JP2001257660A - Transmission device, reception device, and transmission / reception method - Google Patents

Abstract

(57) [Problem] To provide a diversity effect of compensating for fading fluctuation with a delay time equivalent to a spreading rate without increasing the device scale, thereby improving transmission characteristics. SOLUTION: A spreading section 103 spreads transmission data with a spreading code, a first radio transmission section 105 modulates a carrier with the spread transmission data and transmits the modulated data, and a delay section 104 delays the spread transmission data by a predetermined time. Then, the second radio transmitting section 106 modulates the carrier with the delayed signal and transmits the modulated signal.
Then, the received signal is demodulated by combining both transmission signals,
The first despreading unit 111 despreads the demodulated signal with the same spreading code as that of the transmitting side, delays the time by the same time as that of the transmitting side in the delay unit 113, and demultiplexes the demodulated signal in the second Despreading is performed at a timing delayed by a predetermined time with the same spreading code, and the data obtained by the despreading and the delayed data are combined by the combining unit 114 to obtain received data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code division multiplexing (CDMA) system used in digital mobile communication and the like.
The present invention relates to a transmitting device, a receiving device, and a transmitting / receiving method suitable for use in a mobile station device such as a mobile phone or an information terminal device having a mobile phone function, or a base station device performing wireless communication with the mobile station device.

[0002]

2. Description of the Related Art Conventionally, as this kind of transmitting apparatus, receiving apparatus, and transmitting / receiving method, one described in Japanese Patent Application Laid-Open No. 9-181662 is known.

FIG. 2 is a block diagram showing a configuration of a transmitting apparatus and a receiving apparatus to which a conventional CDMA system is applied.

The transmitting apparatus 201 and the receiving apparatus 202 shown in FIG. 2 are applied to, for example, a mobile station apparatus or a base station apparatus in a mobile communication system. In this example, the transmitting apparatus 201 is used as a mobile station apparatus. It is assumed that the receiving device 202 is applied to a base station device. Note that the reverse application may be applied.

[0005] The transmitting apparatus 201 includes a spreading section 203, a delay section 204, an adding section 205, a radio transmitting section 206, and a transmitting antenna 207.

[0006] The receiving device 202 includes a receiving antenna 208.
, A detection unit 209, a first despreading unit 210, a second despreading unit 211, a delay unit 212, and a combining unit 213.

In such a configuration, first, in transmitting apparatus 201, transmission data is spread with a predetermined spreading code in spreading section 203, and after this spread transmission data is delayed for a predetermined time T in delay section 204, , Adder 2
05 is output.

[0008] The adder 205 adds the pre-delay and post-delay spread transmission data, modulates the added transmission data to a radio frequency in the radio transmitter 206, and then transmits the radio wave from the transmission antenna 207. You.

[0009] This transmission signal is propagated through propagation path 214 and received by transmission antenna 207 of receiving apparatus 202. The signal received by the transmission antenna 207 is demodulated by quasi-synchronous detection in the detection unit 209, and the first
And output to the second despreading units 210 and 211.

In the first despreading section 210, the demodulated received signal is despread with the same spreading code as that on the transmitting side, and the received data obtained by this is transmitted to a delay section 212, which is the same as the delay section 204 on the transmitting side. A time delay T is set. The data after the delay is defined as first received data.

On the other hand, in the second despreading section 211, the detecting section 2
09 is despread with a spreading code delayed by a predetermined time T with respect to the first despreading unit 210, and the second reception data obtained by this is output to the combining unit 213.
The received data is combined with the first received data, thereby obtaining received data having a diversity effect.

[0012]

However, in the conventional apparatus, since the transmitting apparatus 201 transmits the delayed wave to the same propagation path 214 as the direct wave, the delayed wave is also deteriorated by the same fading fluctuation as the direct wave. Will occur.

For this reason, in order to complement the deterioration due to fading fluctuation between the direct wave and the delayed wave, a large delay with respect to the fading frequency (several Hz to several hundred Hz) is required.
It must be set in the delay units 204 and 214.

[0014] When such a large delay is set, the transmission characteristics are degraded, and there is a problem that the user feels an unnatural voice delay in voice communication. Also, since the delay time must be increased, the delay units 204 and 2
For example, there is a problem that the memory capacity or the like used for the memory 14 becomes large, and accordingly, the device scale becomes large.

The present invention has been made in view of the above point, and can obtain a diversity effect of compensating for fading fluctuation with a delay time equal to the spreading rate without increasing the size of the device, thereby achieving transmission characteristics. It is an object of the present invention to provide a transmission device, a reception device, and a transmission / reception method that can improve the performance.

[0016]

A transmitting apparatus according to the present invention comprises: a spreading means for spreading transmission data with a spreading code; a delay means for delaying the spread transmission data for a predetermined time to output a delay signal; A first radio unit for modulating a carrier with the spread transmission data and transmitting a first transmission signal; and a second radio unit for modulating the carrier with the delay signal and transmitting a second transmission signal. A transmission device characterized by the above-mentioned.

According to this configuration, the direct wave and the delayed wave obtained by modulating the same transmission data are transmitted from separate antennas having a small fading correlation, so that they can be transmitted on different propagation paths.

[0018] A receiving apparatus according to the present invention combines a first transmission signal and a second transmission signal transmitted from the transmission apparatus according to claim 1 and demodulates the received signal, and detects the demodulated signal on the transmission side. First despreading means for despreading with the same spreading code, second despreading means for despreading the demodulated signal at a timing delayed by a predetermined time with the spreading code, and despreading by the first despreading means. Delay means for delaying the data obtained by spreading the same time as the delay means of the transmitting device; and synthesizing the delayed data from this delay means and the data obtained by despreading by the second despreading means. And a combining unit.

According to this configuration, the data modulated into the direct wave and the delayed wave transmitted via the independent propagation paths are:
Since they are individually obtained by modulation and despreading and then combined, it is possible to obtain received data with a diversity effect, thereby improving transmission characteristics,
Further, since the propagation path is independent, the fading fluctuation is also independent, so that a diversity effect can be obtained regardless of the magnitude of the delay time.

A mobile station device according to the present invention includes the transmitting device according to claim 1 or the receiving device according to claim 2.

According to this configuration, in the mobile station device,
The same operation and effect as those of the transmission device or the reception device having the above configuration can be obtained.

A base station apparatus according to the present invention includes the transmitting apparatus according to claim 1 or the receiving apparatus according to claim 2.

According to this configuration, in the base station apparatus,
The same operation and effect as those of the transmission device or the reception device having the above configuration can be obtained.

The mobile communication system according to the present invention is described in claim 3.
A mobile communication system comprising the mobile station device according to claim 4 or the base station device according to claim 4.

According to this configuration, in the mobile communication system, the same operation and effect as those of the mobile station device or the base station device having the above configuration can be obtained.

According to the transmission / reception method of the present invention, transmission data is spread with a spreading code, a carrier is modulated with the spread transmission data, a first transmission signal is transmitted, and the spread transmission data is delayed by a predetermined time. The carrier is modulated with the obtained delay signal, a second transmission signal is transmitted, the first and second transmission signals are combined to demodulate the received signal, and the demodulated signal is despread with the spreading code. And transmitting and receiving the delayed data and the data obtained by despreading the demodulated signal at a timing delayed by the spreading code for a predetermined time.

According to this method, the direct wave and the delay wave modulated by the same transmission data can be transmitted on different propagation paths, respectively, and the direct wave and the delay wave transmitted through the propagation paths can be transmitted. The modulated data is individually obtained by modulation and despreading and then combined, so that it is possible to obtain received data having a diversity effect, thereby improving transmission characteristics, and further enabling independent propagation paths. Therefore, since the fading fluctuation is independent, the diversity effect can be obtained regardless of the magnitude of the delay time.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment) FIG. 1 is a block diagram showing a configuration of a transmitting apparatus and a receiving apparatus according to an embodiment of the present invention.

The transmitting apparatus 101 and the receiving apparatus 102 shown in FIG. 1 are applied to, for example, a mobile station apparatus or a base station apparatus in a mobile communication system. In this example, the transmitting apparatus 101 is used as a mobile station apparatus. It is assumed that receiving apparatus 102 is applied to a base station apparatus. Note that the reverse application may be applied.

The transmitting apparatus 101 includes a spreading section 103, a delay section 104, a first wireless transmitting section 105, a second wireless transmitting section 106, and first and second transmitting antennas 107 and 108. ing.

The receiving apparatus 102 includes a receiving antenna 109
, A detection unit 110, a first despreading unit 111, a second despreading unit 112, a delay unit 113, and a combining unit 114.

In such a configuration, first, in transmitting apparatus 101, transmission data is spread by spreading section 103 using a predetermined spreading code assigned to each channel, and the spread transmission data is transmitted to first radio transmission section 101. At 105, the signal is modulated with a carrier wave and transmitted from the first transmitting antenna 107 by radio wave.

