JP2017147676A - Communication apparatus and wireless transmission method - Google Patents

Abstract

Provided are a communication device and a wireless transmission method capable of calculating an appropriate transmission weight when the number of antennas for receiving signals and the number of antennas for transmitting signals are different, and capable of performing better wireless communication. The purpose is to do.
The configuration of a base station 100 is such that an adaptive array communication device having a plurality of reception-dedicated antennas 4a and 4b and a plurality of transmission / reception antennas 6a and 160b is based on the reception signals of the reception-dedicated antenna and the transmission / reception antenna. An adaptive array processing unit 14 for calculating a reception weight, an adaptive array processing unit 18 for calculating a transmission weight from a reception signal of a transmission / reception antenna, and an adaptive array processing unit for performing transmission in an adaptive array system using a transmission weight 18.
[Selection] Figure 1

Description

  The present invention relates to an adaptive array communication device and a wireless transmission method in the communication device.

  A base station that employs an adaptive array system that uses multiple antennas estimates the reception timing of the received signal input to each antenna with high accuracy and executes synchronization processing. Based on each signal that has been subjected to synchronization processing, Thus, the reception weight is calculated, and the signal is transmitted with the transmission weight based on the reception weight (for example, Patent Document 1).

  In recent years, an adaptive array base station equipped with a reception-only antenna and a transmission / reception antenna has been studied to reduce the number of transmission circuits in order to reduce the cost of the base station. Specifically, all antennas (for example, 4) are used for reception as usual, but only some antennas (for example, 2) are used for transmission. Since one transmission circuit is required for each antenna, reducing the number of antennas used for transmission and reducing the number of transmission circuits have the same meaning. In this application, an antenna that transmits and receives signals is called a transmitting / receiving antenna, and an antenna that only receives signals is called a reception-only antenna. Signal reception is performed using a transmission / reception antenna and a reception-dedicated antenna, and signal transmission is performed using a transmission / reception antenna.

JP 2004-153527 A

  However, the reception weight generated using the reception signals of the transmission / reception antenna and the reception-dedicated antenna may not be appropriate as a transmission weight when transmitting using only the transmission / reception antenna.

  In view of such problems, an object of the present invention is to provide a communication device and a wireless transmission method that can calculate an appropriate transmission weight and can perform better wireless communication.

  In order to solve the above problems, a typical configuration of a communication apparatus according to the present invention is a synchronization apparatus for transmission that performs a synchronization process of a reception signal of the transmission / reception antenna in a communication apparatus including a reception-only antenna and a transmission / reception antenna. A directional beam is transmitted using the processing unit, a transmission processing unit for obtaining a transmission weight obtained from the synchronization of the transmission synchronization processing unit, and the transmission weight.

  The configuration of the communication apparatus according to the present invention includes: a reception synchronization processing unit that performs synchronization processing of reception signals of the reception dedicated antenna and the transmission / reception antenna; and reception for obtaining a weight obtained from synchronization of the reception synchronization processing unit And a processing unit.

  The configuration of the communication apparatus according to the present invention compares the weight data obtained from the synchronization of the transmission synchronization processing unit with the weight data obtained from the synchronization of the reception synchronization processing unit. A control unit for selecting a good weight may be provided.

  The configuration of the communication device according to the present invention includes an additional transmission processing unit for obtaining a transmission weight obtained from the synchronization of the reception synchronization processing unit, and synchronization by the reception synchronization processing unit or by the transmission synchronization processing unit One of the synchronizations may be selected.

  The configuration of the communication device according to the present invention may be selected from either synchronization by the reception synchronization processing unit or synchronization by the transmission synchronization processing unit in accordance with radio quality of transmission of the communication device.

  In order to solve the above problems, a representative configuration of a radio transmission method according to the present invention is a radio transmission method of a communication apparatus including a reception-dedicated antenna and a transmission / reception antenna, and a synchronization process of a reception signal of the transmission / reception antenna , A step of obtaining a transmission weight obtained from the synchronization of the steps, and a step of transmitting a directional beam using the transmission weight.

  According to the present invention, it is possible to provide a communication device and a wireless transmission method capable of calculating an appropriate transmission weight and capable of performing better wireless communication.

