JPH02276320A - Communication equipment - Google Patents

Abstract

PURPOSE:To switch a radio channel without interrupting communication and also, providing a specific time slot by providing a local oscillator controllable an oscillation frequency independently at each receiver, and receiving another radio channel simultaneously when switching the radio channel. CONSTITUTION:When both the quality of the output signals of the receivers 1 and 2 inputted from terminals 16 and 17, respectively do not satisfy a reference value at a quality judging circuit 14, a control part 12 interrupts reception by a space diversity reception system transiently, and the receiver in which the quality of the output signal becomes worse, for example, the receiver 2 switches the oscillation frequency of its own local oscillator, and switches the radio channel. The quality judging circuit 14 judges the quality of the output signal of the receiver 2 inputted via an output terminal 8 and the terminal 16, and when the securing of the quality is confirmed, a control signal is sent out to a selection circuit 22 via an input terminal 22 so as to select the output signal of the receiver 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is based on FDPilIA (Frequency D
The present invention relates to a communication device having a feature of wireless channel switching in a mobile communication system based on multiple access.

(Conventional technology) Conventionally, F
DMA mobile communication devices share one local oscillator between two receivers (for example, OKI
Technical Review J53 [127 (1987-7) P, 20). PSK (Phasa 5hift Keying)
When transmitting digital signals using a modulation method such as modulation, when switching the radio channel used between an opposing mobile station and an opposing mobile station based on instructions from the base station, the base station first switches to the mobile station. Based on instructions from the base station, the mobile station switches the frequency of its receiver's local oscillator and waits, and the base station switches the transmission frequency to the radio channel to improve the line quality. The wireless channel was inspected, and if it was found to be in good condition, the wireless channel would be used for future communications.

In addition, in a communication device using the FDMA digital mobile communication system, in addition to the information time slot, a specific time slot is provided for inspecting the quality of the line to be switched.
During this specific time slot, the receiver's local oscillator (synthesizer) was switched at high speed to receive a specific radio channel, and the switching was performed after determining whether switching was possible (for example, "electronic"). Information and Communication Engineers Technical Research Report” 88 [293] (1988-11-22) P
, 81-86).

(Problem to be solved by the invention) However, in the communication device having the above configuration that adopts the space diversity reception method, all receivers share one local oscillator, so only signals of one frequency can be received at the same time. Therefore, when a request to switch wireless channels occurs during information communication, there is a problem that communication is temporarily interrupted until the switching is completed.

Furthermore, in the communication device provided with the specific time slot, 1
You can switch wireless channels without interrupting communication! ! (Since a specific time slot is provided, the transmission speed of the transmission line increases by the amount of this time slot, which results in a problem that the required frequency band is wide and the efficiency of frequency use decreases.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a communication device that can switch wireless channels without interrupting communication or providing a specific time slot. shall be.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a local oscillator that can independently control the oscillation frequency in an FDMA type communication device having a plurality of receivers that perform spectrum diversity reception. are provided in each of the receivers, so that when switching radio channels, other radio channels are simultaneously received.

(Operation) When switching radio channels during reception using the sparse diversity reception method, one receiver of the space diversity receiver continues to receive the current radio channel, and the other receiver The system controls its local oscillator to receive the radio channel to be switched, inspects the quality of the radio channel, and switches the radio channel by taking steps such as paralleling the sending ends.

(Example) FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, receivers 1 and 2 normally operate as space diversity receivers. That is, antenna 3,
4 is placed at a position where the correlation between received signal levels is small, and the received signals are input to receivers 1 and 2 through input terminals 4 and 7, respectively. The local oscillators (not shown) of the receivers 1 and 20 can each independently control their oscillation frequencies, and in this case, they oscillate carrier waves of the same frequency. Therefore, the receivers 1, 2 receive the same radio channel and output the same output signal through the output terminal 5.8. Output signals from the output terminals 5 and 8 are input to the selection circuit 21, respectively, and are also input to the quality determination circuit 14 through terminals 16 and 17. The quality determination circuit 14 compares the quality of the input signals and outputs the results to the control unit 12 through terminals 15.13. Control unit 12
Based on the above results, a control signal is applied to the input terminal 22 of the selection circuit 2 through the terminal 20, and the one with the better quality is selected from the output signals of the receivers 1 and 2, and is output from the terminal 9 to the outside. Output.

As explained above, reception is normally performed using the space diversity reception method, but when the quality of the output signals of receivers 1 and 2 deteriorates and no longer meet the standard value, the radio channel in use is switched to another radio channel. You need to switch to a wireless channel. Therefore, switching of wireless channels will be explained below.

When the quality of the output signals of the receivers 1 and 2 inputted through the terminals 1'6 and 17, respectively, no longer satisfy the reference value, the quality determination circuit 14 notifies the control unit 12 of this fact through the terminals 15 and 13. . The control unit 12 temporarily suspends reception using the space diversity reception method, and sends the receiver whose output signal quality is worse, for example, receiver 2, to another free wireless channel where the quality can be ensured. Terminal 19. A control signal is sent through the control terminal 10. The receiver 2 switches to the radio channel by switching the oscillation frequency of its own local oscillator based on the control signal. Quality judgment circuit 14
is output terminal 8. The quality of the output signal of the receiver 2 input through the terminal 16 is determined. When the control unit 12 confirms that the quality of the output signal of the receiver 2 is ensured through the determination, it instructs the selection circuit 21 to select the output signal of the receiver 2 at the terminal 20. A control signal is sent through the input terminal 22, and the terminal 18. Control terminal 11
Sends control signals through. The receiver 1 switches to the wireless channel by switching the oscillation frequency of its own local oscillator based on the control signal. Thereafter, reception begins according to the normal space diversity reception method and the radio channel switching operation is completed.

As described above, according to this embodiment, since the sending end can be configured in parallel, it is possible to switch wireless channels without interrupting information communication.

(Effects of the Invention) As described above in detail, according to the present invention, FDMA
In this type of communication equipment, by configuring the local oscillator of each receiver that performs space diversity reception to be independently controllable, when switching wireless channels,
One receiver can receive the current wireless channel as it is, the other receiver can inspect the quality of the wireless channel to be switched, and the line can be switched by taking steps such as paralleling the sending ends. Therefore, wireless channels can be switched without interrupting communication. In addition, since there is no need to provide a specific time slot in the transmission signal for checking the line quality of another wireless channel when switching wireless channels, it is possible to prevent the transmission speed on the transmission path from increasing. It is possible to improve frequency usage efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the invention. 1.2...Receiver, 3,6...Antenna, 4,7゜22...Input terminal, 5,8...Output terminal, 9,13
゜15.16-20...Terminal, 10.11...Control terminal, 12...Control unit, 14...Quality determination circuit, 2
1...Selection circuit.

Claims (1)

[Claims] In an FDMA communication device having a plurality of receivers that perform space diversity reception, each of the receivers is provided with a local oscillator that can independently control the oscillation frequency, so that other radio channels can be simultaneously received when switching radio channels. A communication device characterized by: