JP2001103036A - Transmitter, receiver and base station device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmitter, a receiver and a base station device capable of performing communications of a frequency hopping system, without being affected by transistional time necessary for the frequency switching of a synthesizer. SOLUTION: This transmitter is provided with a plurality of modulating means, which modulate carrier waves whose frequencies are mutually different by a modulation signal and output the carrier waves, a switching means which successively selects the plurality of modulating means according to a hopping pattern and supplies a data signal as the modulation signal to the selected modulating means, and a transmitting means which transmits an output signal from the plurality of modulating means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a transmitter, a receiver, and a base station apparatus.

[0002]

2. Description of the Related Art In recent years, a frequency hopping communication system known as one of spread spectrum communication systems has been used in mobile communication.

FIG. 9 is a block diagram illustrating the configuration of a conventional transmitter for transmitting a data signal such as a voice signal by the frequency hopping communication method. As shown in the figure, this transmitter includes a primary modulation section 51 that performs narrow band modulation (primary modulation) such as PSK or FSK on a data signal to be transmitted, and an oscillation under the control of a hopping control section 52. Multiplication that performs spread modulation on the output signal of the primary modulation unit 51 by multiplying the output signal of the primary modulation unit 51 by the output signal of the synthesizer 53 and the output signal of the primary modulation unit 51 and the synthesizer 53 whose frequency can be sequentially switched at regular time intervals. Vessel 54
And a band-pass filter 55.

Here, as shown in FIG. 9, the synthesizer 53 includes a frequency divider 531 for dividing a signal (an output signal of a VCO 534 described later) inputted at a frequency division ratio designated by the hopping control unit 52. A phase comparator 533 that outputs a signal corresponding to the phase difference between the output signal of the frequency divider 531 and the output signal of the reference oscillator 532, and the oscillation frequency is controlled by the output signal of the phase comparator 533. This is a PLL circuit composed of a VCO (voltage controlled oscillator) 534. With such a configuration, according to a change in the frequency division ratio specified by the hopping control unit 52,
The oscillation frequency of the VCO 534 can be sequentially switched.

[0005]

By the way, the oscillation frequency of the synthesizer 53 is ideally shown in FIG.
It is desirable that the switching be performed immediately in response to an instruction from the hopping control unit 52 as shown in FIG. However, in the case of the configuration shown in FIG. 9, it takes a long time to switch the oscillation frequency of the synthesizer 53. More specifically, as shown in FIG. 10B, after an instruction to switch the oscillation frequency to f4 is given to the synthesizer 53 operating at the oscillation frequency f1, the oscillation frequency is completely changed to f4. A transition time T is required before switching. When the output signal of the primary modulation section 51 is subjected to spread modulation using the signal illustrated in FIG. 10B and transmitted, the receiving side of the signal corresponds to the transition time T of the received signal. However, there is a problem that it is not possible to demodulate the part that performs the processing. On the other hand, spread modulation is performed on the output signal of the primary modulation section 51 only during the period when the frequency of the output signal from the synthesizer 53 is constant, and the signal output during the transition time T is not used for spread modulation. Although it is conceivable to do so, there is a problem that the time required for communication becomes longer by the transition time T.

On the other hand, a receiver using the frequency hopping communication system switches the oscillation frequency of the synthesizer at fixed time intervals, and obtains a signal before the spread modulation by multiplying a received signal by an output signal from the synthesizer. Has become. That is, the demodulation process performed in the receiver is also affected by the transition time.

SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances described above, and a transmitter and a receiver capable of performing communication of a frequency hopping system without being affected by the transient time required for frequency switching of a synthesizer. And a base station device.