It is a functional block diagram which illustrates the composition about the base station which is a communication apparatus of a 1st embodiment. It is a functional block diagram which illustrates the structure about the base station which is a communication apparatus of 2nd Embodiment. It is a flowchart which shows the flow of a process in the base station which is a communication apparatus of 2nd Embodiment. It is a functional block diagram which illustrates the structure about the base station provided with the antenna only for receiving and the antenna for both transmitting and receiving.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  Hereinafter, after describing the base station 10 with reference to FIG. 4, the base station as the communication apparatus of the present embodiment will be described.

  The base station 10 is an adaptive array type base station having a reception-only antenna and a transmission / reception antenna. Specifically, all antennas (for example, 4) are used for reception as usual, but only some antennas (for example, 2) are used for transmission. Since one transmission circuit is required for each antenna, reducing the number of antennas used for transmission and reducing the number of transmission circuits have the same meaning. In this application, an antenna that transmits and receives signals is called a transmitting / receiving antenna, and an antenna that only receives signals is called a reception-only antenna. Signal reception is performed using a transmission / reception antenna and a reception-dedicated antenna, and signal transmission is performed using a transmission / reception antenna.

  FIG. 4 is a functional block diagram illustrating the configuration of the base station 10. As shown in FIG. 4, the base station 10 includes antennas 4a, 4b, 6a, and 6b. Of these, the two antennas 4a and 4b are reception-only antennas, and the remaining two antennas 6a and 6b are transmission / reception antennas. In the base station 10, signals from the terminals are received by the antennas 4a, 4b, 6a, and 6b. A signal received from the terminal (hereinafter referred to as a received signal) is sent to the synchronization processing unit 12, and the synchronization processing unit 12 performs synchronization processing on the reception timing of the received signal by feedback from the adaptive array processing unit 14.

  The adaptive array processing unit 14 calculates reception weights from the reception signals of the antennas 4a, 4b, 6a, and 6b subjected to the synchronization processing. The demodulator 15 demodulates the received signal that has been subjected to adaptive array processing into data, and outputs the data to the controller 17.

  On the other hand, the adaptive array processing unit 18 calculates a transmission weight from the reception signals of the antennas 6a and 6b subjected to the synchronization process. The transmission weight is fed back to the antennas 6a and 6b that transmit the transmission data. As a result, signals are transmitted from 6a and 6b to the terminal using the transmission weight. Note that an electric circuit for transmitting transmission data is omitted.

  That is, the base station 10 shown in FIG. 4 establishes the synchronization position (synchronization timing) using the received signals received by the four antennas despite the transmission of the signals by the two antennas 6a and 6b. The weight (weight coefficient) is calculated using the synchronization position as the start position. In this situation, when the radio signal from the terminal is reflected on an obstacle and a delayed wave is generated, the accuracy of the synchronization position is reduced under conditions where the communication quality varies greatly. The transmission weight sometimes used is also affected, and the transmission performance is deteriorated.

  When the reception-only antenna is dominant (the reception signal strength is strong), a synchronization position with respect to the reception-only antenna is established, and a transmission weight is calculated based on the synchronization position. Since this transmission weight is almost based on the reception-only antenna reference at the synchronization position, if it is applied to the transmission / reception antenna as it is at the time of transmission, there is no reference (maximum value), and only the weight for the deviation is obtained. As a result, the original adaptive array performance cannot be exhibited at the time of transmission, resulting in degradation of transmission performance, and eventually degradation of reception quality of the opposite terminal, leading to a decrease in communication area.

  In the embodiment described below, a base station is exemplified as a communication device. However, in the base station according to the embodiment of the present invention, in view of such a problem, the number of antennas that receive a signal is different from the number of antennas that transmit a signal. It is an object of the present invention to provide a communication apparatus and a wireless transmission method capable of calculating a transmission weight of an appropriate directional beam and capable of performing better wireless communication.

(First embodiment)
FIG. 1 is a functional block diagram illustrating the configuration of a base station 100 that is a communication device according to the first embodiment. Hereinafter, the base station 100 of this embodiment is demonstrated. In addition, about the component which is common in the base station 10 demonstrated above, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  As shown in FIG. 1, the base station 100 of the first embodiment includes reception-only antennas 4a and 4b and transmission / reception antennas 6a and 6b, and uses these antennas to communicate with a terminal in an adaptive array system. Specifically, the base station 100 receives signals from the terminals using four antennas, that is, the reception-only antennas 4a and 4b and the transmission / reception antennas 6a and 6b, and transmits the signals to the terminals. This is performed using two antennas 6a and 6b. In addition, the base station 100 performs signal transmission / reception (wireless communication) with a terminal using time-division duplex (TDD) using the reception-only antennas 4a and 4b and the transmission / reception antennas 6a and 6b.

