JP2773699B2 - Carrier detection device in SS wireless communication - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spread spectrum (SS) for detecting a carrier of a direct spread system in a specific low power data radio communication system by using a carrier detection circuit of a frequency hopping system.
The present invention relates to a carrier detection device in wireless communication.

[0002]

2. Description of the Related Art Conventionally, in a specific low power data radio communication system employing SS radio communication, a frequency hopping (FH) type data radio communication device for performing data transmission at high speed, and a data transmission at low speed. Do direct diffusion (D
In some cases, both data wireless communication devices of the S) scheme are used. In this case, since the same frequency is used, it is determined whether or not the frequency is already used when transmitting. That is, carrier detection is performed so as not to interfere with data wireless communication that has already been performed, and data wireless communication without mutual interference is performed.

When performing data wireless communication by detecting a carrier in such SS wireless communication, the carrier detection is performed by a despreading circuit in the direct spreading method. For this despreading process, a SAW convalver or a digital matched filter is used.

In a data radio communication system using both the frequency hopping method and the direct spreading method in the same communication range (service area), if the spreading factor in the direct spreading method is sufficiently large, the frequency hopping method and the direct hopping method are used. Although there is no adverse effect between the two, the diffusion rate is, for example, 10
In the case of about twice, in the SS wireless communication device of the direct spreading method,
Since the influence of the SS wireless communication by the frequency hopping method cannot be excluded, communication disturbance occurs.

As a prior art relating to this type of carrier detection, Japanese Patent Application Laid-Open No. Hei 3-143037 discloses a "carrier sense level setting device for a cordless telephone".
JP-A-103230, "Carrier Sense Circuit". Japanese Patent Application Laid-Open No. H3-143037 discloses an example in which an individual detection level is set for a plurality of channels, a level variation between channels is absorbed, an erroneous search for an empty channel is reliably removed, and a level setting unit is used. Is smaller and lighter. Also, the example of JP-A-4-103230 is
With respect to a carrier input in a step-like manner, carrier detection is performed accurately and quickly within a certain time within a certain time, regardless of the level of the electric field strength of the carrier.

[0006]

However, in the former example of the above conventional example, both the frequency hopping method and the direct spreading method use the same communication range (service area).
For example, in order to simplify the device, when the carrier detection circuit of the frequency hopping system is shared and the carrier detection of the direct spreading system is performed, the reception carrier of the signal spread in a wide band according to the spreading code is used. The level becomes low, and it becomes difficult to detect the carrier by the direct diffusion method.

Therefore, both the frequency hopping scheme and the direct spreading scheme have the same communication range (service area).
In this case, separate carrier detection circuits for the frequency hopping scheme and the direct spreading scheme are required. In this case, a special electronic component, a SAW convalver, is required for despreading processing for carrier detection in the direct spreading method. Further, when a digital matched filter is used, the processing scale increases, and the scale of the apparatus increases.

In addition, it is difficult to construct a data radio communication system utilizing the characteristics of the frequency hopping system for performing high-speed data transmission and the direct spreading system for performing low-speed data transmission in the same communication range. It is. Furthermore, the latter publication reliably removes a vacant channel search error and performs carrier detection accurately and quickly, and has the same drawbacks as the former publication.

In other words, the former and latter examples are both
It is difficult to prevent an increase in the device scale, and it is also difficult to improve transmission efficiency and frequency use efficiency. Further, it is difficult to construct a data wireless communication system such as a wireless LAN that operates both the frequency hopping method and the direct spreading method in one communication range.

The present invention has been made to solve the above-mentioned problems in the prior art, and makes it possible to detect a carrier in a direct spreading system by diverting a carrier detecting circuit in a frequency hopping system, thereby increasing the size of the apparatus. And transmission efficiency and frequency (radio wave resource) utilization efficiency are improved, and
Provided is a carrier detection device in SS wireless communication that allows a degree of freedom in constructing a data wireless communication system such as a wireless LAN sharing a frequency hopping method and a direct spreading method.

[0011]

In order to achieve the above object, the present invention is directed to a carrier in SS radio communication in which a carrier detection circuit of a direct spreading system is used by diverting a carrier detection circuit of a frequency hopping system. A detection device, which receives at a plurality of frequencies inside and outside the spreading band of the direct spreading system, and detects a carrier level for each reception frequency, and a carrier level for each reception frequency detected by the reception detection unit. First storage means for storing, second storage means for previously storing respective carrier level patterns of a plurality of reception frequencies inside and outside the spreading band of the direct spreading method, and reception frequencies stored in the first storage means Each detected carrier level is compared with a carrier level pattern previously stored in the second storage means to determine whether a carrier has been detected. In which and a judging means for outputting a carrier detection judging signal.

According to a second aspect of the present invention, there is provided a carrier detection apparatus for SS radio communication, wherein a plurality of reception frequencies inside and outside a spread band in a direct spread system are frequency-converted as a receiving means according to the first aspect. And a detection means for detecting the intermediate frequency signal output by the reception processing circuit and outputting a detection signal having a level corresponding to a carrier level for each reception frequency.

According to a third aspect of the present invention, there is provided a carrier detection apparatus for SS radio communication,
A frequency conversion circuit that outputs an intermediate frequency signal obtained by frequency-converting a plurality of reception frequencies inside and outside the spreading band of the direct spreading method,
A local oscillation circuit that outputs a local oscillation signal for frequency conversion to a frequency conversion circuit, and a carrier that controls a local oscillation signal that is oscillated by the local oscillation circuit to sequentially set a plurality of reception frequencies inside and outside a spreading band of a direct spreading method. And a detection control circuit.

According to a fourth aspect of the present invention, there is provided a carrier detection apparatus for SS radio communication, wherein a carrier detection circuit of a direct spreading system is used by diverting a carrier detection circuit of a frequency hopping system.
A carrier detection device in S wireless communication, wherein the inside and outside of a spreading band of a direct spreading method are divided into a plurality of frequency bands,
Reception detection means for receiving each frequency band and detecting a carrier level for each reception frequency band; first storage means for storing a carrier level for each frequency band detected by the reception detection means; Second storage means for previously storing carrier level patterns of a plurality of frequency bands inside and outside the spread band, and detection carrier levels for each frequency band stored in the first storage means.
And a determination means for outputting a carrier detection determination signal for determining whether a carrier has been detected by comparing the carrier level pattern stored in advance in the storage means.

According to a fifth aspect of the present invention, there is provided a carrier detection apparatus for SS radio communication as a receiving means according to the fourth aspect, which amplifies a high frequency and converts the inside and outside of a spread band of a direct spread system to a low frequency, and performs frequency conversion. A reception processing circuit that divides the inside and outside of the spread band into a plurality of frequency bands and outputs the divided band.
A detection means for detecting a plurality of frequency band signals output by the reception processing circuit, and outputting a detection signal having a level corresponding to a carrier level for each of the plurality of frequency bands.

According to a sixth aspect of the present invention, there is provided a carrier detection apparatus for SS radio communication,
A frequency conversion circuit that converts a received frequency inside and outside of the direct-sequence spread band to a low frequency and outputs the same, a local oscillator circuit that outputs a local oscillation signal for frequency conversion to the frequency converter, and a spread band from the frequency converter circuit A plurality of bandpass filters for dividing and outputting the internal and external reception frequencies into a plurality of bands, and a plurality of bandpass filters are sequentially switched to select a plurality of frequency band signals inside and outside the spreading band of the direct spreading method. And a carrier detection control circuit for performing output control.

According to a seventh aspect of the present invention, there is provided a carrier detection apparatus for SS wireless communication, wherein the carrier detection control circuit according to the third or sixth aspect changes a transmission / reception frequency or a frequency band according to an input control signal, or spreads. Switching of a direct spreading method for changing a plurality of reception frequencies inside or outside the band or a plurality of reception frequency bands is performed.

