JPH0936788A - Time diversity communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the transmission efficiency by allowing a transmission section and a reception section to keep a common sequence operational amplifier and revising information arrangement sequence synchronously for each transmission repetitively according to a sequence pattern so as to reduce an average error rate. SOLUTION: A transmission section 18 and a reception section 19 respectively keep common sequence patterns and a sequence revision circuit 23 and a sequence arrangement circuit 10 revise synchronously the arrangement sequence of information for each transmission repetitively according to the sequence pattern. When a time diversity reception control circuit 17 requests repetitive transmission to a transmission section 18 when the reception section 19 cannot decode reception information. The circuit 23 divides the transmission information and inserts transmission information to by channel location of a time slot of plural channels and revises the inserted position repetitively synchronously according to the sequence pattern. The circuit 10 extracts the reception information included in the time slot received according to the sequence pattern.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for time division multiplex communication. Particularly, it is suitable for use in mobile communication. The present invention relates to a technique for improving error rate characteristics and transmission efficiency of time diversity communication.

[0002]

2. Description of the Related Art As one form of a mobile communication system, the transmission timing from a mobile station to a base station and the transmission timing from a base station to a mobile station are divided into upstream and downstream time slots, and these upstream and downstream time slots are respectively classified. It is known that communication is performed by alternately transmitting and receiving the time slots of. This conventional example will be described with reference to FIGS. FIG. 5 is an overall configuration diagram of the mobile communication system. FIG.
FIG. 3 is a configuration diagram of signals used for communication. FIG. 7 is a block diagram of a conventional time diversity communication device. FIG.
FIG. 4 is a time chart showing the operation of the conventional time diversity communication device.

For communication between the base station 21 and the mobile station 22 shown in FIG. 5, as shown in FIG. 6, one framed signal is divided into two slots, and f1 and f2 are independent of each other.
Is a press talk communication in which a carrier frequency is modulated and signals are alternately transmitted and received at different slot timings. This type of communication is generally a multi-carrier T
Called DMA (Time Division Multiple Access), N
There are a number of channels (frequency), and by using all of them as appropriate, frequencies used by base stations and mobile stations in the area are sequentially assigned. That is, control is performed such that allocation is performed if there is a space, and waiting is performed if there is no space. Therefore,
Depending on the channel usage, the same frequency may be assigned to multiple time slots (f1 = f
2) In some cases, a different frequency is assigned to each time slot (f1 ≠ f2).

Here, a signal from the mobile station 22 to the base station 21 is an upstream signal, and a signal from the base station 21 to the mobile station 22 is a downstream signal. FIG. 6 shows the case of Nch channel multiplexing, and the first to Nchth frame configurations are the same. Here, description is made assuming that one framed signal (128 bits) is divided into two slots (68 bits), but the number of divisions is not fixed.

As shown in FIG. 7, the base station 21 and the mobile station 22 each include a transmission section 18 and a reception section 19 for performing press talk communication, and the transmission section 18 has a predetermined cycle T.
The receiving unit 19 includes a transmission signal generation circuit 1, an error detection coding circuit 2, a transmission signal buffer 3, a frame division circuit 4 and a transmitter 5 as means for repeatedly transmitting the same information signal over a plurality of M times. Is a receiver 8, a decoding circuit 9, and an error detection circuit 1 as means for performing time diversity reception processing on the information signals received a plurality of times M times.
6, a phase shift circuit 12, an envelope level measuring circuit 13, a weighting circuit 14, and a received signal buffer 15.

The transmission signal generation unit 24 stores a transmission signal generation circuit 1 for generating information to be transmitted, an error detection coding circuit 2 for adding an error detection code, and a transmitted signal until the reception confirmation is received from the partner station. Transmit signal buffer 3 and frame division circuit 4 for dividing information into a plurality of slots
Consists of

The diversity combining section 25 is an analog-to-digital converter 11 for converting a received wave, which is an analog quantity, into a digital quantity, and a phase shift circuit 12 for adjusting the phase of a reception signal affected by fading to a reference phase of its own station. , An envelope level measuring circuit 13 for measuring the reception level, and a weighting circuit 14 for weighting in proportion to the reception level.

