JP2000013292A - Radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible radio communication method. SOLUTION: A transmission station makes communication by increasing transmission power till a transmission output reaches a maximum transmission output as the transmission station is apart from a reception station by transmission output control. Figure shows increase in the transmission output from the transmission station to keep channel quality when the distance between the transmission station and the reception station increases. When the transmission output from the transmission station reaches the maximum output, the transmission station makes transmission through two branches consisting of the existing carrier and of an additional carrier apart by a correlation band width or over from the existing carrier. The reception station makes diversity reception. When the reception station moves in a direction to increase the distance from the transmission station, the transmission station increases a further additional carrier apart by the additional correlation band width or over as shown in the figure and makes transmission by using three carriers. The reception station uses the three carriers to conduct diversity reception.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to wireless communication. In particular, the present invention relates to performing higher-speed transmission and multiplexing using existing facilities in mobile communication.

[0002]

2. Description of the Related Art Today, various services using wireless communication are rapidly spreading.

There is a need for wireless communication equipment capable of accommodating increasing network traffic and increasing wireless communication users. In addition, wireless communication equipment that can flexibly accommodate non-telephone traffic in data transmission and the like is required.

[0004] To handle the rapidly increasing traffic, more efficient radio channel access is required. For example, an increase in frequency utilization efficiency due to high efficiency modulation. Also, in order to accommodate non-telephone traffic flexibly, wireless channel access capable of higher-speed transmission is required. For example, it is a multi-rate transmission method in the CDMA system.

Changing the once designed and installed radio line and its equipment to a modulation scheme different from the design and a higher transmission rate requires radio communication such as required Eb / No, required CIR, same frequency repetition distance, transmission loss and the like. It is not easy, resulting in changing the parameters of communication system design.

For example, when higher-speed transmission is performed using existing wireless communication equipment, the following method is conceivable.

(1) Use high efficiency modulation.

(2) The transmission band is expanded while keeping the modulation used.

However, regarding (1), the required E
b / No and required CIR changes, existing equipment and designs are not immediately applicable. Further, the frequency use efficiency can be increased as compared with the existing system.

Regarding (2), the design of the existing radio line can be applied, but the equipment needs to be modified by changing the transmission bandwidth. Further, the frequency use efficiency is lower than that of the existing system.

[0011] As in this example, there is a need for a wireless communication method that can utilize existing wireless communication line designs and wireless communication equipment as much as possible without reducing the frequency utilization efficiency of the existing system.

[0012]

The conventional radio communication line design method does not assume that the radio communication method such as the modulation method is changed after the construction of the radio equipment. Further, from the viewpoint of constructing an economical wireless communication system, current wireless communication equipment is optimized for a wireless communication system to be used. It is desired that the frequency use efficiency is equal to or higher than that of the existing system. From the above viewpoints, the method using the high-efficiency modulation is easier to apply to the existing method than the method for expanding the transmission band. The problem to be solved by the present invention is to provide a radio communication method which is flexible with respect to the conventional radio channel design and radio communication equipment without reducing the frequency use efficiency even with such high efficiency modulation. To provide.

[0013]

The present invention solves the above-mentioned problem by increasing the number of radio channels according to the transmission output control of the transmitting station. That is, in order to solve the above problems, the present invention solves the following.

According to a first aspect of the present invention, when it is determined that a preset condition has been reached in a wireless communication method between a transmitting station performing transmission output control with the receiving station and the receiving station. , N (N is a natural number of 1 or more) additional radio channels, and diversity reception is performed at the receiving station using the already used channels and the N channels.

According to a second aspect of the present invention, in the wireless communication method according to the first aspect, the condition is a predetermined transmission output, and the third aspect of the present invention provides the wireless communication method according to the first aspect. Wherein the condition is that the bit error rate has deteriorated from a predetermined bit error rate.

The invention described in claim 4 is the first to third aspects of the present invention.
In the wireless communication method according to any one of the first to third aspects, the line is configured by a carrier, and a frequency interval between each of the already used carrier and the added N carriers is equal to or larger than the correlation bandwidth, and the carrier and the N carriers And performs frequency diversity reception at the receiving station.

According to a fifth aspect of the present invention, in the wireless communication method according to the fourth aspect, a frequency interval between the already used carrier and the N carriers is set near a correlation bandwidth. And

By setting the frequency interval of the carrier waves to be equal to or larger than the correlation bandwidth or close to the correlation band, each of the carrier waves to be used becomes almost uncorrelated. Therefore, it is possible to perform uncorrelated diversity reception.

According to a sixth aspect of the present invention, in the wireless communication method according to the fourth or fifth aspect, a plurality of carrier waves used by the transmitting station are transmitted in different time zones.

According to this configuration, the transmitting station uses one carrier wave, so that the load on the required capacity of the wireless device, particularly the transmission power amplifier, can be reduced.

The invention according to claim 7 is the invention according to claims 1 to 3
In any of the wireless communication methods described above, the communication between the transmitting station and the receiving station is time-divided to perform wireless communication, and the line is formed of time slots, and the time slots already used and the N number of time slots are used. Set the time slot spacing to about twice the maximum Doppler frequency,
Time diversity reception is performed at a receiving station using the time slot and the N time slots.

According to an eighth aspect of the present invention, in the wireless communication method between the transmitting station and the receiving station that is performing transmission output control between the receiving station and the receiving station, it is determined that the preset transmitting output has been reached. At this time, the number of N (N is a natural number of 1 or more) antennas is set at the receiving station, and the interval between the already used receiving station antenna and each of the N antennas is set to about 程度 of the wavelength of the carrier frequency. And setting, and performing space diversity reception at a receiving station using the antenna and the N antennas.

According to a ninth aspect of the present invention, in the wireless communication method between the transmitting station and the receiving station that is performing transmission output control between the receiving station and the receiving station, when the code error rate becomes lower than a preset code error rate. The number of N antennas (N is a natural number of 1 or more) is set at the receiving station, and the interval between the antenna of the receiving station already used and each of the N antennas is set to about 程度 of the frequency frequency wavelength. , The antenna and the N
It is characterized in that spatial diversity reception is performed at a receiving station using the number of antennas.

By setting the interval between the receiving antennas to be about half the wavelength of the carrier frequency, each of the plurality of receiving antennas becomes almost uncorrelated.

According to a tenth aspect of the present invention, in the wireless communication method according to any one of the first to seventh aspects, the receiving station sets N (N
The antenna is characterized in that spatial diversity reception is also performed using antennas having different natural numbers (one or more).

[0026] The eleventh aspect of the present invention is the first aspect of the present invention.
0, wherein quadrature amplitude modulation is used as a modulation method, and the invention according to claim 12 uses phase shift keying as a modulation method.
The invention according to the third aspect uses frequency shift keying as a modulation scheme, and the invention according to claim 14 is characterized in that coded modulation is used as a modulation scheme.

In the present invention, quadrature amplitude modulation (Quadrat
ure Amplitude Modulation (QAM), phase shift keying (Phase Shift Keying: PSK), frequency shift keying (Frequency Shift Keying: FSK), high efficiency modulation such as coded modulation (Coded Modulation) can be applied.

The invention according to claim 15 is the invention according to claims 1 to 1
0, the modulation method is 1
Six-level quadrature amplitude modulation is performed, and when a preset condition is reached, two-branch reception to four-branch reception are performed.

According to a sixteenth aspect of the present invention, in the wireless communication method according to the fifteenth aspect, two-branch reception is two-space diversity reception, and four-branch reception is two-space diversity reception and two-frequency diversity reception. I do.

As described above, the present invention provides the required Eb / No
And when the required CIR is not satisfied and the transmission power is the maximum, by adaptively combining transmission diversity by the transmitting station and diversity reception by the receiving station,
With the limited transmission output, the service area and line quality set by the existing wireless communication line design and wireless communication equipment can be applied as much as possible. This makes it possible to provide a wireless device and a wireless communication method that are economically excellent and have expandability.

[0031]

Embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) In the first embodiment, when it is determined that the transmitting station controlling the transmission output with the receiving station has reached a certain transmission output, N stations (where N is one or more) are used. A new carrier (natural number) is set. The frequency interval of the newly set carrier is set to be equal to or larger than the correlation bandwidth. This makes each of the used carriers substantially uncorrelated. Using the carrier already used and the newly set carrier,
The receiving station performs frequency diversity reception. In this way, by dynamically increasing the number of transmission branches, it is possible to maintain a constant line quality without increasing the transmission output for each carrier.