The carrier detection apparatus in the SS wireless communication according to the first, second, third, and seventh aspects of the present invention uses a carrier detection circuit of a frequency hopping system, and performs carrier detection by the frequency hopping system. Switching of direct diffusion carrier detection.

In this case, a plurality of frequencies inside and outside the spread band in the direct spread system are sequentially received by controlling a local oscillation signal for frequency conversion, and each carrier level of the received frequency is detected. Then, the detected carrier level is compared with a carrier level pattern of a plurality of reception frequencies inside and outside of the spreading band of the direct spreading method stored in advance, and a carrier detection determination signal for determining whether the carrier has been detected is output. doing.

For example, when the data transmission rate is about 1 Mbps or 2 Mbps, in the carrier level pattern at each frequency inside and outside the spreading band in the direct spreading method, the detected carrier level shows an extremely low value at the frequency outside the spreading band, Since each frequency in the band shows a uniform level which is a characteristic of the direct spreading method, the carrier level pattern of the characteristic receiving frequency is compared with the carrier level of each receiving frequency, and the carrier detection by the direct spreading method is performed. It is determined whether or not it was completed.

Therefore, the carrier detection of the direct spreading system can be performed by diverting the carrier detection circuit of the conventional frequency hopping system. When the frequency hopping system and the direct spreading system are used in the same communication range (service area). , And separate carrier detection circuits for the frequency hopping method and the direct spreading method are not required, thereby preventing an increase in apparatus size.

Further, it is easy to construct a data radio communication system utilizing the characteristics of the frequency hopping method for performing high-speed data transmission and the direct spreading method for performing low-speed data transmission within the same communication range. As a result, the data transmission efficiency, the frequency (radio wave resource) utilization efficiency, and the degree of freedom in building a data wireless communication system are improved.

According to the fourth aspect of the present invention, there is provided a carrier detection apparatus for SS radio communication, wherein a plurality of frequency bands inside and outside a spreading band in a direct spreading system after conversion to a low frequency are sequentially applied to a plurality of bandpass filters. The carrier level is detected by switching, and the carrier level is detected for each of a plurality of frequency bands, and the carrier level is detected and compared with a carrier level pattern of a reception frequency band inside and outside the spreading band of the direct spreading method stored in advance. That is, the inside and outside of the spread band are divided into a plurality of frequency bands, and it is determined whether or not the carrier has been detected. Also in this case, the carrier detection circuit of the frequency hopping method is used, and the carrier detection by the frequency hopping method and the carrier detection by the direct spread method are switched.

Therefore, the increase in the scale of the device is prevented, and the transmission efficiency, the radio wave use efficiency, and the degree of freedom in constructing the data radio communication system are each improved.
Since carriers are detected inside and outside the spread band in a plurality of frequency bands, the carrier detection time is shortened.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a carrier detecting apparatus in SS wireless communication according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a first embodiment of a carrier detection device in SS wireless communication of the present invention. In the first embodiment, a carrier detection circuit of a frequency hopping system is used, and the operation of the frequency hopping system or the direct spreading system is selected.

In FIG. 1, an antenna Ant, a high-frequency amplifier 1 for amplifying a signal received from the antenna Ant, and an intermediate frequency (IF) signal obtained by frequency-converting the amplified high-frequency signal output from the high-frequency amplifier 1 are provided. And a frequency conversion circuit 2 for outputting. Further, a local oscillation circuit 3 for outputting a local oscillation signal Sa for determining a reception frequency (f1 to f11) to be described later inside and outside a spreading band in the direct spreading method to the frequency conversion circuit 2, and an output from the frequency conversion circuit 2 An intermediate frequency amplifying circuit 4 for amplifying and outputting an IF signal is provided.