  A signal received from the terminal (hereinafter referred to as a received signal) is sent to the synchronization processing unit 12, and the synchronization processing unit 12 performs synchronization processing on the reception timing of the received signal by feedback from the adaptive array processing unit 14.

  The adaptive array processing unit 14 (reception processing unit) calculates reception weights from the reception signals of the antennas 4a, 4b, 6a, and 6b subjected to the synchronization processing. The demodulating unit 15 demodulates the received signal subjected to the adaptive array processing by the adaptive array processing unit 14 into data, and outputs the data to the control unit 170.

  The base station 100 includes a synchronization processing unit 110 and an adaptive array processing unit 18. The synchronization processing unit 110 performs synchronization processing of received signals of only the transmission / reception antennas 6a and 6b among the four antennas of the reception-only antennas 4a and 4b and the transmission / reception antennas 6a and 6b. Synchronization processing of the reception timing of the received signal by feedback of the adaptive array processing unit 18 is performed in the synchronization processing unit 110.

  A synchronization processing unit 12 that synchronizes the reception signals of the reception antennas 4a, 4b, 6a, and 6b under a situation where the communication quality varies greatly, such as when a delayed signal is generated by reflection of a radio signal from the terminal. The synchronization position of the synchronization processor 110 that synchronizes the received signals of the transmitting / receiving antennas 6a and 6b is different.

  The adaptive array processing unit 18 (transmission processing unit) calculates a transmission weight for forming a directional beam by performing synchronization processing from the received signals of the transmitting / receiving antennas 6a and 6b. The demodulator 19 demodulates the received signal that has been subjected to the adaptive array processing by the adaptive array processor 18 into data, and outputs the data to the controller 170. In addition, the adaptive array processing unit 18 reflects the transmission weight calculated by the adaptive array processing unit 18 on the transmitting / receiving antennas 6a and 6b.

  The controller 170 may compare the data demodulated by the demodulator 15 with the data demodulated by the demodulator 19 and select a weight with good quality to be received data. Here, if the quality of the data demodulated by the demodulator 19 is good, the adaptive array processor 18 may reflect the transmission weight calculated by the adaptive array processor 18 on the transmitting / receiving antennas 6a and 6b.

  As a result, a radio signal is transmitted from the transmitting / receiving antennas 6a and 6b to the terminal using the transmission weight, and communication in which the performance of the adaptive array is appropriately exhibited is performed.

  As described above, the base station 100 according to the first embodiment calculates the transmission weight using the reception signals of only the transmission / reception antennas 6a and 6b used for transmission in addition to the conventional reception weight. The transmission weight is a weight calculated without using the reception signals of the reception-only antennas 4a and 4b. Therefore, the base station 100 can transmit a signal to the terminal with a weight excluding the influence of the reception-only antennas 4a and 4b.

(Second Embodiment)
FIG. 2 is a functional block diagram illustrating the configuration of the base station 200 that is the communication apparatus according to the second embodiment. In addition, about the component which is common in the base station 10 demonstrated above and the base station 100 of 1st Embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In the base station 100 of the first embodiment, the adaptive array processing unit 18 for calculating the transmission weight is provided, whereas in the base station 200 of the second embodiment shown in FIG. 2, the base station shown in FIG. 10, a synchronization processing unit 210 and an adaptive array processing unit 220 are added.

  The synchronization processing unit 210 performs synchronization processing of received signals of only the transmission / reception antennas 6a and 6b among the four antennas, that is, the reception dedicated antennas 4a and 4b and the transmission / reception antennas 6a and 6b. Synchronization processing of the reception timing of the received signal based on feedback from the adaptive array processing unit 220 is performed by the synchronization processing unit 210. The synchronization of the synchronization processing unit 210 is reflected in the synchronization processing unit 12.

  Here, the flow of processing in the second embodiment is shown. FIG. 3 is a flowchart showing a flow of processing in the base station which is the communication apparatus of the second embodiment.