In this conventional example, the transmission unit 18 adjusts the number of transmissions M depending on whether the reception confirmation signal from the transmission unit 18 of the other party, which is the destination of the signal to be transmitted, can be confirmed or not received. The time diversity transmission control circuit 6 is provided as a means for doing so. In addition, the receiving unit 19
When the same information is received a plurality of times, if there are errors in all the times, the signals are matched with the reference phase of the receiving unit 19, and weighted by a weighting coefficient proportional to the envelope level to synthesize. A time diversity reception control circuit 17 is provided as a means for doing so.

Next, the operation of the conventional example will be described. Base station 2
Since there is no difference in the basic configuration between 1 and the mobile station 22,
The mobile station 22 will be described as a transmitting side, and the base station 21 will be described as a receiving side. The configuration of the conventional example is roughly divided into a transmission unit 18 and a reception unit 19, both of which are connected to a transmitting / receiving antenna 20 via a high frequency switch 7. In the transmission unit 18, the output of the time diversity transmission control circuit 6 is connected to the transmission signal generation circuit 1 and the transmission signal buffer 3, and an information signal is generated in the transmission signal generation circuit 1 by the conventional time diversity control and an error occurs. Error detection bits are added by the detection coding circuit 2 and accumulated in the transmission signal buffer 3.

In the receiving section 19, the transmitting / receiving antenna 20 is used.
Is connected to a receiver 8 via a high-frequency switch 7, the received signal output from the receiver 8 is sent to a decoding circuit 9, and the diversity combining IF signal is sent to an analog-digital converter 1.
After being converted into a digital signal by 1, the signal is input to the phase shift circuit 12 and the envelope level measuring circuit 13, combined with the contents of the reception signal buffer 15 and newly stored in the reception signal buffer 15. The information signal and the error detection bit output from the decoding circuit 9 are input to the error detection circuit 16 and inspected for a code transmission error. The time diversity reception control circuit 17 controls the reception signal buffer 15 based on the output of the error detection circuit 16 to obtain a reception signal sequence.

Next, the transmission control method will be specifically described.
For the sake of explanation, the maximum value of the number M of time diversity branches is “3”. First, the mobile station 22 assumed to be the transmitting side
Generates an information signal for one frame by the transmission signal generation circuit 1, adds an error detection bit by the error detection coding circuit 2, and stores the information signal in the transmission signal buffer 3 and by the frame division circuit 4 into two frames. It is divided and modulated by the modulator in the transmitter 5, and two slot times T1U (1), T
Send to 1U (2). Two slot times T1D
In the downlink signal reception period of (1) and T1D (2), the receiver 8
The received signal is demodulated at to receive the reception confirmation signal from the base station 21, which is the partner station. At the same time, time diversity control is performed on the received signal, and details of the control of the received signal will be described later.

Secondly, if the reception confirmation signal received at the time T2U immediately before the time T2U, that is, at the time T1D is non-reception (a code transmission error occurs), the number of time diversity branches is increased. . That is, the information signal stored in the transmission signal buffer 3 and transmitted at time T1U and added with the error detection bit is again modulated by the modulator in the transmitter 5 and transmitted in two slots. On the other hand, when the reception confirmation signal is confirmation (code transmission without error), without performing transmission control of time diversity,
The transmission signal generation circuit 1 generates a new transmission signal, the error detection coding circuit 2 adds an error detection bit and writes it in the transmission buffer 3, and the frame division circuit 4 divides it into two frames for transmission. It is modulated by the modulator in the machine 5 and transmitted in two slots. Also, at time T3U, the same processing as the transmission control of time diversity performed at time T2U is performed according to the reception confirmation signal received at time T2D of the immediately preceding reception period. In the time chart of FIG. 8, since the reception confirmation signal received at time T1D and time T2D is non-reception, the information signal is repeatedly transmitted three times.

Even when the reception confirmation signal from the base station 21, which is the other station, is not received and the number of time diversity branches is increased, the number of time diversity branches for the information signal is a predetermined value M (here, " 3 "), a new information signal is generated by the transmission signal generation circuit 1 without increasing the number of time diversity branches, and the error detection coding circuit 2 adds an error detection bit to the transmission signal buffer. In addition to writing the data in 3, the frame is divided into two frames by the frame division circuit 4, modulated by the modulator in the transmitter 5, and transmitted in two slots.

Next, the reception control of the conventional time diversity will be described. In the base station 21, the uplink signal from the mobile station 22 is received by the transmitting / receiving antenna 20 at time T1U, and is input to the receiver 8 via the high frequency switch 7. In the receiver 8, the received signal is demodulated and input to the decoding circuit 9 to be received data. The received data is input to the error detection circuit 16, inspects whether a code transmission error has occurred, and transmits the inspection result to the mobile station 22 as a reception confirmation signal at time T1D. When no code transmission error is detected, the received data is output as a received signal sequence as it is, but when a code transmission error is detected, the receiver 8
The IF signal for time diversity combining from
After being converted into a digital value by the digital converter 11, it is input to the phase shift circuit 12 and the envelope level measuring circuit 13 to match the phase of the fading wave component with the reference phase of the receiving section 19 and also the envelope level measuring circuit. 1
After being weighted by the weighting circuit 14 with a weighting coefficient proportional to the output of No. 3, it is written in the reception signal buffer 15. As described above, the case where an error is detected at time T1U is described here.

At time T2U as well as at time T1U, the error detection circuit 16 performs error detection on the received signal output from the decoding circuit 9 and the time diversity combining IF.
The signal is converted into a digital value by the analog / digital converter 11 and input to the phase shift circuit 12 and the envelope level measuring circuit 13, and the phase of the fading wave component is received by the receiving section 19
Of the weighting circuit 14 with a weighting coefficient proportional to the output of the envelope level measuring circuit 13
And the signal received at time T1U stored in the received signal buffer are combined and written into the received signal buffer 15 again. If the error detection result of the received signal output from the decoding circuit 9 indicates no error, the reception confirmation is transmitted as a reception confirmation signal and the signal is output as a reception signal sequence. However, here, since a code transmission error has occurred again, after decoding the signal stored in the reception signal buffer 15 as a reception signal, the error detection circuit 16 checks the presence or absence of a code transmission error. If no error is detected as a result of the inspection, reception confirmation is transmitted as a reception confirmation signal, and the signal stored in the reception signal buffer 15 is output as a reception signal sequence. However, in the present invention, since an error is detected, non-reception is transmitted as a reception confirmation signal and the reception of the information signal is waited for again.

At time T3U, the same time diversity reception processing as at time T2U is performed. Here, an error is also detected in the combined signal, but since the number of time diversity branches has reached the default value “3”, the received signal buffer 1
The signal within 5 is output as a received signal sequence. Since new information is transmitted at time T4U, the same reception processing as that performed at time T1U is performed.

As described above, the reception confirmation signal indicating whether or not the signal is transmitted without error is used to efficiently perform the time diversity to improve the transmission characteristic of the mobile communication channel.

[0018]

However, since the diversity branches are constructed in terms of time, when the mobile station is stationary or is moving very slowly, the correlation between the diversity branches becomes very large. However, sufficient improvement in characteristics cannot be obtained.

That is, in the example of FIG. 8, the same information signal is transmitted and received at regular intervals. However, when fading and other occurrence cycles are synchronized with this cycle, the same information signal is obtained every time. A situation occurs in which a signal cannot be received. Alternatively, if fading or the like has a characteristic that depends on the carrier frequency, a situation occurs in which an information signal with the same carrier frequency cannot be received every time.

The present invention has been made against such a background, and an object thereof is to provide a time diversity communication apparatus capable of increasing the diversity effect. An object of the present invention is to provide a time diversity communication device capable of reducing the average error rate. An object of the present invention is to provide a time diversity communication device capable of improving transmission efficiency.

[0021]

SUMMARY OF THE INVENTION The present invention focuses on a time division multiplex communication system in which a frame is divided into a plurality of slots and modulated with independent carrier frequencies, and a plurality of slots are provided for each branch of time diversity. The most main feature is to combine the frequency diversity effect obtained by changing the order and prevent the deterioration of time diversity due to the high time correlation, that is, the correlation between diversity branches. This is different from the conventional technique in that the order of a plurality of slots into which a frame is divided is changed for each time diversity bundle.