Also, the amplified IF signal output from the intermediate frequency amplifier circuit 4 is detected, and a detection circuit 5 that outputs a detection signal Sb indicating a level for each reception frequency and a local oscillation signal Sa output from the local oscillation circuit 3 are used. There is provided a memory (1) 6 for storing the level of the detection signal Sb output from the detection circuit 5 corresponding to each carrier level of a plurality of reception frequencies inside and outside the spread band in the determined direct spreading method. Further, a memory (2) 7 for storing in advance carrier level patterns of reception frequencies (f1 to f11) inside and outside the spread band in the direct spreading method shown in FIG. 2 and outputting the carrier level pattern signal Sc is provided. I have.

Further, the carrier can be detected from the detected carrier level of the reception frequency stored in the memory (1) 6 and the carrier level pattern (signal Sc) shown in FIG. And a determination circuit 8 for determining whether or not the carrier detection signal Sd has been output. Further, there is provided a carrier detection control circuit 10 to which a switching control signal S1 for performing carrier detection in the frequency hopping scheme or a switching control signal S2 for performing carrier detection in the direct spreading scheme is input. When the switching control signal S1 is input, the carrier detection control circuit 10 outputs a control signal Se for instructing the local oscillation circuit 3 on the frequency of the local oscillation signal Sa for determining the reception frequency in the frequency hopping method. In addition, a control signal Se for instructing the local oscillation circuit 3 on the frequency of the local oscillation signal Sa for determining the reception frequency inside and outside the spread band in the direct spreading method is output by the switching control signal S2.

Next, the operation of the first embodiment will be described. FIG. 2 is a diagram for explaining a carrier detection level pattern (signal Sc) at reception frequencies (frequency f1 to f11) in the direct spreading method according to the first embodiment. In FIGS. 1 and 2, the data transmission rate is 1 Mbp.
In the case of about s or 2 Mbps, carrier level patterns at frequencies inside and outside the spreading band in the direct spreading method are as shown in FIG.

That is, frequencies f1, f2 and f10, f1 outside the spreading band in the carrier detection level pattern.
At 1, the detected carrier level shows a very low value. The frequencies f4, f5, f6, f7, and f8 in the spreading band show a uniform level which is a characteristic of the direct spreading method.
Hereinafter, the carrier detection in the direct spreading method is performed using the uniform level which is the feature.

First, when the switching control signal S1 for performing carrier detection in the frequency hopping system is input to the carrier detection control circuit 10, the carrier detection control circuit 10
Control signal Se for a sequence that varies by hopping the transmission / reception frequency by a known frequency hopping method from
Is transmitted to the local oscillation circuit 3, and carrier detection by the frequency hopping method is performed.

When the switching control signal S2 for performing carrier detection by the direct spreading method is input to the carrier detection control circuit 10, the carrier detection control circuit 10 supplies the local oscillation circuit 3 with the carrier detection level pattern (signal Sc) shown in FIG. ), The control signal Se is transmitted so as to transmit the local oscillation signal Sa having a frequency that receives the frequency f1 lower than the spread band. The received signal of the frequency f1 is input to the frequency conversion circuit 2 through the antenna Ant and the high frequency amplification circuit 1,
Here, the IF signal whose frequency has been converted is amplified by the intermediate frequency amplification circuit 4 and input to the detection circuit 5.

The level of the detection signal Sb output from the detection circuit 5 is stored in the memory (1) 6. That is, the detected carrier level of the frequency f1 with respect to the center frequency f0 outside the spreading band in the direct spreading method is stored in the memory (1) 6. Similarly, the detected carrier level of the frequency f2 outside the spreading band in the carrier detection level pattern shown in FIG. Further, the carrier levels of the frequencies f3, f4, f5, f6, f7, f8, and f9 in the spread band and the frequencies f10 and f11 outside the spread band are sequentially detected, and the detected carrier levels are stored in the memory (1) 6 To memorize.