The first embodiment will be described in detail with reference to FIGS.

FIG. 1 is a graph showing the relationship between the transmission output and the distance between wireless stations. FIG. 2 is a diagram for explaining the arrangement of carrier waves in the wireless communication according to the present embodiment. FIG.
It is a figure showing the relation of an area. In the graph of FIG.
The vertical axis indicates the transmission output, and the horizontal axis indicates the distance between the wireless stations. As the distance between the wireless stations increases, the transmission loss increases. In the first embodiment shown in FIGS. 1 to 3, the modulation scheme is 16QAM.

In FIG. 3, the transmitting station 10 and the receiving station 20
Communicates using the existing carrier when the receiving station 20 is in the one-branch receiving area. At this time, for example, by controlling the transmission output from the receiving station 20, the transmitting station 10
Is the transmission station 1 until the transmission output reaches the maximum transmission output.
When the distance between 0 and the receiving station 20 increases, the transmission power is increased and communication is performed. This is shown in FIG. In FIG.
As the distance between the transmitting station 10 and the receiving station 20 increases, the transmission output from the transmitting station 10 increases to maintain the quality of the line. Then, when the transmission output from the transmission station 10 reaches the maximum output, the transmission station 10 as shown in FIG.
An additional carrier separated by more than the correlation bandwidth is added to the existing carrier and transmitted as two branches. The receiving station 20 performs diversity reception. Since the number of carriers for diversity is increasing, the transmission power required for each carrier to maintain the line quality is reduced. Therefore, when the transmitting station 10 performs two-branch transmission, the transmission output of each transmission carrier is reduced as shown in FIG. 1 by the transmission output control from the receiving station 20. This means that the receiving station 20 is in the two-branch receiving area shown in FIG. The receiving station 20 is the transmitting station 1
Moving in a direction to further increase the distance from 0, the transmitting station 10 increases the number of additional carriers separated by more than the additional correlation bandwidth and transmits using three carriers as shown in FIG. The receiving station 20 performs diversity reception using these three carriers. At this time, the transmission output required to maintain the line quality is reduced. The receiving station 20 corresponds to 3 in FIG.
You are in the branch reception area.

As described above, the number of diversity branches is selected so as to be always equal to or less than the limited maximum transmission output. The additional carriers that make up each branch are separated by more than the related bandwidth as shown in FIG. FIG. 3 shows a service area of wireless communication. The area where one branch is received is closest to the transmitting station, and the distance between the transmitting station and the receiving station increases as the number of branches increases. 1 to 3, a maximum of three branches are received, and a service area equivalent to a conventional service area based on, for example, QPSK is secured. At this time, as shown in FIG. 1, the maximum transmission output is always the same as the conventional wireless communication method.

Therefore, it is not necessary to change the parameters of the existing wireless communication line such as an increase in co-channel interference by the wireless communication method according to the present invention. Further, by using a high-efficiency modulation such as 16QAM, it is possible to increase the frequency use efficiency as compared with the existing system.

The frequency interval of the carrier shown in FIG. 2 can be set near the correlation bandwidth. This is shown in FIG. This makes each of the used carriers substantially uncorrelated.

(Embodiment 2) In the embodiment 2, when the transmission output from the transmitting station that controls the transmission output with the receiving station reaches the maximum output, N (N is (1 or more natural number) receiving antennas are newly set. The interval between the receiving antennas is set to about 1/2 of the wavelength of the carrier frequency.

As a result, the plurality of receiving antennas are substantially uncorrelated. Spatial diversity reception is performed at the receiving station using the already used receiving antenna and the newly set receiving antenna.