[0008]

According to a first aspect of the present invention, there is provided a transmitter, comprising: a plurality of modulating means for modulating and outputting carrier waves having different frequencies with a modulating signal; Switching means for sequentially selecting the plurality of modulating means in accordance with the following, supplying a data signal as the modulated signal to the selected modulating means, and transmitting means for transmitting output signals from the plurality of modulating means. It is characterized by. Here, the transmitter includes the switching unit for a plurality of channels, and each switching unit includes:
The plurality of modulating units may be sequentially selected according to any one of a plurality of hopping patterns that do not overlap with each other. In addition, the receiver according to claim 3 includes a demodulator configured to provide a demodulator for demodulating a data signal carried on a carrier wave of a specific frequency from a received signal for each of a plurality of different carrier wave frequencies; Selecting means for sequentially selecting the plurality of demodulators according to a pattern and outputting a data signal from the selected demodulator. Here, the receiver may include the selection unit for a plurality of channels, and each selection unit may sequentially select the plurality of demodulators according to any of a plurality of hopping patterns that do not overlap with each other. . Further, the base station device according to claim 5 is a base station device including a transmitter and a receiver that perform communication with the mobile station device,
The transmitter modulates a carrier wave having a different frequency with a modulating signal, and sequentially selects the plurality of modulating means according to a hopping pattern, and modulates the data signal with respect to the selected modulating means. Switching means for supplying as a signal, and transmission means for transmitting output signals from the plurality of modulation means, wherein the receiver demodulates a data signal carried on a carrier wave of a specific frequency from a reception signal. A demodulating means provided for each of a plurality of different carrier frequencies, and a selecting means for sequentially selecting the plurality of demodulators according to a hopping pattern and outputting a data signal from the selected demodulator. And Here, the base station apparatus includes the switching unit and the selection unit for a plurality of channels, and the switching unit sequentially selects the plurality of modulation units according to any of a plurality of hopping patterns that do not overlap with each other. The selection means may sequentially select the demodulators according to any of the hopping patterns.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Such an embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the present invention.

A: First Embodiment FIG. 1 is a block diagram showing a configuration of a base station apparatus 1 using a transmitter according to the present invention. The base station device 1 is a device for performing wireless communication with a mobile station device located in a wireless zone formed by the base station device 1. Specifically, the base station apparatus 1 performs predetermined processing described later on each data signal supplied from the exchange 100 via any channel, and then transmits the data signal to the mobile station apparatus wirelessly. Send. In the present embodiment, a maximum of six channels (CH1 to CH
It is assumed that a data signal is supplied via 6).

As shown in FIG. 1, this base station apparatus 1
Switching units 111 to 116, switching control unit 12, modulation unit 131
To 13n and a transmission unit 14. In the following description, when it is not necessary to specify any one of the switching units 111 to 116 or any of the modulation units 131 to 13n, each switching unit and each modulation unit are referred to as “switching”. Unit 11 ”and“ Modulation unit 13 ”
Call.

The switching units 11 are provided in a number corresponding to the number of channels of the data signal transmitted from the exchange 100 (that is, six in the present embodiment), and each switching unit 11 has one input terminal. And n output terminals. Then, a data signal of a corresponding channel is input to an input terminal of each switching unit 11. On the other hand, n output terminals of each switching unit 11 are connected to each input terminal of n modulation units 12. In such a configuration, the switching unit 11
Under the control of the switching control unit 12, the switching operation of the switch is performed. Specifically, each switching unit 11 switches the switches under the control of the switching control unit 12 so that the supplied data signal is output to different modulation units 131 to 13n at fixed time intervals. FIG. 1 shows only the configuration of the switching unit 111 in order to prevent the drawing from being complicated.
Detailed configurations of the other switching units 112 to 116 are omitted.

The switching control unit 12 stores the same number of hopping patterns as the number of channels in an internal storage device, and controls the switching operation by each of the switching units 111 to 116 based on one of these hopping patterns. . Here, each of the plurality of hopping patterns is prepared corresponding to each channel, and switches the output destination of the data signal supplied to each switching unit 11 via each channel and the output destination of the data signal. It contains information for specifying timing and the like. In addition, each hopping pattern
An output signal from each switching unit 11 is connected to one of the modulation units 1
3 is set to be output only. That is,
The data signals output from the two or more switching units 11 are set so as not to be simultaneously supplied to any one of the modulation units 13 (so as not to overlap each other).