Next, the determination circuit 8 takes in the detected carrier levels of the frequencies 1 to 11 stored in the memory (1) 6. At the same time, the determination is made by comparing with the carrier level pattern shown in FIG. 2 stored in the memory (2) 7, and the carrier detection determination signal Sd is output.

In this case, the frequencies f1, f2 and f outside the spreading band in the carrier detection level pattern shown in FIG.
At 10, f11, the detected carrier level shows an extremely low value. That is, the level becomes only noise. Also,
At frequencies f4, f5, f6, f7, and f8 within the spreading band, the level when a carrier is detected indicates a uniform relatively high level, which is a characteristic of the direct spreading method.
The frequencies f4, f5, f6, f7, f8 in this spread band
Is determined by the determination circuit 8 to determine whether or not carrier detection in the direct spreading method has been successfully performed.

As described above, in the first embodiment,
A frequency hopping type carrier detection circuit is diverted, and frequencies f1 to f11 inside and outside the spreading band in the direct spreading type are used.
Are sequentially received by controlling the local oscillation signal Sa, the carrier level is detected, and the carrier level is compared with the carrier level pattern to determine the detection of the carrier.

From this, the carrier detection circuit of the direct spread system can be detected by diverting the carrier detection circuit of the conventional frequency hopping system, and both the frequency hopping system and the direct spread system can have the same communication range (service area). In this case, separate carrier detection circuits for the frequency hopping method and the direct spreading method are not required. For example, SA which is a special component that performs carrier detection by the direct diffusion method
The need for a W convolution bar is eliminated, and a digital matched filter with a large processing scale is not required, thereby preventing an increase in the device scale.

Further, it is easy to construct a data radio communication system utilizing the characteristics of the frequency hopping method for performing high-speed data transmission and the direct spreading method for performing low-speed data transmission within the same communication range. Thus, the data transmission efficiency, the radio wave use efficiency, and the degree of freedom in constructing a data wireless communication system are improved.

Next, a second embodiment will be described. The second embodiment is configured to divert a carrier detection circuit of the frequency hopping system and perform carrier detection for each frequency band in the frequency hopping system or the direct spreading system, and perform carrier detection in the spread band in a short time. I'm trying to do it.

FIG. 3 is a block diagram showing the configuration of the second embodiment. In the second embodiment, similarly to the first embodiment, an antenna Ant, a high-frequency amplifier 1 for amplifying a signal received from the antenna Ant, and low-frequency conversion of an amplified high-frequency signal output from the high-frequency amplifier 1 are performed. A frequency conversion circuit 2 that outputs an intermediate frequency (IF) signal. In addition, a local oscillation signal S for converting the reception frequency inside and outside the spreading band in the direct spreading method to a low frequency.
and a local oscillation circuit 3 that outputs f to the frequency conversion circuit 2 and an intermediate frequency amplifier that amplifies and outputs band signals (IF signals) from band (number) 0 to band 4 extracted through a band-pass filter 9 described later. A circuit 4 is provided.

The band signals from band 0 to band 4 output from the intermediate frequency amplifier circuit 4 and extracted through a band pass filter 9 described later are detected, and a detection signal Sg indicating the detection level of each carrier is generated. The detection circuit 5 that outputs the signals and the detection corresponding to the carrier levels of bands 0 to 4 (reception frequency bands) inside and outside the spreading band in the direct spreading method determined by the local oscillation signal Sf output from the local oscillation circuit 3. And a memory (1) 6 for storing the level of the signal Sg. Also,
It has a memory (2) 7 for previously storing each carrier level pattern (signal Sh) in the reception frequency band (band 0 to band 4) in the direct spreading system shown in FIG.

Further, it is determined whether or not the carrier has been detected from the detected carrier level of the reception frequency stored in the memory (1) 6 and the carrier level pattern signal Sh stored in the memory (2) 7 in advance. A determination circuit 8 for outputting the carrier detection determination signal Si, and a frequency conversion circuit 2 and an intermediate frequency amplification circuit 4 are provided between the frequency conversion circuit 2 and the intermediate frequency amplifying circuit 4. ) Is provided.