That is, the first aspect of the present invention is to provide a time diversity provided with a transmission section for repeatedly transmitting the same information a plurality of times and a reception section for decoding one information from a signal repeatedly received a plurality of times. It is a communication device.

Here, a feature of the present invention is that the transmitting unit and the receiving unit hold a common sequence pattern, and the sequence sequence of information is synchronized for each repeated transmission according to the sequence pattern. There is a means to change it.

The transmitting unit and the receiving unit are configured as a two-way communication device respectively including them, and are configured to include means for repeatedly requesting the transmission source from the transmission source when the reception information cannot be decoded by the receiving unit. be able to.
Thereby, for example, it can be configured as a base station and a mobile station of the mobile communication system.

The means for synchronously changing the transmission information divides the transmission information and inserts the respective transmission information into any channel position of a time slot having a plurality of channels, and this insertion position is repeatedly transmitted according to the sequence pattern for each transmission. It is desirable to include means for synchronously changing. further,
It is preferable that the means for synchronously changing includes means for extracting reception information included in the time slots received according to the order pattern.

A second aspect of the present invention is a multi-carrier TDMA communication system provided with the time diversity communication device.

A third aspect of the present invention is a mobile communication system of a multi-carrier TDMA communication system provided with a small number of base station devices and a large number of mobile station devices communicating with the base station devices.

A fourth aspect of the present invention is a mobile station device for this mobile communication system.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of an apparatus according to the present invention.

The present invention is a time diversity communication apparatus provided with a transmitter 18 for repeatedly transmitting the same information a plurality of times and a receiver 19 for decoding one information from a signal repeatedly received a plurality of times.

Here, the feature of the present invention is that the transmitting unit 18 and the receiving unit 19 hold a common sequence pattern, and the sequence sequence of information is synchronized for each repeated transmission according to the sequence pattern. The order changing circuit 23 and the order aligning circuit 10 are provided as means for changing the order.

The time diversity reception control circuit 17 is a two-way communication device having a transmission section 18 and a reception section 19, respectively, and as a means for repeatedly requesting the transmission source from the transmission source when the reception information cannot be decoded by the reception section 19. I have it.

The sequence changing circuit 23 divides the transmission information, inserts the respective transmission information into any channel position of the time slot having a plurality of channels, and synchronously repeats this insertion position according to the sequence pattern for each transmission. change.

The order arrangement circuit 10 includes means for extracting the reception information included in the time slot received according to the order pattern.

The present invention is implemented as a multi-carrier TDMA communication system equipped with a time diversity communication device. Mobile communication using this multi-carrier TDMA communication system includes a small number of base station devices and a large number of mobile station devices that communicate with the base station devices.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a time chart showing the operation of the embodiment of the present invention. Between the base station 21 and the mobile station 22, the information signal is framed for each predetermined block, and the frame (1
Communication is performed using a mobile communication system that uses a time division multiplexing system in which 28 bits are divided into a plurality of slots (64 bits) for transmission and reception. Here, the carrier frequencies of the plurality of slots are independent of each other. The overall configuration of this mobile communication system is shown in FIG.
checking ...

The present invention includes a base station 21 and the base station 21.
And a mobile station 22 connected by a radio line. The mobile station 22 and the base station 21 alternately transmit and receive radio signals divided into a plurality of slots in one frame at a predetermined cycle T to communicate information signals. The transmitting section 18 and the receiving section 19 are respectively provided, and the transmitting section 18 is a means for repeatedly modulating the same information signal over a plurality of M times of the period T, and the transmitting signal generating circuit 1 and the error detection coding circuit 2 are provided. , A transmission signal buffer 3, a frame division circuit 4, an order change circuit 23, and a transmitter 5, and the reception unit 19 includes a receiver 8 as a means for performing time diversity reception processing on the reception information of a plurality of M times, and a decoding circuit. 9, an error detection circuit 16, a phase shift circuit 12, an envelope level measurement circuit 13, a weighting circuit 14, a received signal buffer 15, and an order alignment circuit 10. It is between diversity apparatus.