Each modulation section 13 is a destination to which the data signal is output from each switching section 11, and is provided with the same number or more than the number of channels. In the present embodiment, FIG.
It is assumed that n modulation units 131 to 13n are provided as shown in FIG. As shown in FIG. 2, each of these modulators 13 includes a primary modulator 13a, an oscillator 13b, a multiplier 1
3c, a bandpass filter 13d and an amplifier 13e.

The primary modulation section 13a performs narrow band modulation such as PSK or FSK on the data signals sequentially supplied from the switching section 11, and outputs the result. The oscillator 13b is connected to each modulation unit 1
3 outputs a carrier having a different frequency for each oscillator 13b. In the following, the frequencies of the carrier waves output from the oscillator 13b in the modulation units 131, 132,..., 13n are f1, f2,.

The multiplier 13c multiplies the output signal of the primary modulation section 13a by the carrier from the oscillator 13b to perform frequency conversion on the output signal of the primary modulation section 13a and outputs the result. Hereinafter, each of the modulation units 131 and 13
, 13n, the frequencies of the signals that have been frequency-converted by the multiplier 13c are F1, F2,. This signal is amplified by the amplifier 13e after passing through the bandpass filter 13d, and is output to the transmission unit 14.

Referring again to FIG. 1, transmitting section 14 combines the signals output from each modulating section 13 and transmits the combined signal to each mobile station apparatus via an antenna.

Next, a specific operation in this embodiment will be described. First, the switching control unit 12 controls a switching operation by the switching unit 11 based on a hopping pattern corresponding to a channel used for communication with the mobile station device. As a result, each switching unit 11 selects a different modulation unit 13 at regular time intervals, and provides the selected modulation unit 13
A data signal sequentially supplied from the exchange 100 via each channel is supplied.

That is, for example, when data signals 1 to 3 are supplied to switching units 111 to 113 via channels 1 to 3, respectively, as shown in FIG.
Outputs the data signal 1 supplied via the channel 1 to the modulation section 131 during times T0 to T1, and outputs
The signal is output to the modulation unit 135 during T2, and is output to the modulation unit 133 during time T2 to T3.
Data signal 2 supplied to switching section 112 and switching section 1
The same applies to the data signal 3 supplied to the data signal 13.

As described above, a part of the data signal of each channel is sequentially supplied from each switching unit 11 to each modulation unit 13. For example, in the example shown in FIG.
, A part of the data signal 1 is supplied from the switching unit 111 during the time T0 to T1, and the switching unit 1 is supplied during the time T3 to T4.
12, a part of the data signal 2 is supplied, and so on. The primary modulator 13a in the modulator 13 performs narrow band modulation such as PSK on the supplied data signal and sequentially outputs the data signal. The output signal from the primary modulator 13a is multiplied by the output signal from the oscillator 13b by the multiplier 13c, converted into a signal of a different frequency, and output. In other words, the carrier wave from the oscillator 13b is modulated by the output signal from the primary modulator 13a and output. After passing through the bandpass filter 13d, this signal is amplified by the amplifier 13e, and is combined with the signal output from the other modulation unit 13 in the transmission unit 14,
Output from the antenna.

Here, as shown in FIG.
When the signals 11 to 113 operate, as shown in FIG. 4, the data signal 1 is multiplied by the signal of the frequency f1 in the modulation unit 131 during the time T0 to T1 to be converted into a signal of the frequency F1. During T2, the signal is multiplied by the signal of frequency f5 in the modulation unit 135 and converted into a signal of frequency F5, and between time T2 and T3, the signal is multiplied by the signal of frequency f3 in the modulation unit 133 and converted into a signal of frequency F3. ,
.., Etc., are converted into signals having different frequencies at certain time intervals. The same applies to data signals 2 and 3. That is, according to the present embodiment, it is possible to obtain a signal similar to a signal obtained when spread modulation is performed by ideal frequency hopping shown in FIG.

As described above, according to the present embodiment, there is an advantage that communication can be performed without being affected by the transient time required for switching the oscillation frequency of the oscillator shown in the above-described conventional technique.