On the other hand, the transmission data spread by spreading section 103 is delayed for a predetermined time t by delay section 104, and the delayed transmission data is modulated by a second radio transmission section 106 with a carrier wave, and transmitted by a first transmission antenna. Radio waves are transmitted from the second transmission antenna 108 having a small fading correlation with respect to 107.

The transmission signal transmitted from first transmission antenna 107 is propagated via first propagation path 115, and the transmission signal transmitted from second transmission antenna 108 is propagated via second propagation path 116. , Are transmitted and received by the receiving antenna 109 of the receiving apparatus 102.

The received signal is demodulated by quasi-synchronous detection in the detection unit 110 and output to the first and second despreading units 111 and 112.

In the first despreading section 111, the received signal is despread with the same spreading code as that on the transmitting side, and the received data obtained by this is delayed by the delay section 113 by the same time t as the delay section 104 on the transmitting side. Can be The data after the delay is defined as first received data.

On the other hand, in the second despreading section 112, the received signal is despread by the first despreading section 111 with a spreading code delayed by a predetermined time t, and the second received data obtained thereby is synthesized. In the unit 114, the received data is combined with the first received data, thereby obtaining received data having a diversity effect.

As described above, the transmitting apparatus 10 of the present embodiment
1 and the receiving device 102, the direct wave and the delayed wave transmitted from the transmitting device 101 are transmitted to the receiving device 102 via two independent first and second propagation paths 115 and 116, and the receiving device 102 Then, the first and second propagation paths 115,
First and second despreading units 111 and 112 corresponding to 116
Despreading, and one of the data after despreading is
In 04, the data is delayed by the same delay time t as the delay on the transmission side, and the data after the delay and the data after the despreading are combined, so that received data having a diversity effect can be obtained, and the transmission characteristics can be improved. Since the propagation paths 115 and 116 are independent, fading fluctuations are also independent, so that a diversity effect can be obtained regardless of the size of the delay time t.

Therefore, the transmission characteristics deteriorate as in the prior art,
In the voice communication, an unnatural voice delay is not felt by the user, and the delay time t can be reduced, so that the delay units 104 and 113 can be reduced. Can be smaller.

[0041]

As described above, according to the present invention,
It is possible to obtain a diversity effect of compensating for fading fluctuation with a delay time equal to the spreading rate without increasing the device scale, thereby improving transmission characteristics.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a transmitting device and a receiving device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a conventional transmitting device and a conventional receiving device.

[Explanation of symbols]

 Reference Signs List 101 transmitting device 102 receiving device 103 spreading unit 104, 113 delay unit 105 first wireless transmitting unit 106 second wireless transmitting unit 107 first transmitting antenna 108 second transmitting antenna 109 receiving antenna 110 detecting unit 111 first despreading unit 112 first 2 despreading unit 114 combining unit 115 first propagation path 116 second propagation path

Claims (6)

[Claims] 1. A spreading means for spreading transmission data with a spreading code, a delay means for delaying the spread transmission data for a predetermined time and outputting a delay signal, and a carrier wave modulated by the spread transmission data. A transmission apparatus comprising: a first wireless unit that transmits a first transmission signal; and a second wireless unit that modulates a carrier with the delay signal and transmits a second transmission signal. 2. A detection means for combining the first and second transmission signals transmitted from the transmission apparatus according to claim 1 and demodulating a received signal, and using the same spreading code as that of a transmission side for the demodulated signal. First despreading means for despreading, second despreading means for despreading the demodulated signal at a timing delayed by the spreading code for a predetermined time, and despreading by the first despreading means. Delay means for delaying the data by the same time as the delay means of the transmitting device; and synthesizing means for synthesizing the delayed data from the delay means and the data obtained by despreading in the second despreading means. A receiving device, comprising: 3. A mobile station device comprising the transmitting device according to claim 1 or the receiving device according to claim 2. 4. A base station device comprising the transmitting device according to claim 1 or the receiving device according to claim 2. 5. The mobile station device according to claim 3, or claim 4.
A mobile communication system comprising the base station apparatus according to any one of the preceding claims. 6. A delay signal obtained by spreading transmission data with a spreading code, modulating a carrier with the spread transmission data, transmitting a first transmission signal, and delaying the spread transmission data by a predetermined time. Modulates the carrier to transmit a second transmission signal, synthesizes the first and second transmission signals, demodulates the received signal, despreads the demodulated signal with the spreading code, and sets the same as the delay. A transmission / reception method, wherein the transmission / reception method delays the time and combines the delayed data with data obtained by despreading the demodulated signal with the spread code at a predetermined time.