The band-pass filter 9 has a band 0 having a center frequency f40 outside the spread band, a band 1 having a center frequency f41 within the spread band, a band 2 having a center frequency f42 within the spread band, and a center within the spread band. The filter (0) 9a, the filter (1) 9b, the filter (2) 9c, the filter (3) 9d, and the filter (4) that pass the band 3 of the frequency f43 and the band 4 of the center frequency f44 outside the spreading band, respectively.
9e.

A switching control signal S1 for carrier detection in the frequency hopping scheme or a switching control signal S2 for carrier detection in the direct spreading scheme is input. (The band 0 of the filter (0) 9a of the band-pass filter 9 to the band 4 of the filter (4) 9e) and outputs a switching signal Sj for selecting the band 4 from the band 0. Carrier detection control circuit 11
have.

Next, the operation of the second embodiment will be described. FIG. 4 is a diagram for explaining a carrier detection level pattern in a reception frequency band (band (number) 0 to band 4) in the direct spreading method according to the second embodiment. When the switching control signal S1 for performing carrier detection by the frequency hopping method is input to the carrier detection control circuit 11, a sequence for hopping and changing the transmission / reception frequency band by the known frequency hopping method from the carrier detection control circuit 11 Is transmitted to a band-pass filter (BPF) 9, and carrier detection is performed by the frequency hopping method.

When the switching control signal S2 for performing carrier detection by the direct spreading method is input to the carrier detection control circuit 11, the carrier detection control circuit 11 sends the switching signal Sj to the band-pass filter 9, and firstly the filter ( 0) 9a
Band 0 is selected.

In this case, the received signal is output to the frequency conversion circuit 2 through the antenna Ant and the high-frequency amplification circuit 1, and the IF signal converted to a low frequency is input to the band-pass filter 9. The frequency-converted IF signal is shown in FIG.
Has a frequency band inside and outside the spreading band shown in FIG. The band-pass filter 9 sequentially selects the filters (0) 9a to (4) 9e designated by the carrier detection control circuit 11, and amplifies the IF signal of band 0 from the selected filter (0) 9a to an intermediate frequency. The signal is amplified by the circuit 4 and input to the detection circuit 5.

The level of the detection signal Sg output from the detection circuit 5 is stored in the memory (1) 6. That is, the detected carrier levels of bands 0 to 4 inside and outside the spreading band in the direct spreading method are stored in the memory (1) 6. Similarly, the detected carrier level of band 1 in the carrier detection level pattern shown in FIG. Further, the carrier levels of bands 2, 3, and 4 are sequentially detected,
Each detected carrier level is stored in the memory (1) 6.

Next, the determination carrier 8 fetches the detected carrier levels from the band 0 to the band 4 stored in the memory (1) 6. At the same time, the determination is made by comparing with the carrier level pattern (signal Sh) shown in FIG. 4 stored in the memory (2) 7, and the carrier detection determination signal Si is output.

In this case, in the bands 0 and 4 outside the spreading band in the carrier detection level pattern shown in FIG.
The detected carrier level shows a very low value. That is,
The level is only noise. In the bands 1, 2 and 3 within the spreading band, the level when the carrier is detected is
In order to indicate a uniform level which is a feature of the direct spreading method, the determination circuit 8 determines that the level is the uniform level, which indicates that a carrier in the direct spreading method has been detected.

Thus, in the second embodiment,
The carrier detection circuit of the frequency hopping system is diverted, and the bands 0 to 4 inside and outside the spreading band in the direct spreading system are sequentially selected from the filter (0) 9a to the filter (4) 9e of the band-pass filter 9, and the carrier level is set. The carrier is detected and compared with the carrier level pattern to determine carrier detection.

