermined number of slots continuously, the storage is performed. 7. The wireless communication terminal device according to claim 4, wherein the mask information stored in the means is automatically released. 8. The multiplexing method of said wireless communication terminal device is T
6. A system according to claim 1, further comprising timer means for operating said receiving means for a predetermined time at a predetermined timing for each slot when a DMA (Time Division Multiple Access) is used. , 6 or 7. 9. The communication processing / control unit according to claim 1, wherein the received electric field intensity of each slot is measured based on the sum of squares calculated by the sum of squares calculation unit. 9. The wireless communication terminal device according to 4, 5, 6, 7, or 8. 10. When the wireless communication terminal device starts transmission, the communication processing / control means selects an optimal slot based on the sum of squares calculated by the sum of squares calculation means. Claims 1, 2, 3, 4, 5, 6,
10. The wireless communication terminal device according to 7, 8, or 9. 11. The apparatus according to claim 1, wherein said receiving means has a single superheterodyne structure.
The wireless communication terminal device according to 3, 4, 5, 6, 7, 8, 9, or 10. 12. A receiving step of orthogonally demodulating a quadrature-modulated received signal to output an I signal and a Q signal; and performing A / D conversion on the I signal and the Q signal to convert each signal into a predetermined number of bits. An A / D conversion step of quantizing; a bit extraction step of extracting a part of bit information from the digital I signal and the digital Q signal of a predetermined number of bits quantized in the A / D conversion step; A square sum calculation step of calculating a sum of squares of each bit information extracted in the extraction step; comparing the square sum obtained in the square sum calculation step with a threshold value, and calculating the sum of the square sum and the threshold value A threshold value determining step of determining a magnitude relationship; a communication processing / control step of performing communication processing or control according to a determination result obtained in the threshold value determining step;
A digital wireless communication method comprising: 13. The apparatus according to claim 1, wherein the threshold value is a desired amplitude level for determining a reception electric field.
2. The wireless communication method according to 2. 14. The communication processing / control step activates communication processing / control means for performing communication processing or control if the sum of squares is equal to or greater than the threshold value as a result of the determination in the threshold value determination step. The communication processing / control means is kept in a state of low power consumption when the sum of squares is smaller than the threshold value.
3. The wireless communication method according to 3. 15. The multiplexing method of the wireless communication method is TD.
In the case of MA (Time Division Multiple Access), mask information for selecting a slot to be used for communication is set in advance for each slot, and the determination result obtained in the threshold determination step is the mask information The wireless communication method according to claim 12, 13 or 14, wherein the wireless communication method is sent to the communication processing / control means based on the following. 16. When the result of the threshold value determination step is binary information of 0 or 1 and the mask information is also binary information of 0 or 1, the determination result and the mask information are provided for each slot. 16. The wireless communication method according to claim 15, further comprising: a logical sum operation step of calculating a logical sum of the logical sum and 17. The determination result obtained in the threshold value determination step is “1” when the sum of squares is equal to or greater than the threshold value, and “1” when the sum of squares is smaller than the threshold value. 17. The wireless communication method according to claim 16, wherein the mask information is "0", "0" means a mask, and "1" means an unmask. 18. The method according to claim 18, wherein the determination result sent to the communication processing / control means is a result obtained when the sum of squares is smaller than the threshold value for a predetermined number of slots continuously. 18. The wireless communication method according to claim 15, wherein the information is automatically released. 19. The multiplexing method of the wireless communication method is TD.
2. The method according to claim 1, wherein the receiving step is performed for a predetermined time at a predetermined timing for each slot when the transmission is a MA (Time Division Multiple Access).
The wireless communication method according to 2, 13, 14, 15, 16, 17 or 18. 20. The apparatus according to claim 12, further comprising a receiving electric field intensity step of measuring a receiving electric field intensity of each slot based on the square sum obtained in the square sum calculating step. 16, 17, 18 or 19
The wireless communication method as described. 21. The method of claim 12, 13, 14, 15, 1
A wireless communication program for causing a computer to execute the wireless communication method according to 6, 17, 18, 19 or 20. 22. Bit extracting means for extracting a part of bit information from each of the I signal and Q signal quantized to a predetermined number of bits, and calculating a sum of squares of each bit information extracted by said bit extracting means. A sum of squares calculating means, and a threshold value judging means for comparing the sum of squares obtained by the sum of squares calculating means with a threshold value to determine a magnitude relationship between the sum of squares and the threshold value. A wireless control circuit characterized by the above. 23. When the multiplexing method is TDMA (Time Division Multiple Access), the storage means stores mask information preset for each slot in order to select a slot to be used for communication; 23. The wireless control circuit according to claim 22, wherein the determination result obtained by the determination unit is sent based on mask information stored in the storage unit.