JPH09284859A - Hybrid radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To utilize effectively advantages of both basic frequency band communication and spread spectrum communication while minimizing the increase in the circuit scale and the control amounts by adopting both the basic frequency band communication and spread spectrum communication and selecting the same information transmission rate for the both to use selectively the basic frequency band communication and spread spectrum communication. SOLUTION: When a communication opposite party is retrieved, either of basic frequency band communication means or a spread spectrum communication means is optionally selected or a signal of the basic frequency band communication and a signal of the spread spectrum communication are sent/received alternately. When the signal of the basic frequency band communication comes from the opposite party or the opposite party gives an instruction of the implementation of the basic frequency band communication, a spread spectrum communication radio equipment 20 is stopped and a basic frequency band communication radio equipment 10 is selected. In the opposite case to above, the spread spectrum communication radio equipment 20 is selected and the basic frequency band communication radio equipment 10 is stopped. Thus, the system makes communication with the opposite party selectively by using the radio equipment of each system while minimizing the increase in the circuit scale and the control amounts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid wireless communication system for performing communication by selectively using baseband communication and spread spectrum communication.

[0002]

2. Description of the Related Art Radio communication such as mobile communication or personal communication includes basic band communication and spread spectrum communication.
In the basic band communication, a wireless carrier wave is modulated by an information bit string to be transmitted, and frequency-multiplexed or time-division multiplexed and transmitted. This has the advantage that the device configuration is simple.

In spread spectrum communication, an information bit string to be transmitted is spread-modulated by a known high-speed code string, and a high-speed signal string obtained is secondarily modulated to transmit a radio carrier, or the information bit string is used to modulate a radio carrier. After that, it is spread-modulated as a secondary modulation with a known high-speed code sequence and transmitted. This is resistant to interference and allows the use of the same frequency between cells. In addition, suppression of multipath delayed waves by spreading gain or multipath combining by RAKE (rake) reception (path diversity)
Is also possible, and there is an advantage that non-instantaneous handoff using the RAKE function is possible.

[0004]

Basic band communication is vulnerable to interference and requires an interference detection function and a frequency (or time slot) allocation control function for repeatedly using frequencies used in cell units or for avoiding interference. It was Further, when the delay amount of multipath becomes relatively large with respect to the information bit rate, the signal transmission quality is deteriorated due to intersymbol interference, so that an equalizer is required.

The spread spectrum communication requires a spread modulation circuit, a complicated despread synchronization circuit, and a transmission power control circuit, which causes a problem that the device configuration becomes complicated. In addition, these circuits require high-speed operation, which requires large power consumption. On the other hand, when a system using basic band communication and a system using spread spectrum communication are installed independently, a dual mode terminal (slave station) that selectively uses corresponding communication means according to each service area ). However, both conventional systems are different systems having different basic information bands, modulation systems, control systems, frame configurations, etc., and the terminal has to be equipped with dual communication means corresponding to both systems.

The present invention is a hybrid radio communication system which selectively uses base band communication and spread spectrum communication and can effectively utilize the advantages of both while minimizing the increase in circuit scale and control amount. Radio equipment for base band communication that has already been used (base station / slave station)
It is an object of the present invention to provide a hybrid wireless communication system that allows the introduction of a wireless device for spread spectrum communication anew while continuing to use the wireless communication system.

[0007]

The hybrid wireless communication system of the present invention includes both baseband communication and spread spectrum communication, and sets the information rates of both to be the same. As a result, the bandwidths on both wireless lines differ depending on whether or not there is spread, but the primary modulation method, control method, frame configuration,
The information source coding method and the like can be commonly set.

Further, the wireless device having the basic band communication means and the spread spectrum communication means selects either one of the communication means at the time of searching for a communication partner, or selects the signal of the basic band communication and the spread spectrum communication. Alternately receive or transmit signals, and if the other side has received a signal for basic band communication or instructed to perform basic band communication, stop the spread spectrum communication means and select the basic band communication means, In the opposite case, the base band communication means is stopped and the spread spectrum communication means is selected. As a result, it is possible to selectively communicate with the wireless device of each system while suppressing an increase in circuits and controls to the minimum.