This embodiment will be described in detail with reference to FIGS. The modulation method used here is 16QAM
And FIG. 5 shows a frequency arrangement in the second embodiment.
As can be seen from the frequency arrangement of FIG. 5, only the existing carrier is used. FIG. 6 shows a service area of wireless communication.
As shown in FIG. 6, the receiving station 20 of the present embodiment has a plurality of receiving antennas. The interval between the receiving antennas is set to about 1/2 of the wavelength of the carrier frequency. Thereby, each of the plurality of receiving antennas becomes almost uncorrelated.
Here, an example in which three receiving antennas are used is shown.
In FIG. 6, the receiving station 20 increases the number of additional receiving antennas according to the distance from the transmitting station 10. Transmitting station 10
In an area close to, the receiving station 20 uses one receiving antenna to perform one-branch reception using transmission output control until the maximum transmission output is reached. The receiving station 20 performs two-branch spatial diversity using the two receiving antennas in the next area. When the transmission using the spatial diversity of two branches reaches the maximum output, spatial diversity of three branches is performed in an area farther than that. Diversity reception at this time (reception using multiple branches)
The relationship between the transmission output and the distance between the wireless stations is the same as in FIG.

As described above, the receiving station 20 of the present embodiment
After the transmission output of the transmitting station 10 reaches the maximum, a service area equivalent to the conventional one by, for example, QPSK is secured by spatial diversity reception.

(Embodiment 3) In the third embodiment, when the transmission of a transmitting station that controls transmission output with a receiving station reaches a certain transmission output, N transmissions (N is a natural number of 1 or more) are performed. A new time slot is set. The time interval of each time slot is set to about twice the maximum Doppler frequency. As a result, the intervals of the plurality of time slots become almost uncorrelated. The time slot already used and the newly set time slot
Time diversity reception is performed at the receiving station using the slots. This time diversity maintains the quality of the line.

FIG. 7 shows the positional relationship of the time slots according to the present embodiment. The modulation method at this time is 16QAM. The time position shown in FIG. 7 is the maximum Doppler frequency of 2
The time interval is set to about one-tenth. Since each time slot is independent as shown in FIG. 7, three-branch reception is possible. Therefore, Embodiment 1 or 2
Similarly to the above, when the transmission output in the reception by one branch using the existing time slot becomes the maximum, the line quality is maintained by the time diversity reception of two branches or three branches using the additional time slot. be able to. The state of diversity reception at this time is shown in FIG.
And FIG.

As described above, the present embodiment secures a service area equivalent to that of the related art by using, for example, QPSK by time diversity reception.

(Embodiment 4) Embodiment 4 is a combination of Embodiments 1 and 2 described above.
Therefore, when a certain transmission output is reached, the receiving station uses N (N is a natural number of 1 or more) receiving antennas set at a distance of about half the carrier frequency. For this space diversity, N (N is a natural number of 1 or more) carrier waves can be newly set. Using the carrier already used and the newly set carrier,
The receiving station performs frequency diversity reception. This allows
The receiving station performs spatial and frequency diversity reception.

The fourth embodiment will be specifically described with reference to FIGS. FIG. 8 shows the frequency arrangement. The carrier frequency intervals are separated by more than the correlation bandwidth. FIG. 9 shows a service area of wireless communication. The modulation method used here is 16QAM. As shown in FIG. 9, the receiving station 20 uses a plurality of receiving antennas located at a distance of a half of the wavelength of the carrier frequency. With this receiving antenna and carrier, diversity reception corresponding to a maximum of 9 branches (3 branches in space × 3 branches in carrier) is possible.

As described above, by the frequency and space diversity reception, a service area equivalent to the conventional one by, for example, QPSK is secured.

The above-mentioned additional carrier frequency intervals may be separated only by the vicinity of the correlation bandwidth.

(Embodiment 5) Embodiment 5 is a combination of Embodiment 3 (time diversity) and Embodiment 2 (space diversity). Therefore, the receiving station of the third embodiment further uses N (N is a natural number of 1 or more) receiving antennas set at a distance of about １ ／ of the carrier frequency. As a result, the receiving station performs time and space diversity reception.

More specifically, from the transmitting station, when the output exceeds the maximum output, as shown in the time slot arrangement of FIG. 7, the time slot interval is about one half of the maximum Doppler frequency. At time intervals, additional time slots are sent. As shown in FIG. 6, the receiving station has three receiving antennas set at a distance of about half the wavelength of the carrier frequency. For this reason, in the present embodiment, it is possible to perform diversity reception corresponding to a maximum of nine branches (time diversity 3 × space diversity 3).