B: Second Embodiment Next, a configuration of a base station apparatus 2 using a receiver according to the present invention will be described with reference to FIG. The base station apparatus 2 is for performing wireless communication with a mobile station apparatus located in a wireless zone formed by the base station apparatus 2 in the same manner as the base station apparatus 1 described in the first embodiment. Device. Specifically, a radio signal transmitted from one or more mobile station devices is received and subjected to a predetermined process (described later), and the obtained data signals are exchanged by the exchange 100 via each corresponding channel. Send to

As shown in FIG. 5, this base station device 2
Receiving unit 21, demodulating units 221-222n, switching units 231-2
36 and a switching control unit 24. In the following description, when it is not necessary to specify any of the demodulation units 221 to 22n or any of the switching units 231 to 236, each demodulation unit and each switching unit are referred to as “demodulation”. Section 22 "and" switching section 23 "
Call.

The receiving section 21 has an antenna, receives a radio signal transmitted from one or more mobile stations by this antenna, and outputs it to each demodulation section 22. Here, the signal transmitted from each mobile station device is a signal to which spread modulation of the frequency hopping method has been applied. That is, it is a signal obtained by subjecting a data signal to be transmitted to primary modulation and then multiplying the data signal by a signal whose frequency switches at regular time intervals (see FIG. 7). In the following, similarly to the first embodiment, the frequency of the data signal is converted to F1 by multiplying the signal of the frequency f1, and the frequency of the data signal is converted to F2 by multiplying the signal of the frequency f2.
.., And the frequency of the data signal is converted to Fn by multiplying by the signal of frequency fn. Further, the frequency in an arbitrary section of the signal transmitted from each mobile station apparatus is different from the frequency in the corresponding section of the signal transmitted from another mobile station apparatus.

The demodulation units 22 are provided corresponding to the numbers of different frequencies included in the signal received from the mobile station device. In the present embodiment, since signals transmitted from each mobile station device include n types of frequencies F1 to Fn, n demodulation units 221 to 22n are provided. Here, each demodulation unit 22 corresponds to a “demodulator” in the claims. The term “demodulation means” in the claims is a general term for these demodulation units 22. As shown in FIG. 6, each demodulation unit 22 includes a bandpass filter 22a, an oscillator 22b, and a multiplier 22c.
And a detector 22d.

The center frequency and the bandwidth of the band-pass filter 22a are set so that only one of the frequency components F1-Fn received by the receiving unit 21 is passed. . Specifically, the bandpass filter 22a in the demodulation unit 221 has the frequency F
1 is passed, and the bandpass filter 2 in the demodulation unit 222 is
2a passes the signal of frequency F2,..., Demodulation unit 22n
The inner bandpass filter 22a passes a signal of the frequency Fn.

The multiplier 22c multiplies the signal output from the bandpass filter 22a by the output signal from the oscillator 22b and outputs the result. Here, the oscillator 2 in each demodulation unit 22
2b outputs signals of constant frequencies different from each other.
Specifically, by multiplying the output signal from the bandpass filter 22a by the signal from the oscillator 22b, the oscillation frequency of each oscillator 22b is returned so that the output signal of the bandpass filter 22a returns to the signal before spread modulation. Is set. That is, the oscillation frequency of the oscillator 22b in the demodulation unit 221 is set to f1, the oscillation frequency of the oscillator 22b in the demodulation unit 222 is set to f2,..., The oscillation frequency of the oscillator 22b in the demodulation unit 22n is set to fn. I have.

The detector 22d detects the output signal of the multiplier 22c by synchronous detection or asynchronous detection, and extracts and outputs a data signal.