Here, the feature of the present invention is that the previous signal stored in the transmission signal generator 24 instead of the new transmission signal when the reception confirmation from the partner station is not obtained at the time of signal transmission. For the same information as the transmitted signal, the order of the slots is changed by the order changing circuit 23 and the maximum M (M
Is an integer). Further, when the signal is received, the output of the decoding circuit 9 or the output of the diversity synthesizing unit 25 is rearranged in the order-arrangement circuit 10 according to a predetermined rule by the order-change circuit 23 when the signal is transmitted, according to a predetermined order. It is in.

Next, the operation of the embodiment of the present invention will be described. In the embodiment of the present invention, there is no difference in implementation method between the base station 21 and the mobile station 22, but in describing the embodiment of the present invention, the mobile station 22 will be described as the transmitting side and the base station 21 will be described as the receiving side. The configuration of the present invention is roughly divided into a transmitting unit 18 and a receiving unit 19, both of which are connected to a transmitting / receiving antenna 20 via a high frequency switch 7. The output of the time diversity transmission control circuit 6 of the transmission unit 18 is connected to the transmission signal generation circuit 1, the transmission signal buffer 3 and the frame division circuit 4, and the information signal is transmitted by the time diversity control of the present invention. The error detection coding circuit 2 adds an error detection bit, and the error signal is stored in the transmission signal buffer 3. The signal accumulated in the transmission signal buffer 3 is divided into a plurality of slots by the frame division circuit 4, the order of the frames is changed by the order change circuit 23 according to a predetermined rule, and the transmitter 5 independently makes the changes. It is transmitted after being modulated with a different carrier frequency.

In the receiving section 19, the transmitting / receiving antenna 20 is used.
Is connected to a receiver 8 via a high-frequency switch 7, the received signal output from the receiver 8 is sent to a decoding circuit 9, and the diversity combining IF signal is sent to an analog-digital converter 1.
After being converted to a digital signal by 1, the signal is input to the phase shift circuit 12 and the envelope level measuring circuit 13, and thereafter,
The signals of a plurality of slots are arranged in one frame by the order arrangement circuit 10, combined with the contents of the reception signal buffer 15, and newly stored in the reception signal buffer 15.
The information signal and the error detection bit output from the decoding circuit 9 are input to the error detection circuit 16 and inspected for a code transmission error. The time diversity reception control circuit 17
The received signal buffer 15 based on the output of the error detection circuit 16
To obtain a received signal train.

Next, the transmission control method will be specifically described.
For the sake of explanation, it is assumed that the maximum value of the number M of time diversity branches is "3" and one frame is divided into two slots for communication. FIG. 2 is a time chart showing the flow of time.

First, the mobile station 22, which is assumed to be the transmitting side,
The transmission signal generation circuit 1 generates an information signal for one frame, the error detection coding circuit 2 adds an error detection bit, and the accumulated signal is stored in the transmission signal buffer 3 and divided into two slots by the frame division circuit 4. Then, the order change circuit 23 determines the order of the slots, the first slot is modulated with the carrier frequency f1 and the second slot is modulated with the carrier frequency f2 in the transmitter 5, and the times T1U (1) and T1U (1),
Send to 1U (2). At this time, the carrier frequencies f1 and f
Independent of 2. During the downlink signal reception period at times T1D (1) and T1D (2), the receiver 8 demodulates the received signal and receives the reception confirmation signal from the base station 21, which is the partner station.
At the same time, time diversity control is performed on the received signal, and details of the control of the received signal will be described later.

Secondly, when the reception confirmation signal received at time T2U immediately before time T2U, that is, at time T1D is non-reception (a code transmission error occurs), the number of time diversity branches is increased. . In other words, the information signal stored in the transmission signal buffer 3 and transmitted at time T1U, to which the error detection bit is added, is again divided into two slots by the frame division circuit 4, and the order change circuit 23 makes the first change this time. The positions of the slot and the second slot are exchanged, and the first slot has the carrier frequency f2 at time T2D (2),
The second slot is modulated by the transmitter 5 at the carrier frequency f1 at time T2D (1) and transmitted. On the other hand, when the reception confirmation signal is reception confirmation (code transmission without error), a new transmission signal is generated by the transmission signal generation circuit 1 without performing transmission control of time diversity, and the error detection code is generated. The error detection bit is added by the digitization circuit 2 and written in the transmission buffer 3, and divided into two slots by the frame division circuit 4, and the order of the slots is determined by the order change circuit 23. The first slot is the carrier frequency f1. Then, the second slot is modulated by the transmitter 5 with the carrier frequency f2 and transmitted at times T2U (1) and T2U (2), respectively. Also, at time T3U, the same processing as the transmission control of time diversity performed at time T2U is performed according to the reception confirmation signal received at time T2D of the immediately preceding reception period.