As a result, similarly to the first embodiment, the carrier detection circuit of the direct frequency system can be detected by diverting the carrier detection circuit of the conventional frequency hopping system, thereby preventing an increase in the size of the apparatus and the data transmission. Efficiency, radio wave use efficiency, and the degree of freedom in building a data wireless communication system are each improved. At the same time, in the second embodiment, carrier detection is performed only in bands 0 to 4 inside and outside the spreading band, so that the spread detection is performed in comparison with the case where carrier detection is performed on a large number of reception frequencies as in the first embodiment. The carrier detection time within the band can be shortened.

[0053]

As is apparent from the above description, according to the carrier detection apparatus for SS radio communication according to the first, second, third, and seventh aspects of the present invention, a carrier detection circuit of a frequency hopping system is used, and , The carrier detection by the frequency hopping system or the carrier detection by the direct spread system is switched. In this case, a plurality of frequencies inside and outside the spread band in the direct spread system are sequentially received by controlling a local oscillation signal for frequency conversion, and each carrier level of the received frequency is detected. Then, the detected carrier level is compared with a carrier level pattern of a reception frequency inside and outside the spreading band of the direct spreading method stored in advance to output a carrier detection determination signal for determining whether or not the carrier has been detected. I have.

As a result, the carrier detection circuit of the direct spreading system can be detected by diverting the carrier detection circuit of the conventional frequency hopping system, and the frequency hopping system and the direct spreading system are used in the same communication range (service area). It will be possible to share the situation. Further, separate carrier detection circuits for the frequency hopping system and the direct spreading system are not required, and an increase in the scale of the apparatus can be prevented.

Further, it is easy to construct a data radio communication system utilizing the characteristics of the frequency hopping method for performing data transmission at high speed and the direct spreading method for performing data transmission at low speed within the same communication range. Thus, it becomes possible to obtain the data transmission efficiency, the frequency (radio wave resource) utilization efficiency, and the freedom of constructing the data radio communication system.

According to the carrier detection apparatus for SS radio communication according to the fourth, fifth, sixth and seventh aspects, a plurality of frequency bands inside and outside the spread band in the direct spread system after conversion into a low frequency are converted into a plurality of band-pass filters. Are sequentially switched and taken out, and the carrier level is detected, and it is determined whether or not the carrier has been detected by comparing with the carrier level pattern of the reception frequency band inside and outside the spreading band of the direct spreading method stored in advance. .

That is, the inside and outside of the spread band are divided into a plurality of frequency bands, and the carrier detection is determined. Also in this case, the carrier detection circuit of the frequency hopping method is used, and the carrier detection by the frequency hopping method and the carrier detection by the direct spread method are switched.

As a result, an increase in the scale of the device can be prevented, and the transmission efficiency, the radio wave use efficiency, and the degree of freedom in constructing a data radio communication system are each improved. further,
Since carriers are detected inside and outside the spread band in a plurality of frequency bands, the carrier detection time in the spread band can be shortened.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a carrier detection device in SS wireless communication of the present invention.

FIG. 2 is a diagram for explaining a carrier detection level pattern at a reception frequency in a direct spreading method according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a second embodiment.

FIG. 4 is a diagram for explaining a carrier detection level pattern in a reception frequency band in a direct spreading system according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High frequency amplifier circuit 2 Frequency conversion circuit 3 Local oscillation circuit 4 Intermediate frequency amplifier circuit 5 Detection circuit 6 Memory (1) 7 Memory (2) 8 Judgment circuit 9 Bandpass filter 9a-9e Filter (0)-Filter (4) 10 Carrier detection control circuit 11 Carrier detection control circuit Sa, Sf Local oscillation signal Sb, Sg Detection signal Sc, Sh Carrier level pattern signal Sd, Si Carrier detection determination signal Se Control signal Sj Switching signal S1, S2 Switching control signal

Claims (7)