Further, a radio apparatus having either one of the basic band communication means or the spread spectrum communication means can always communicate within the hybrid radio communication system of the present invention using only the communication means. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a first embodiment of the present invention (claim 1). In the description of the present embodiment, a case will be described where the basic band communication is the TDMA-TDD system such as PHS and the spread spectrum communication is the same TDMA-TDD type frame configuration, primary modulation system, and control system as PHS. Further, in the configuration of the wireless device shown in FIG. 1, for simplification, the transmission / reception changeover switch, the demultiplexing and synchronization control circuit, the encoding / decoding circuit, the control circuit, etc. are omitted, and the primary band communication and the spread spectrum communication primary Only the functions related to the secondary modulation unit and its demodulation unit are shown.

In the figure, a baseband communication radio apparatus 10 is shown.
Is a modulator 11, a carrier wave generator 12, a transmitter (T) 1
3, transmitting / receiving antenna 14, receiver (R) 15, demodulator 1
6. It has a carrier wave regenerator 17. With this configuration, it is possible to modulate the carrier wave with the transmission information bit string and transmit the modulated signal, and demodulate the received signal with the reproduced carrier wave to obtain the received information bit string.

The spread spectrum communication radio apparatus 20 includes modulators 21-1 and 21-2, a spread code string generator 22, a carrier wave generator 23, a transmitter (T) 24, and a transmitting / receiving antenna 2.
5, receiver (R) 26, demodulators 27-1 and 27-2, carrier wave regenerator 28, and despread code string generator 29. With this configuration, the transmission information bit string is spread-modulated with a higher-speed known code string, the carrier is secondarily modulated with the obtained high-speed signal string, transmitted, the received signal is demodulated with the regenerated carrier, and the despread code string is further The received information bit string can be obtained by performing the despreading process at. The order of the spreading process and the modulation may be reversed, the carrier wave may be modulated by the information bit string, and then spread modulation may be performed as the secondary modulation by a known high-speed code string before transmission. Further, the order of demodulation and despreading processing may be similarly reversed.

The shared radio apparatus 30 includes modulators 31-1 and 3-3.
1-2, spreading code sequence generator 32, carrier wave generator 33, transmitter (T) 34, transmission / reception antenna 35, receiver (R) 3
6, demodulators 37-1, 37-2, carrier wave regenerator 38, despreading code sequence generator 39, and switch 40. In this configuration, when the switch 40 is turned off, it becomes the same as the baseband communication wireless device 10, and the switches 40-1 and 40
When -2 is turned on, it becomes the same as the spread spectrum communication radio apparatus 20, and the function of the basic band communication and the spread spectrum communication can be switched by turning the switch on and off.

Here, the band on the wireless line for the basic band communication and the spread spectrum communication differs depending on the presence / absence of spreading as shown in a and b, but the primary modulation system, the control system, the frame structure, and the information source code. The conversion method and the like may be completely common, or some of them may be changed according to each method. For example, as an information source coding method, AD is used for basic band communication.
LD-CE for spread spectrum communication using PCM method
A low bit rate method such as the LP method may be used together with the error correction method. In addition, as a layer 3 signal in the control signal, addition / change may be added as necessary in each method such as adding a transmission power control function for spread spectrum communication.

In the hybrid radio communication system as shown in FIG. 1, the base band communication radio apparatus 10 and the spread spectrum communication radio apparatus 20 communicate with the corresponding radio apparatus using only their respective communication means (FIG. During,). The shared wireless device 30 turns the switch 40 off or on at the time of searching for a communication partner, selects either one of the basic band communication and the spread spectrum communication, and starts communication by transmitting or waiting for reception. Yes (in the figure,).

Further, the shared radio apparatus 30 transmits / receives a control signal by either baseband communication or spread spectrum communication, and whether a control signal by baseband communication has arrived from the other party of communication or baseband communication by the control signal. , The spread spectrum communication means is stopped (switch 4
0 is turned off) to start the basic band communication, and in the opposite case, the basic band communication means is stopped (the switch 40 is turned on) to start the spread spectrum communication (,, in the figure).

Further, the shared radio apparatus 30 transmits and receives a control signal by either baseband communication or spread spectrum communication, recognizes the communication means of the communication apparatus by the control signal from the other party of communication, and thereafter, A communication means used for communication is selected, and the information is instructed using a control signal to start communication (in the figure,). Further, when the shared wireless device 30 alternately receives the control signals for the baseband communication and the spread spectrum communication, and whether the control signal for the baseband communication has arrived from the other party of communication or has instructed the baseband communication by the control signal. Stops the spread spectrum communication means (turns off the switch 40) to start the basic band communication, and in the opposite case stops the base band communication means (turns on the switch 40) to start the spread spectrum communication (in the figure, ,).

Further, the shared radio apparatus 30 alternately receives the control signals for the basic band communication and the spread spectrum communication, recognizes the communication means of the communication apparatus according to the control signal from the communication partner side, and performs the subsequent communication. The communication means to be used is selected, and the information is instructed using a control signal to start communication (in the figure,). (Second Embodiment) FIG. 2 shows a second embodiment of the present invention (claim 2).

In this embodiment, each of the wireless devices shown in FIG. 1 is applied to a base station and a slave station. Base band communication base station 10A having only base band communication means as a base station
And a base station 20A for spread spectrum communication having only spread spectrum communication means. As a slave station, a slave station for base band communication 10B having only base band communication means,
A spread spectrum communication slave station 20B having only spread spectrum communication means and a shared slave station 30B having both communication means and selectively used are arranged.

The base band communication slave station 10B or the spread spectrum communication slave station 20B communicates with the corresponding base band communication base station 10A or spread spectrum communication base station 20A by using only the respective communication means ( In the figure,
). The shared slave station 30B turns the switch 40 off or on at the time of searching for a base station to be a communication partner, selects either one of the basic band communication or the spread spectrum communication means, and transmits the transmission signal of the corresponding base station. Communication is started by waiting for and receiving (in the figure).

The shared slave station 30B includes a base station 10A for base band communication and a base station 20A for spread spectrum communication.
The control signal transmitted from the base station is alternately received, and when the control signal by the base band communication arrives from the base station side, the spread spectrum communication means is stopped (switch 40 is turned off) to start the base band communication, and vice versa. In this case, the basic band communication means is stopped (switch 40 is turned on) and spread spectrum communication is started (in the figure).

FIG. 3 shows a cell configuration example to which the second embodiment is applied. In the figure, a cell with a small cell radius (microcell) is used for basic band communication, and a cell with a large cell radius (macrocell) is used for spread spectrum communication. Here, 51 is a base band communication cell formed by the base band communication base station 10A, and 52 is a spread spectrum communication cell formed by the spread spectrum communication base station (SS) 20A. With such a configuration, in a micro cell having a large number of cells, it is possible to simplify the base station and reduce the power consumption of the slave station. Further, in a macro cell that has a relatively small number of cells, requires a large transmission power, and has a large multipath delay, it is possible to improve resistance to interference by spread spectrum communication.

In the example shown in FIG. 3, macro cells are arranged so as to include micro cells. In this case, the spread spectrum communication signal has a low power density, the interference to the other party is small, and even if the base band communication signal becomes an interference, the influence can be reduced by the spreading gain.
However, in order to minimize the interference between the basic band communication and the spread spectrum communication, the basic band communication frequency and the spread spectrum communication frequency may be separated as shown in FIG. In FIG. 4, the horizontal axis represents time and the vertical axis represents frequency. 61 is a control signal for base band communication, 62 is a base band communication signal (down), 63 is a base band communication signal (up), 6
4 is a control signal for spread spectrum communication, 65-1, 65-
2 is a spread spectrum communication signal (downlink), 66-1, 66
-2 is a spread spectrum communication signal (uplink).