In the time chart of FIG. 2, time T1D,
Since the reception confirmation signal received at time T2D is non-reception, the information signal is repeatedly transmitted three times.

Even when the reception confirmation signal from the base station 21, which is the partner station, is not received and the number of time diversity branches is increased, the number of time diversity branches for the information signal is a predetermined value M (embodiment). Then, when 3) is exceeded, a new information signal is generated by the transmission signal generation circuit 1 without increasing the number of time diversity branches, and an error detection bit is added by the error detection encoding circuit 2 to add a transmission signal buffer. Write to 3 and frame division circuit 4
Are divided into two slots by the order change circuit 23, and the order of the slots is determined by the order change circuit 23. The first slot is the carrier frequency f1.
Then, the second slot is modulated by the transmitter 5 with the carrier frequency f2 and transmitted at times T4U (1) and T4U (2), respectively.

Next, the time diversity reception control of the present invention will be described. At the base station 21, time T1U
In (1) and T1U (2), the upstream signal from the mobile station 21 is received by the transmitting / receiving antenna 20, and is input to the receiver 8 via the high frequency switch 7. The receiver 8 has a time T1U.
The received signal modulated by the carrier frequency f1 is demodulated in (1) and the received signal modulated by the carrier frequency f2 is demodulated at time T1U (2), and is input to the decoding circuit 9 to be received data. Although the order of the received data is arranged by the order arrangement circuit 10, the order of the slots is not changed at time T1U. Therefore, the received data is directly input to the error detection circuit 16 to inspect whether a code transmission error has occurred or not. The result is time T1
D is transmitted to the mobile station 22 as a reception confirmation signal. If no code transmission error is detected, the received data is output as it is as a received signal sequence, but if a code transmission error is detected, the time diversity combining IF signal from the receiver 8 is an analog signal. After being converted into a digital quantity by the digital converter 11, it is input to the phase shift circuit 12 and the envelope level measurement circuit 13, and the phase of the fading wave component is adjusted to the reference phase of the receiving unit 19, and
After weighting is performed by the weighting circuit 14 with a weighting coefficient proportional to the output of the envelope level measuring circuit 13, the order is arranged by the order changing circuit 10. However, at time T1U, the order of the slots is not changed, so that the received signal is used as it is. It is written in the buffer 15. As described above, the embodiment of the present invention describes the case where an error is detected at time T1U.

At time T2U as well as at time T1U, the order of the received signal output from the decoding circuit 9 is changed by the order changing circuit 10 by replacing the information of the first receiving slot with the information of the second receiving slot.
Error detection is performed by the error detection circuit 16 in one frame, and the IF signal for time diversity combination is converted into a digital amount by the analog-digital converter 11 and input to the phase shift circuit 12 and the envelope level measurement circuit 13. ,
The phase of the fading wave component is matched with the reference phase of the receiving unit 19, and after weighting by the weighting circuit 14 with a weighting coefficient proportional to the output of the envelope level measuring circuit 13, the order changing circuit 10 gives information on the first receiving slot. The information of the second reception slot is exchanged, and the received signal which is made into one frame and the signal received at the time T1U stored in the received signal buffer 15 are combined and written in the received signal buffer 15 again. If the error detection result of the received signal output from the decoding circuit 9 indicates no error, the reception confirmation is transmitted as a reception confirmation signal and the signal is output as a reception signal sequence. However, in the embodiment of the present invention, since a code transmission error has occurred again, after the signal stored in the reception signal buffer 15 is decoded as a reception signal, the error detection circuit 16 inspects for the presence of a code transmission error. If no error is detected as a result of the inspection, reception confirmation is transmitted as a reception confirmation signal, and the signal stored in the reception signal buffer 15 is output as a reception signal sequence. In the embodiment of the present invention, since an error is detected even at this stage, non-reception is transmitted as a reception confirmation signal and the reception of the information is waited for again.

At time T3U, the same time diversity reception processing as at time T2U is performed. In the embodiment of the present invention, an error is also detected in the combined signal, but since the number of time diversity branches has reached the default value of 3, the signal in the reception signal buffer 15 is output as a reception signal sequence. Time T4
In U, new information is transmitted, so the same reception process as that performed at time T1U is performed.

As described above, the number of time diversity branches is determined according to the reception confirmation signal indicating whether or not the signal is transmitted without error, and the order of slots is changed to reduce the correlation between diversity branches. By doing so, it is possible to improve the transmission characteristics of the mobile communication transmission path while reducing the decrease in transmission efficiency.

As described above, the time diversity method of the present invention is a method in which the number of diversity branches can be increased or decreased by a reception confirmation signal indicating whether or not a signal has been transmitted without error, so that the transmission efficiency is reduced by the time diversity. There is an advantage that can be reduced. In addition, since the correlation between diversity branches is reduced by changing the slot order, the effect is more remarkable than in the conventional example.
3 and 4 show graphs of average error rate characteristics and transmission efficiency showing the effect of the present invention. Figure 3 shows the average CNR (Carrier N
It is a figure which shows the relationship between oise Rasio) and an average error rate. The horizontal axis shows the average CNR [dB], and the vertical axis shows the average error rate. FIG. 4 is a diagram showing the relationship between the average CNR and the transmission efficiency. The horizontal axis represents average CNR [dB] and the vertical axis represents transmission efficiency. As shown in FIG. 3, the present invention has a large error reduction effect as compared with the conventional example. Moreover, as shown in FIG. 4, the transmission efficiency can be improved.

[0051]

As described above, according to the present invention,
The diversity effect can be increased. This makes it possible to reduce the average error rate and improve the transmission efficiency.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between average CNR and average error rate.

FIG. 4 is a diagram showing a relationship between average CNR and transmission efficiency.

FIG. 5 is an overall configuration diagram of a mobile communication system.

FIG. 6 is a configuration diagram of signals used for communication.

FIG. 7 is a block configuration diagram of a conventional time diversity communication device.

FIG. 8 is a time chart showing the operation of a conventional time diversity communication device.

[Explanation of symbols]

 1 Transmission Signal Generation Circuit 2 Error Detection Coding Circuit 3 Transmission Signal Buffer 4 Frame Division Circuit 5 Transmitter 6 Time Diversity Transmission Control Circuit 7 High Frequency Switch 8 Receiver 9 Decoding Circuit 10 Sequence Alignment Circuit 11 Analog-to-Digital Converter 12 Transfer Phase circuit 13 Envelope level measuring circuit 14 Weighting circuit 15 Received signal buffer 16 Error detection circuit 17 Time diversity reception control circuit 18 Transmitter 19 Receiver 20 Antenna 21 Base station 22 Mobile station 23 Sequence changing circuit 24 Transmit signal generator 25 Diversity combiner

Claims (7)

[Claims] 1. A time diversity communication apparatus comprising: a transmitter that repeatedly transmits the same information a plurality of times; and a receiver that decodes one information from a signal repeatedly received a plurality of times. The time diversity communication device, wherein the receiving unit holds a common order pattern, and has means for synchronously changing the arrangement order of information for each repeated transmission according to the order pattern. 2. A two-way communication device having each of the transmission unit and the reception unit, further comprising means for requesting a transmission source to repeatedly transmit when reception information cannot be decoded by the reception unit. Time Diversity Communication Equipment. 3. The means for synchronously changing the transmission information, inserting the transmission information into any channel position of a time slot having a plurality of channels, and repeatedly transmitting the insertion position according to the order pattern. 3. The time diversity communication device according to claim 1, further comprising means for synchronously changing each time. 4. The time diversity communication apparatus according to claim 1, wherein the means for synchronously changing includes means for extracting reception information included in a time slot received according to the order pattern. . 5. A multi-carrier TDM equipped with the time diversity communication device according to claim 1. Description:
A communication method. 6. The mobile communication system according to claim 5, comprising a small number of base station devices and a large number of mobile station devices communicating with the base station devices. 7. A mobile station apparatus for the mobile communication system according to claim 6.