(Embodiment 6) In Embodiment 6, a time element is added to Embodiment 1 (frequency diversity) described above.
This is a simplified configuration of the transmitting station.

FIG. 10 shows the frequency (FIG. 10A) and time (FIG. 10B) used for transmission and reception in the sixth embodiment.
The following shows the arrangement. The modulation method is 16QAM. Embodiment 6 is characterized in that a plurality of carriers are transmitted at different times. Therefore, the sixth embodiment has the effect of the frequency diversity of the first embodiment and the effect that the radio circuit can be more easily designed by transmitting a plurality of carriers at different times. The interval between the added carriers may be near the correlation bandwidth.

(Regarding Modulation System Used) In the first to sixth embodiments, the modulation system used for transmission / reception is 16
QAM (16-level quadrature modulation), but more multi-level QAM
The present invention also has the same effect.

Similarly, the same effect can be obtained by using PSK (phase shift keying or FSK (frequency shift keying)) as the modulation method used for transmission and reception.

Similarly, the same effect can be obtained when the modulation method used for transmission and reception is coded modulation.

(Control Based on Error Rate) First to Third Embodiments
In No. 6, the diversity reception is controlled by the transmission output. However, control can also be performed based on the bit error rate of the received signal. FIG. 11 shows the relationship between the bit error rate of a received signal and the distance between wireless stations. The transmission and reception conditions shown in FIG. 11 are such that the transmission output of the wireless station is constant and the code error rate is 10 ⁻² or less. At this time, when the code error rate set in advance is degraded, a predetermined error rate or less can be achieved by increasing the number of branches.

Such control based on the bit error rate of the received signal can be applied commonly to the frequency diversity, space diversity, time diversity and combinations thereof described in the first to seventh embodiments. .

(Exemplary Configuration of Transceiver with Multiple Carrier Waves) FIG. 12 shows an exemplary configuration of a radio station used in the first embodiment and the like.

The radio station shown in FIG. 12 has two sets of transmitting / receiving sections in the radio section.

The first receiver and the second receiver respectively include high-frequency amplifiers 112 and 122, reception mixers 114 and 124,
It is composed of intermediate amplifiers 116 and 126 and demodulators 118 and 128, and receives radio channels of different frequencies to generate baseband signals. The first transmitting unit and the second
The transmission unit includes modulators 136 and 146, transmission mixer 134,
144, and transmission power amplifiers 132 and 142.
The first transmission unit and the second transmission unit include a baseband processing unit 1
The transmission signals from the transmissions 50 are transmitted on radio channels of different frequencies. The frequency synthesizer 103 includes reception mixers 114 and 124 of the first and second reception units 110 and 120,
Then, corresponding frequencies are sent to the transmission mixers 134 and 144 of the first and second transmission units 130 and 140, and the respective reception frequencies and transmission frequencies are determined.

The reception signal from the radio section and the transmission signal to the radio section are processed by the reception signal processing circuit 152 and the transmission signal processing circuit 154 of the baseband signal processing section 150. The signal from the reception signal processing circuit 152 is output to the receiver 170
To the user of the mobile device. Signals from the transmitter 180 and the like are processed by the transmission signal processing circuit 154 and sent to the wireless unit. The control unit includes a control circuit 160 including a display, keys 190, a CPU, and the like, and controls the baseband signal processing unit 150 and the wireless unit.

As described above, the transmission and reception can be performed using a plurality of carriers (two frequencies in FIG. 12), and diversity reception can be performed by simultaneously receiving these plurality of carriers. Note that the above-described wireless station has a configuration capable of transmitting a plurality of carrier waves, but is not necessarily required for a wireless station that does not need to transmit a plurality of carrier waves (for example, a mobile station in mobile communication).

(Control Example of Line Setting) FIG. 13 is a diagram showing one example using the above-described fourth embodiment (frequency and space diversity).
16Q from diversity reception by 6QAM2 branch
It is the flowchart explaining the specific control of the receiving side when switching to the diversity reception of the AM4 branch. This processing can be realized using, for example, the configuration of the wireless station shown in FIG.

In the processing shown in FIG. 13, diversity reception in the fourth embodiment will be specifically described using mobile radio communication on the downlink when the transmitting station is a base station and the receiving station is a mobile station.