On the other hand, as shown in FIG. 5, a micro cell (cell for basic band communication 51) and a macro cell (cell for spread spectrum communication 52) may be arranged separately. In this case, mutual interference can be suppressed even if the basic band communication frequency and the spread spectrum communication frequency are shared as shown in FIG. The notation in FIG. 6 is the same as that in FIG. (Third Embodiment) FIG. 7 shows a third embodiment of the present invention (claim 3).

Here, the configuration of the shared base station 30A having the basic band communication means and the spread spectrum communication means will be described. A baseband signal processing circuit and a control circuit 41 are added to the shared wireless device 30 shown in FIG. 1, and a switch 40 is turned on / off by a selection signal generated therein. Reference numeral 42 is a network interface for connecting to a network.

The shared base station 30A alternately receives the control signals transmitted from the base station communication slave station 10B and the spread spectrum communication slave station 20B, and recognizes the communication means of the slave station by the control signal. Select the corresponding communication means and start communication. In this case, as shown in FIG. 8, the control signal 71 is the base band communication, and the communication signal (TCH)
Can select basic band communication or spread spectrum communication according to the communication means of the partner station or the state of the wireless line. That is, TCH downlink 1, TCH downlink 3, TCH uplink 1, TCH uplink 3 are spread spectrum communication, and TCH
Downlink 2 and TCH uplink 2 can be baseband communications.

[0027]

As described above, in the hybrid wireless communication system of the present invention, for example, in an area such as an urban area where the cell radius is small and the delay amount of multipath is small, the base station for base band communication (or shared base station) is used. It is possible to reduce the power consumption of the slave station by using the basic band communication means) and the basic band communication means of the shared slave station.

On the other hand, in areas such as suburbs where the traffic is relatively small, it is effective to increase the transmission power to increase the cell size. However, this increases interference between cells and reduces the delay amount of multipath. There is a growing problem. In such an area, by using a base station for spread spectrum communication (or spread spectrum communication means for shared base station) and spread spectrum communication means for shared slave station, it is possible to improve interference resistance and improve deterioration due to multipath delayed waves. You can

Also, a slave station having only one of the communication means of either the base band communication or the spread spectrum communication can be used in the hybrid wireless communication system of the present invention. Further, according to the present invention, base band communication and spread spectrum communication can be selectively used according to the application and local conditions, and the advantages of both can be effectively utilized in one system.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a cell configuration example to which the second embodiment is applied.

FIG. 4 is a time chart of a transmission signal corresponding to the cell configuration example of FIG.
The figure which shows an example of frequency allocation.

FIG. 5 is a diagram showing another cell configuration example to which the second embodiment is applied.

6 is a time chart of transmission signals corresponding to the cell configuration example of FIG.
The figure which shows an example of frequency allocation.

FIG. 7 is a diagram showing a third embodiment (configuration of a shared base station 30A) of the present invention.

8 is a diagram showing an example of time / frequency allocation of transmission signals corresponding to the embodiment of FIG.

[Explanation of symbols]

 10 base band communication wireless device 10A base band communication base station 10B base band communication slave station 11,21,31 modulator 12,23,33 carrier wave generator 13,24,34 transmitter 14,25,35 transmit / receive antenna 15, 26, 36 Receiver 16, 27, 37 Demodulator 17, 28, 38 Carrier regenerator 20 Spread spectrum communication radio device 20A Spread spectrum communication base station 20B Spread spectrum communication slave station 22, 32 Spread code string generation 29, 39 Despreading code sequence generator 30 Shared radio equipment 30A Shared base station 30B Shared slave station 40 Switch 41 Baseband signal processing circuit and control circuit 42 Network interface 51 Basic band communication cell 52 Spread spectrum communication cell 61 Basic Control signal for band communication 62 Base band communication signal (downlink) 3 baseband communication signal (up) 64 spread spectrum communication control signal 65 spread spectrum communication signals (downlink) 66 spread spectrum communication signals (uplink) 71 Control signal

