JP3758326B2 - Code division multiple access mobile phone device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile phone device that communicates with a plurality of base stations using a code division multiple access method, and more particularly, to a mobile phone device that communicates while switching base stations with movement.
[0002]
[Prior art]
There are several methods for multiple access in a mobile phone device.
[0003]
In the conventional frequency division multiple access method, time division multiple access method, or a combination thereof, when changing the base station as the mobile phone device moves, the communication frequency is changed. Is interrupted.
[0004]
Therefore, a code division multiple access scheme has been devised. In this case, since the multiplexing is performed by the spreading code at the same frequency, the base station can be switched basically in the same frequency channel. However, even in the code division multiple access method, in order to switch to a base station that operates on a different frequency channel, it is necessary to connect by switching the frequency. In this case, there is a disadvantage that the conversation is interrupted during the call as in the conventional case.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, it is an object of the cellular phone device of the call be switched base station interrupted difficult CDMA system to mobile phone devices communicate It is to provide .
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a mobile phone device that communicates by a code division multiple access method, wherein the mobile phone device includes a plurality of receiving systems that receive signals from a base station, and a base station. One transmission system for transmitting a signal, and the plurality of reception systems receive a first antenna for receiving a signal from a base station on a first frequency channel, and a signal received by the first antenna. A first receiving system comprising a first low-noise amplifier for amplifying; a second antenna for receiving a signal from a base station on a second frequency channel different from the first frequency channel; A second reception system comprising a second low noise amplifier for amplifying a signal received by two antennas, wherein the transmission system comprises a third low noise amplifier for amplifying a signal to be transmitted to a base station, A third low noise amplifier? Consists to the second antenna for transmitting the signal output to the base station, and wherein the switching the frequency channel used for transmission during the burst transmission stop.
In addition, the mobile phone device communicates by a code division multiple access method, a first antenna that receives a signal from a base station through a first frequency channel, and a first antenna that amplifies the signal received by the first antenna. One low noise amplifier and a signal from the base station are received by a second frequency channel different from the first frequency channel, and the signal is transmitted by switching the frequency channel while burst transmission is stopped to the base station. A second antenna, a second low-noise amplifier that amplifies a signal received by the second antenna, a signal output from the first low-noise amplifier, and an output from the second low-noise amplifier A synthesizer that synthesizes signals, a demodulator that demodulates the signal output from the synthesizer, a receiver that converts the signal output from the demodulator into speech, and a transmitter that converts speech into a signal; Above A modulator for modulating a signal output from the story unit, characterized in that it and a third low-noise amplifier for amplifying a signal output from the modulator.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0013]
FIG. 1 is a configuration diagram of a code division multiple access mobile phone device according to a first embodiment of the present invention.
[0014]
First, in the reception system, a radio communication signal transmitted from a base station (not shown) is input to the duplexer 3 via the antenna 1. Here, the reception frequency (all channels) band is limited, and the signal is guided to the low noise amplifier 11. The signal amplified by the low noise amplifier 11 is converted to an intermediate frequency by the frequency mixer 12. The received intermediate frequency signal is signal band limited by the band pass filter 13, amplified to a required level by the variable gain amplifier 14, and demodulated by the demodulator 15. The demodulated baseband signal is decoded by the baseband signal processing circuit 6. Here, the decoded and output signals include a digital control signal and a digital call signal. Among these signals, the digital control signal is supplied to the control circuit 5 and identified. On the other hand, the digital call signal is returned from the handset 8 after being returned to the analog call signal.
[0015]
On the other hand, in the transmission system, the transmission voice is converted into a transmission signal by the transmitter 7 and then converted into a digital transmission signal by the baseband signal processing circuit 6. The digital transmission signal is encoded by the baseband signal processing circuit 6 together with the digital control signal generated by the control circuit 5, and then input to the modulator 31 and modulated into a quadrature modulation signal. The modulated signal is adjusted by the variable gain amplifier 32 so as to have an output level required from the base station, and is converted into a high frequency signal of a predetermined frequency channel by the frequency mixer 33. Then, unnecessary spurious signals are removed by the band pass filter 34, amplified to a required output level by the power amplifier 35, and then transmitted from the antenna 1 to the base station via the duplexer 3.
[0016]
In the local oscillation system, the variable frequency oscillator 51 and the variable frequency oscillator 61 controlled by the control circuit 5 transmit two different frequencies. The local oscillation signal is amplified by the buffer amplifier 52 and the buffer amplifier 62 so that the frequency does not change due to the influence of the oscillator on the load variation, and then the signal synthesizer 57 synthesizes the signals of two frequencies. Is done. Since the synthesized signals of the two frequencies need to be supplied to the frequency mixer 12 of the reception system and the frequency mixer 33 of the transmission system at the same time, they are distributed by the signal distributor 56.
[0017]
Further, the control circuit 5 includes a microcomputer as a main control unit, and the variable gain amplifier 14 is configured so that the frequency settings of the variable frequency oscillator 51 and the variable frequency oscillator 61 and the input level of the demodulator 15 are appropriate. In addition to adjusting the gain and adjusting the gain of the variable gain amplifier 32 so that the transmission output level is appropriate, it has a function of controlling each part.
[0018]
Next, frequency conversion will be described in an embodiment of the present invention. FIG. 2 is a diagram showing a frequency conversion method in the embodiment of the present invention.
[0019]
In FIG. 2, the frequencies of frequency channel A and frequency channel B that communicate with the base station are fa and fb, respectively, and the intermediate frequency of the mobile phone device is fi. In this case, there are two communication channels, but it is assumed that the modulation signals in the two frequency channels are the same. That is, instead of transmitting different information on the two channels, the two channels are used for path diversity.
[0020]
In the case of the reception operation, the frequency channel A signal 71 is converted into an intermediate frequency stage frequency channel A signal 81 by the oscillation frequency fLa of the variable frequency oscillator 51. Similarly, the signal 72 of the frequency channel B is converted into the signal 82 of the frequency channel B at the intermediate frequency stage by the oscillation frequency fLb of the variable frequency oscillator 61. In either case, it is converted to the intermediate frequency fi. At this time, unnecessary sidebands are generated, which can be removed by the bandpass filter 13.
[0021]
In this way, it is possible to convert the signals of the two frequency channels into the same intermediate frequency.
[0022]
In a code division multiple access system mobile phone device, a plurality of reception paths can be received simultaneously by the rake receiving means, so that signals of two frequency channels are demodulated and combined even if converted to the same intermediate frequency. Can do.
[0023]
Further, in the case of the transmission operation, the same operation is just the reverse of the reception operation. That is, the same modulated signal can be transmitted simultaneously to two frequency channels.
[0024]
In this way, path diversity can be realized even in a situation where the frequency channel is switched, so that a handoff operation for switching the frequency channel can be performed without interruption of the call.
[0025]
As another embodiment, a configuration diagram of a code division multiple access mobile phone device in the second embodiment of the present invention shown in FIG. 3 will be described.
[0026]
In the second embodiment, the reception system, the transmission system, and the local oscillation system of the apparatus are each provided with two independent systems. Thus, since it is not necessary to synthesize two local oscillation frequencies, the influence of distortion in the frequency mixer 12, the frequency mixer 22, and the frequency mixer 33 and the frequency mixer 43 can be reduced, which is effective in reducing spurious.
[0027]
FIG. 4 is a block diagram of a code division multiple access mobile phone apparatus according to the third embodiment of the present invention.
[0028]
The third embodiment is a modification of the second embodiment and has a configuration in which the intermediate frequency stages of the reception system and the transmission system are shared. As a result, the cost can be reduced with the same performance as the apparatus shown in the second embodiment.
[0029]
FIG. 5 is a block diagram of a code division multiple access mobile phone apparatus according to the fourth embodiment of the present invention.
[0030]
In the fourth embodiment, the circuit is reduced as much as possible while placing importance on performance. The most different point from the above-described embodiment is that the transmission system is one system.
[0031]
In this case, the following devices are required for switching the frequency channel at the time of transmission.
[0032]
That is, in the uplink, which is transmission from the mobile phone device to the base station, transmission is generally performed in bursts in order to reduce traffic and power consumption of the mobile phone device. For example, in the US IS-95 standard, since one frame is 20 milliseconds and there are 16 power control groups in one frame, the minimum unit of power control is 1.25 milliseconds. Therefore, there is a minimum transmission stop time of 1.25 milliseconds in burst transmission. On the other hand, the variable frequency oscillator 51 is usually constituted by a PLL, and with the current technology, it is possible to sufficiently reduce the frequency switching time to about 1 millisecond.
[0033]
Therefore, the frequency channel is switched using the transmission stop time during burst transmission.
[0034]
Regarding reception, the configuration is the same as that of the third embodiment, but the sub-antenna 2 is provided for the low-noise amplifier 21 in order to improve reception sensitivity. By taking the distance between the antenna 1 and the sub-antenna 2 as much as necessary, the effect of space diversity can also be obtained.
[0035]
In the above four embodiments, the mobile station apparatus of the CDMA automobile mobile phone system has been described. However, the present invention is not necessarily limited to this method, and can be considered to achieve the object of the present invention. Other configurations are also included. Furthermore, the configuration, circuit, means, and the like of the device described in the embodiments are not limited to those shown in the embodiments. Specifically, in the embodiment, the case of two frequency channels has been described. However, the number of frequency channels is not limited to two, but includes configurations that can be similarly considered for two or more frequency channels.
As described above, according to an embodiment of the present invention, when switching the base station to the mobile telephone device according to the movement of the user to communicate, even when switching the frequency channel, so that the conversation during a call is not interrupted Can be. Further, the reception sensitivity can be improved by providing a plurality of antennas and reception systems. Further, by providing a plurality of transmission / reception systems, a system that is not used in normal operation can be used for backup, and reliability is improved.
[0036]
【The invention's effect】
According to the present invention, it is possible to provide a mobile telephone device of the call be switched base station interrupted difficult CDMA system to mobile telephone device communicates.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a code division multiple access mobile phone device according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a frequency conversion method according to an embodiment of the present invention.
FIG. 3 is a configuration diagram of a code division multiple access mobile phone device according to a second embodiment of the present invention.
FIG. 4 is a configuration diagram of a code division multiple access cellular phone device according to a third embodiment of the present invention.
FIG. 5 is a configuration diagram of a code division multiple access mobile phone device according to a fourth embodiment of the present invention.
[Explanation of symbols]
1 ... antenna, 2 ... sub-antenna, 3 ... duplexer,
5 ... Control circuit, 6 ... Baseband signal processing circuit,
7 ... speaker, 8 ... receiver,
11 ... Low noise amplifier,
12 ... frequency mixer (reception system),
13: Band pass filter (receiving system),
14: Variable gain amplifier (receiving system),
15 ... demodulator,
16: Signal distributor (reception system),
17 ... Signal synthesizer (reception system),
21 ... Low noise amplifier (reception system) (system 2),
22 ... frequency mixer (reception system) (system 2),
23: Band pass filter (receiving system) (system 2),
24 ... Variable gain amplifier (receiving system) (system 2),
25 ... demodulator (system 2),
31. Modulator,
32 ... Variable gain amplifier (transmission system),
33 ... Frequency mixer (transmission system),
34 ... band pass filter (transmission system),
35 ... Power amplifier,
36: Signal distributor (transmission system),
37 ... Signal synthesizer (transmission system),
41 ... modulator (system 2),
42 ... variable gain amplifier (transmission system) (system 2),
43 ... frequency mixer (transmission system) (system 2),
44 ... band pass filter (transmission system) (system 2),
45 ... Power amplifier (system 2),
51: Variable frequency oscillator,
52. Buffer amplifier,
56 ... Signal distributor,
57 ... Signal synthesizer,
61: Variable frequency oscillator (system 2),
62: Buffer amplifier (system 2),
66 ... signal distributor (system 2),
71 ... frequency channel A signal,
72 ... frequency channel B signal,
81 ... Signal of frequency channel A in the intermediate frequency stage,
82: Frequency channel B signal in the intermediate frequency stage.

Claims (5)

A mobile phone device that communicates by a code division multiple access method,
A plurality of reception systems for receiving signals from the base station, and one transmission system for transmitting signals to the base station,
The plurality of receiving systems include a first antenna that receives a signal from a base station on a first frequency channel, and a first low-noise amplifier that amplifies the signal received by the first antenna. And a second antenna that receives a signal from a base station on a second frequency channel different from the first frequency channel, and a second that amplifies the signal received on the second antenna. A second receiving system comprising a low noise amplifier;
The transmission system includes a third low-noise amplifier that amplifies a signal to be transmitted to a base station, and the second antenna that transmits a signal output from the third low-noise amplifier to the base station. A cellular phone device characterized by switching a frequency channel used for transmission while transmission is stopped. A mobile phone device that communicates by a code division multiple access method,
A first antenna for receiving a signal from the base station on a first frequency channel;
A first low noise amplifier for amplifying a signal received by the first antenna;
A second antenna for receiving a signal from a base station on a second frequency channel different from the first frequency channel, and transmitting a signal by switching the frequency channel while burst transmission is stopped to the base station;
A second low noise amplifier for amplifying a signal received by the second antenna;
A combiner that combines the signal output from the first low noise amplifier and the signal output from the second low noise amplifier;
A demodulator that demodulates the signal output from the combiner;
A receiver that converts the signal output from the demodulator into speech;
A microphone that converts voice into a signal;
A modulator for modulating the signal output from the transmitter;
And a third low-noise amplifier for amplifying the signal output from the modulator. The mobile phone device according to claim 1 or 2,
A cellular phone device comprising a plurality of local transmission systems. The mobile phone device according to claim 1 or 2,
The local transmission system includes a first frequency oscillator that oscillates at a first frequency, and a second frequency oscillator that oscillates at a second frequency different from the first frequency,
The signal received by the first antenna is frequency-converted using the first frequency oscillator, and the signal received by the second antenna is frequency-converted using the second frequency oscillator. A signal transmitted from the second antenna is frequency-converted using the second frequency transmitter.   The cellular phone device, wherein the first antenna and the second antenna receive signals transmitted from the same or a plurality of different base stations simultaneously at two or more frequencies.

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