In FIG. 13, when the mobile station attempts to set a line, it identifies the area where the mobile station is located, specifies the base station (S105), and attempts to set a line using an available line. At this time, the mobile station measures the Eb / NO and CIR of the line to be set, and obtains a predetermined Eb / N
o and CIR (S110). If the quality of the line to be set is sufficiently high, the line is set as it is (S115). In FIG. 12, two spatial diversity receptions are always performed at the mobile station.

When the quality of the line is not good, transmission output control is performed. For this purpose, a command is transmitted from the mobile station to the base station to increase the transmission output (S120). This process is performed until a sufficient line quality is obtained ("No" in S135), and if it is obtained ("Yes" in S135), the line is set (S140).

Now, when the mobile station comes to the cell edge, on the downlink, the base station transmits to the mobile station with the maximum transmission power ("Yes" in S130). The mobile station searches for an additional free wireless channel in order to perform wireless communication with the base station even at the cell edge (S155).

After detecting a free radio channel, the mobile station applies to the base station with which the mobile station is currently talking to use the radio channel detected by the mobile station. When there is no particular problem in using the wireless channel requested by the mobile station, the base station sets up a wireless communication line with the mobile station (S160). The wireless communication line to be set is a wireless channel of a different carrier in the first embodiment. As a result, the mobile station can use the carrier already used and the newly set carrier.
The mobile station performs combined reception of the plurality of received wireless channels. The combined reception at this time is four-branch diversity because two spatial diversity and two frequency diversity are performed. The quality of the additional line is also checked (S165), and if it is not sufficient, transmission output control is performed (S175, S180, S18).
5). If the line quality is not sufficient even at the maximum transmission output after performing the transmission output control ("Yes" in S180), the line setting cannot be set (S190).

The determination as to whether the transmission power is the maximum transmission power may be made based on the fact that the quality of the line is not improved even if the command for increasing the transmission power is transmitted.

As a result, 16QAM which is high-efficiency modulation
, It is possible to prevent a decrease in cell radius due to an increase in required Eb / NO and required CIR.

In FIG. 12, it has been described that the line is defined by the carrier as described in the fourth embodiment. However, as described in the other embodiments, the improvement of the reception quality by the diversity may be such that the line is defined by a time slot, a spreading code, or a combination thereof. Also in this case, the control can be performed in the same manner as the control shown in FIG. The quality may be improved not only by diversity due to an increase in the number of lines but also by spatial diversity due to an increase in the number of reception antennas.

As described above, according to the radio communication method of the present invention, the required Eb / NO and the required C
By selecting a new wireless channel when the IR cannot be satisfied, it is possible to provide a wireless communication method for performing wireless communication by simultaneously using the existing wireless channel and the newly set wireless channel.

Further, by performing diversity reception at the receiving station by simultaneously using a plurality of radio channels, the transmission output of the base station can be reduced, and the required Eb / NO and the required CIR at the mobile station can be satisfied.

[0075]

The present invention has the following effects.

(1) Wireless communication can be performed over a longer distance within a limited transmission power range.

(2) High-speed transmission or high-quality transmission can be performed using existing equipment.

(3) In high-speed transmission, wireless communication can be performed with lower power.

(4) The design parameters of the current radio system such as cell equipment can be used.

(5) Since the conventional wireless communication equipment and line design can be applied, a more economical wireless communication system can be constructed.

(6) High compatibility with existing wireless communication systems.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a transmission output and a distance between wireless stations.

FIG. 2 is a diagram illustrating an arrangement of carrier waves in wireless communication according to the first embodiment.

FIG. 3 is a diagram illustrating a relationship between a transmitting station (base station) and a receiving station (mobile station).

FIG. 4 is a diagram illustrating another arrangement of carrier waves in wireless communication.

FIG. 5 is a diagram illustrating an arrangement of carrier waves in wireless communication according to a second embodiment.

FIG. 6 is a diagram illustrating a relationship between a transmitting station (base station) and a receiving station (mobile station).

FIG. 7 is a diagram illustrating an arrangement of time slots in wireless communication according to a third embodiment.

FIG. 8 is a diagram illustrating an arrangement of the number of carriers in wireless communication according to a fourth embodiment.

FIG. 9 is a diagram illustrating a relationship between a transmitting station (base station) and a receiving station (mobile station) according to the fourth embodiment.

FIG. 10 is a diagram illustrating an arrangement of the number of carriers in wireless communication according to a sixth embodiment.

FIG. 11 is a graph illustrating a relationship between an error rate of a received signal and a distance between wireless stations.

FIG. 12 is a block diagram illustrating an example of a configuration of a wireless station.

FIG. 13 is a flowchart illustrating an example of control.

DESCRIPTION OF SYMBOLS 10 transmitting station 20 receiving station 103 frequency synthesizer 110, 120 receiving unit 112, 122 high frequency amplifier 114, 124 receiving mixer 116, 126 intermediate amplifier 118, 128 demodulator 130, 140 transmitting unit 132, 142 transmission power amplifier 134, 144 Transmit mixer 136, 146 Modulator 150 Baseband signal processing unit 152 Receive signal processing circuit 154 Transmit signal processing circuit 160 Control circuit 170 Handset 180 Transmitter 190 Display key

Claims (16)

[Claims] In a wireless communication method between a transmitting station performing transmission output control with the receiving station and the receiving station, when it is determined that a preset condition has been reached, N (N: A wireless communication method comprising: setting an additional wireless line of one or more natural numbers); and performing diversity reception at a receiving station using the already used line and the N lines. 2. The wireless communication method according to claim 1, wherein the condition is a predetermined transmission output. 3. The wireless communication method according to claim 1, wherein the condition is that the bit error rate is lower than a predetermined bit error rate. 4. The wireless communication method according to claim 1, wherein the line is constituted by a carrier, and the frequency interval between the carrier already used and the N carriers to be added is set to be equal to or larger than the correlation bandwidth. A wireless communication method comprising: performing frequency diversity reception at a receiving station using the carrier and the N carriers. 5. The wireless communication method according to claim 4, wherein a frequency interval between the already used carrier and the N carriers is set near a correlation bandwidth. 6. The wireless communication method according to claim 4, wherein a plurality of carriers used by the transmitting station are transmitted in different time zones. 7. The wireless communication method according to claim 1, wherein the communication between the transmitting station and the receiving station is time-divided to perform wireless communication, and the line is configured by a time slot, and is used. Time slots and the N time slots
A radio communication method comprising: setting an interval of each slot to about one half of a maximum Doppler frequency; and performing time diversity reception at a receiving station using the time slot and the N time slots. . 8. In a wireless communication method between a receiving station and a transmitting station that controls transmission power between the receiving station and the receiving station, when it is determined that a preset transmitting output has been reached, the receiving station sets N The number of antennas (N is a natural number of 1 or more) is set, and the interval between the already used receiving station antenna and each of the N antennas is set to about の of the wavelength of the carrier frequency. A wireless communication method comprising: performing spatial diversity reception at a receiving station using the N antennas. 9. A wireless communication method between a transmitting station performing transmission output control with the receiving station and the receiving station, wherein the number of the receiving stations is N when the code error rate is lower than a predetermined value. N is a natural number greater than or equal to 1), and the interval between the antenna of the receiving station already used and each of the N antennas is set to about 1/2 of the wavelength of the frequency frequency. A wireless communication method comprising: performing spatial diversity reception at a receiving station using a plurality of antennas. 10. The wireless communication method according to claim 1, wherein N (N is a natural number of 1 or more) different antennas set at a receiving station at a distance near half the wavelength of the carrier frequency. A wireless communication method, wherein spatial diversity reception is also performed. 11. The wireless communication method according to claim 1, wherein quadrature amplitude modulation is used as a modulation method. 12. The wireless communication method according to claim 1, wherein a phase shift keying is used for a modulation method. 13. The wireless communication method according to claim 1, wherein a frequency shift keying is used as a modulation method. 14. The wireless communication method according to claim 1, wherein coded modulation is used as a modulation method. 15. The wireless communication method according to claim 1, wherein the modulation method is 16-level quadrature amplitude modulation, and when a preset condition is reached, 2-branch reception to 4-branch reception is performed. Characteristic wireless communication method. 16. The wireless communication method according to claim 15, wherein two-branch reception is two-space diversity reception, and four-branch reception is two-space diversity reception and two-frequency diversity reception.