The switching units 23 are provided in the same number as the number of channels (six in this embodiment).
3 has n input terminals and one output terminal. n
The input terminals are connected to each of the output terminals of the n demodulation units 22, while one output terminal outputs the data signal of the corresponding channel. The switching unit 23 selects one of the plurality of demodulation units 22 under the control of the switching control unit 24, and outputs a data signal from the selected demodulation unit via a corresponding channel (details will be described later). ). The switching control unit 24 has a plurality of hopping patterns corresponding to hopping patterns used when each mobile station performs frequency hopping spread modulation on a data signal, that is, a plurality of hopping patterns corresponding to each channel. The switching unit 23 is controlled based on the hopping pattern. Here, each hopping pattern is set so that two or more switching units 23 do not select any one of the demodulation units 22 at the same time (so as not to overlap each other). In other words, the data signal from each demodulation unit 22 is always output to only one switching unit 23.

Next, a specific operation of the present embodiment will be described. In the following, a description will be given of an example in which the base station device 2 receives signals subjected to frequency hopping spread modulation from three mobile station devices. First, the receiving unit 21
Receives the radio signal transmitted from each mobile station apparatus and outputs the radio signal to each demodulation unit 22. Signals transmitted from three mobile station devices are supplied to each demodulation unit 22, and each signal has a different frequency in each fixed section as illustrated in FIG. The bandpass filter 22a in each demodulation unit 22 includes:
Only one frequency component of this signal is passed. For example, the bandpass filter 22a in the demodulation unit 221 has the frequency F
Only one signal is passed. 7, the multiplier 22c in the demodulation unit 221 receives the time T
During the period from 0 to T1, the signal of channel 1 is supplied, and at time T3
During the period from to T4, the signal of channel 2 is supplied (see FIG. 8).

Next, the multiplier 22c is connected to the bandpass filter 22.
The output signal from a is multiplied by the signal from the oscillator 22b. The oscillation frequency of each oscillator 22b is f1,
, f2,..., the bandpass filter 22a
By multiplying the output signals (frequency F1, F2,...) By these signals, a signal before spread modulation can be obtained. For example, by multiplying the signal of the frequency F1 output from the bandpass filter 22a in the demodulation unit 221 by the signal of the frequency f1 output from the oscillator 22b, the signal output from the bandpass filter 22a is spread-modulated. The signal can be converted into a signal before (after primary modulation). The signal thus obtained is output from the detector 22d.
, And the resulting data signal is output to each switching unit 23. FIG. 8 is a diagram schematically illustrating a state of a signal output from each demodulation unit 22 to the switching unit 23 after performing the above-described processing on each signal illustrated in FIG. 7. Each data signal as shown in FIG. 8 is sequentially output to each switching unit 23.

Under the control of the switching control unit 24, each of the switching units 23 selects a data signal to be transmitted to a corresponding channel from the data signals output from each of the demodulation units 22, and outputs the selected data signal. I do. When the case of FIG. 8 is described as an example, the switching unit 231 corresponding to the channel 1 outputs
During T1, the output signal of the demodulation unit 221 is selected and output to the channel 1, and between time T1 and T2, the output signal of the demodulation unit 225 is output to the channel 1. Similar operations are performed for the other switching units 23. As a result, the signal transmitted from each mobile station device is transmitted to exchange 100 via the corresponding channel.

As described above, according to the present embodiment, similarly to the first embodiment, there is an advantage that communication can be performed without being affected by the transient time required for switching the oscillation frequency.

In the above description, the base station apparatus having the transmitter according to the present invention and the base station apparatus having the receiver according to the present invention have been described. And a receiver. That is, the data signal supplied from the exchange is subjected to the processing described in the first embodiment, and this signal is transmitted to the mobile station apparatus, while the hopping frequency spread modulation transmitted from the mobile station apparatus is applied to the data signal. The signal described above may be subjected to the processing described in the second embodiment, and the signal may be transmitted to the exchange.

The transmitter and the receiver according to the present invention can be applied not only to the base station apparatus but also to the mobile station apparatus. That is, while mounting the transmitter and the receiver according to the present invention on the mobile station device,
The data signal to be transmitted, such as a voice signal, is subjected to the processing described in the first embodiment, and this signal is transmitted to the base station device, while the frequency hopping spread modulation transmitted from the base station device is performed. The signal described above may be subjected to the processing described in the second embodiment, and this signal may be output as sound from a speaker.

In the first embodiment, the switching control unit 12 holds the same number of hopping patterns as the number of channels. However, the present invention is not limited to this, and the number of hopping patterns is larger than the number of channels. You may do so. In this case, each time communication with a mobile station apparatus using a certain channel is started, a hopping pattern used in the communication may be sequentially selected from the plurality of hopping patterns. On the other hand, also in the second embodiment, similarly, the switching control unit 24 holds a larger number of hopping patterns than the number of channels, and when starting communication with the mobile station apparatus, sequentially selects a hopping pattern to be used in the communication. You may make it.

[0038]

As described above, according to the present invention,
When performing spread modulation or despread on a data signal,
There is no need to switch the oscillation frequency of the oscillator. Therefore, there is an advantage that communication can be performed without being affected by the time required for switching the oscillation frequency of the oscillator.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a base station device using a transmitter according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of a modulation unit according to the first embodiment.

FIG. 3 is a diagram for explaining an operation of a switching unit in the embodiment.

FIG. 4 is a diagram for explaining a modulation operation in the embodiment.

FIG. 5 is a block diagram illustrating a configuration of a base station device using the receiver according to the present invention.

FIG. 6 is a block diagram illustrating a configuration of a demodulation unit according to the first embodiment.

FIG. 7 is a diagram showing a state of a received signal in the embodiment.

FIG. 8 is a diagram for explaining a demodulation operation in the embodiment.

FIG. 9 is a block diagram showing a configuration of a conventional frequency hopping communication type transmitter.

FIG. 10 is a diagram for explaining switching of the oscillation frequency of the synthesizer.

[Explanation of symbols]

1, 2,..., Base station apparatus, 12, 24,.
3a: primary modulation section, 13b, 22b: oscillator, 13
c, 22c Multiplier, 13d, 22a Band filter, 13e Amplifier, 21 Receiver, 22d Detector, 100 Switch, 111-116, 231-2
36 switching part, 131 to 13n modulation part, 221 to
22n... Demodulation unit.

Claims (6)

[Claims] 1. A plurality of modulating means for modulating a carrier wave having a different frequency with a modulating signal and outputting the modulated signals, and sequentially selecting the plurality of modulating means in accordance with a hopping pattern. A transmitter, comprising: switching means for supplying a signal; and transmission means for transmitting output signals from the plurality of modulation means. 2. The apparatus according to claim 1, wherein said switching means is provided for a plurality of channels, and each switching means sequentially selects said plurality of modulation means in accordance with one of a plurality of hopping patterns which do not overlap with each other. Transmitter. 3. A demodulator for demodulating a data signal carried on a carrier wave of a specific frequency from a received signal for each of a plurality of different carrier wave frequencies; And a selecting means for sequentially selecting the data and outputting a data signal from the selected demodulator. 4. The apparatus according to claim 3, wherein said selecting means is provided for a plurality of channels, and each selecting means sequentially selects said plurality of demodulators according to any of a plurality of hopping patterns which do not overlap with each other. Receiver. 5. A base station apparatus comprising a transmitter and a receiver for communicating with a mobile station apparatus, wherein the transmitter modulates a carrier having a different frequency with a modulation signal and outputs the modulated carrier. Modulating means, a plurality of modulating means are sequentially selected according to a hopping pattern, a switching means for supplying a data signal as the modulating signal to the selected modulating means, and an output signal from the plurality of modulating means is transmitted. Transmitting means, the receiver comprising: a demodulator for providing a demodulator for demodulating a data signal carried on a carrier of a specific frequency from a received signal for each of a plurality of different carrier frequencies; and a hopping pattern. Selecting means for sequentially selecting the plurality of demodulators according to the following formulas and outputting data signals from the selected demodulators. 6. The apparatus according to claim 1, wherein each of said switching means and said selection means is provided for a plurality of channels, and said switching means sequentially selects said plurality of modulation means according to any of a plurality of hopping patterns which do not overlap with each other. The base station apparatus according to claim 5, wherein the means sequentially selects the plurality of demodulators according to any of the plurality of hopping patterns.