Claims (3)

[Claims] 1. A radio apparatus having a basic band communication unit for modulating a carrier wave with an information bit string to be transmitted and transmitting the carrier wave, and demodulating a received signal with a reproduced carrier wave to obtain an information bit string, and an information bit string in the basic band communication unit. The information bit string at the same speed is spread-modulated with a known high-speed code string, the carrier wave is secondarily modulated with the obtained high-speed signal string, or the carrier wave is modulated with the information bit string and then the known high-speed code string is used. A radio apparatus having spread spectrum communication means for performing spread modulation and transmission, and despreading and demodulating a received signal to obtain an information bit string, and a radio apparatus having the base band communication means and the spread spectrum communication means are provided. In a hybrid wireless communication system, a wireless device having the base band communication means and the spread spectrum communication means is a communication device. At the time of searching for the other party, either the base band communication or the spread spectrum communication is selected, and the transmission signal of the wireless device having only the corresponding communication device or the wireless device transmitting by the corresponding communication device is selected. A first communication starting means for starting communication upon reception and a communication means of either basic band communication or spread spectrum communication are selected, and a radio device having only corresponding communication means or a corresponding communication means waits Second communication starting means for starting communication by transmitting the control signal to the wireless device being operated, and communication instructed by the received control signal by transmitting and receiving a control signal by either base band communication or spread spectrum communication. A third communication starting means for starting communication using the means, and control by either base band communication or spread spectrum communication A fourth method of transmitting and receiving a signal, recognizing a communication means included in the communication device by the received control signal, selecting a communication means to be used for the subsequent communication, instructing the information using the control signal, and starting communication Communication is started using communication means, which alternately receives the control signals for baseband communication and spread spectrum communication, and which is recognized from the received control signal, or by the communication means designated by the received control signal. And a control signal for baseband communication and spread spectrum communication are alternately received, the communication means included in the communication device is recognized by the received control signal, and the communication means used for the subsequent communication is selected. And at least one communication starting means of the sixth communication starting means for instructing the information by using a control signal to start the communication, and one of the communication starting means. Hybrid wireless communication system, characterized in that is configured to initiate communication with a start means. 2. A base station and a slave station having baseband communication means for modulating a carrier wave with an information bit string to be transmitted and transmitting it, and demodulating a received signal with a reproduced carrier wave to obtain an information bit string, and the baseband communication means. An information bit string having the same speed as the information bit string is spread-modulated with a known high-speed code string, the carrier wave is secondarily modulated with the obtained high-speed signal string, or the carrier wave is modulated with the information bit string, and then a high-speed known A base station and a slave station having spread spectrum communication means for spread-modulating with a code string and transmitting, and despreading and demodulating a received signal to obtain an information bit string, and the base band communication means and the spread spectrum communication means In a hybrid wireless communication system including a shared slave station, the shared slave station is a baseband communication or a spread spectrum communication. A first communication starting means for starting communication by selecting one of the communication means and receiving a transmission signal of a base station having only the corresponding communication means, and a control signal for baseband communication and spread spectrum communication. It is characterized in that the communication is started by using one of the communication starting means of the second communication starting means, which alternately receives and starts the communication by using the communication means recognized from the received control signal. Hybrid wireless communication system. 3. The hybrid wireless communication system according to claim 2, further comprising a shared base station having a base band communication unit and a spread spectrum communication unit, wherein the shared base station is either base band communication or spread spectrum communication. First communication starting means for starting communication by selecting and transmitting / receiving one communication means, and control signals for baseband communication and spread spectrum communication are alternately received, and communication held by the slave station according to the received control signal. A second means for recognizing the means, selecting a communication means to be used for the subsequent communication, instructing the information using a control signal, and starting communication.
2. A hybrid wireless communication system, characterized in that the communication is started by using one of the communication starting means.