(57) [Claims] An SS for performing carrier detection in a direct spreading system by diverting a carrier detection circuit in a frequency hopping system.
A carrier detection device for wireless communication, comprising receiving at a plurality of frequencies inside and outside a spreading band of a direct spreading method,
Reception detecting means for detecting a carrier level for each reception frequency; first storage means for storing a carrier level for each reception frequency detected by the reception detection means; and a plurality of receptions inside and outside the spreading band of the direct spreading system. A second storage unit for storing in advance carrier level patterns of respective frequencies; a detected carrier level for each reception frequency stored in the first storage unit; and a storage in advance in the second storage unit. Determining means for comparing a carrier level pattern and outputting a carrier detection determination signal for determining whether a carrier has been detected or not, a carrier detection apparatus for SS wireless communication. 2. A reception processing circuit according to claim 1, wherein the reception processing circuit amplifies a high frequency signal and outputs an intermediate frequency signal obtained by frequency-converting a plurality of reception frequencies inside and outside a spreading band in a direct spreading method. A carrier detection device for SS wireless communication, comprising: a detection unit that detects an intermediate frequency signal output by a reception processing circuit and outputs a detection signal having a level corresponding to a carrier level for each reception frequency. 3. A reception processing circuit according to claim 2, wherein: a frequency conversion circuit for outputting an intermediate frequency signal obtained by frequency-converting a plurality of reception frequencies inside and outside a spreading band of a direct spreading system; A local oscillation circuit that outputs a local oscillation signal of: and a carrier detection control circuit that controls a local oscillation signal that is oscillated by the local oscillation circuit in order to sequentially set a plurality of reception frequencies inside and outside a spreading band of a direct spreading method. A carrier detection device for SS wireless communication, comprising: 4. An SS for performing carrier detection in a direct spreading system by using a carrier detection circuit in a frequency hopping system.
A carrier detection device in wireless communication, comprising: a reception detection unit configured to receive a frequency band divided into a plurality of frequency bands inside and outside a spread band of a direct spreading method, and to detect a carrier level for each reception frequency band; First storage means for storing a carrier level for each frequency band detected by the reception detection means, and second storage means for previously storing carrier level patterns of a plurality of frequency bands inside and outside the spreading band of the direct spreading method. A carrier which determines whether a carrier has been detected by comparing a detected carrier level for each frequency band stored in the first storage means with a carrier level pattern stored in advance in the second storage means; A determination means for outputting a detection determination signal, comprising: a carrier detection apparatus in SS wireless communication. 5. The receiving means according to claim 4, wherein high-frequency amplification and conversion of the inside and outside of the spread band of the direct-spreading method to a low frequency and division of the inside and outside of the frequency-converted spread band into a plurality of frequency bands are performed. A reception processing circuit that detects the plurality of frequency band signals output by the reception processing circuit, and outputs a detection signal having a level corresponding to a carrier level for each of the plurality of frequency bands. A carrier detection device in SS wireless communication, characterized by: 6. A reception processing circuit according to claim 5, wherein: a frequency conversion circuit for converting a reception frequency inside and outside of a spread band of a direct spreading system to a low frequency and outputting the same; and a local oscillation for frequency conversion to the frequency conversion circuit. A local oscillation circuit that outputs a signal, a plurality of bandpass filters for dividing and outputting reception frequencies inside and outside the spread band from the frequency conversion circuit into a plurality of bands, and sequentially switching the plurality of bandpass filters. And a carrier detection control circuit for performing control to select and output a plurality of frequency band signals inside and outside of a direct-spreading spread band, and a carrier detection device in SS wireless communication. 7. The carrier detection control circuit according to claim 3, wherein the carrier detection control circuit changes the frequency of transmission and reception or a frequency band by an input control signal, or a plurality of reception frequencies or a plurality of receptions inside and outside a spread band. A carrier detection apparatus in SS wireless communication, wherein switching of a direct spreading method for changing a frequency band is performed.