  First, a link channel request is made from the terminal 1 to the base station 200 (step S1). The base station 200 allocates the link channel of the terminal 1 and notifies the allocated channel (step S2). Normally, the base station 200 calculates reception weights and transmission weights in the adaptive array processing unit 14 and the adaptive array processing unit 18 with reference to the timing of the synchronization processing unit 12.

  The terminal 1 confirms whether or not the radio quality of the assigned channel is deteriorated (step S3), and if the radio quality is not deteriorated, the terminal 1 continues the communication with the base station 200 as it is. If the radio quality has deteriorated, the terminal 1 notifies the base station 200 of the radio quality deterioration (step S4).

  Radio quality includes signal-to-interference and noise ratio (SINR), received signal strength indicator (RSSI), signal-to-interference ratio (SIR), and signal-to-noise ratio (SNR). A bit error rate (BER) or a frame error rate (FER) can be exemplified.

  At this time, the base station 200 establishes a synchronization position (synchronization timing) using the received signals received by the four antennas, although the signals are transmitted by the two antennas 6a and 6b. The weight (weighting coefficient) is calculated using as a starting position. In this situation, when the wireless signal from the terminal 1 is reflected on an obstacle and a delayed wave is generated, the accuracy of the synchronization position is reduced under a situation where the communication quality varies greatly. The transmission weight used at the time of transmission is also affected, and transmission performance is degraded.

  The base station 200 calculates the reception weight and the transmission weight in the adaptive array processing unit 14 and the adaptive array processing unit 18 with reference to the timing of the synchronization processing unit 12, but has received a notification of radio quality deterioration from the terminal 1. Switch to the timing of the synchronization processing unit 210 (step S5). That is, the synchronization is switched from the synchronization of the antennas 4a, 4b, 6a, and 6b to the synchronization of the reception signals of only the transmitting / receiving antennas 6a and 6b. When the wireless quality returns to a good state, the antennas 4a, 4b, 6a, and 6b may be switched to synchronization.

  The base station 200 can calculate an appropriate transmission weight by switching to the synchronization processing based on the transmission / reception antenna, and can perform better wireless communication. Further, when the terminal 1 moves and the wireless communication quality deteriorates, the synchronization processing is switched and the transmission weight is recalculated, so that the communication quality can be maintained.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  INDUSTRIAL APPLICABILITY The present invention can be used in an adaptive array communication device including a plurality of reception-dedicated antennas and a plurality of transmission / reception antennas and a wireless transmission method thereof.

DESCRIPTION OF SYMBOLS 10, 100, 200 ... Base station, 12, 110, 210 ... Synchronization processing part, 14, 18 ... Adaptive array processing part, 15, 19 ... Demodulation part, 17, 170, 270 ... Control part, 1 ... Terminal, 4a ... Receive-only antenna, 4b ... Receive-only antenna, 6a ... Transmit / receive antenna, 6b ... Transmit / receive antenna

Claims (6)

In a communication device equipped with a receive-only antenna and a transmitting / receiving antenna,
A synchronization processing unit for transmission that performs synchronization processing of a reception signal of the antenna for both transmission and reception;
A transmission processor for obtaining a transmission weight obtained from the synchronization of the transmission synchronization processor;
A communication apparatus for transmitting a directional beam using the transmission weight. A reception synchronization processing unit that performs synchronization processing of reception signals of the reception dedicated antenna and the transmission / reception antenna;
A reception processing unit for obtaining a weight obtained from the synchronization of the reception synchronization processing unit;
The communication apparatus according to claim 1, further comprising:   A control unit is provided that compares the data based on the weight obtained from the synchronization of the synchronization processing unit for transmission with the data based on the weight obtained from the synchronization of the synchronization processing unit for reception, and selects a quality weight. The communication apparatus according to claim 2. An additional transmission processor for obtaining a transmission weight obtained from the synchronization of the reception synchronization processor;
The communication apparatus according to claim 2, wherein either the synchronization by the reception synchronization processing unit or the synchronization by the transmission synchronization processing unit is selected.   The communication apparatus according to claim 4, wherein either the synchronization by the reception synchronization processing unit or the synchronization by the transmission synchronization processing unit is selected according to radio quality of transmission of the communication apparatus. In a wireless transmission method of a communication device provided with a reception dedicated antenna and a transmission / reception antenna,
Performing a synchronization process of a received signal of the transmitting / receiving antenna;
Obtaining a transmission weight obtained from the synchronization of the steps;
And a radio transmission method including transmitting a directional beam using the transmission weight.

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