KR100744430B1 - Radio relay device having multi-antennas for echo cancellation and method thereof - Google Patents

Abstract

A wireless repeater having plural antennas and a wireless relay method are provided to select and relay a non-oscillation signal among plural combination receiving signals, thereby eliminating an echo signal component at a low cost and in a simple structure since a high-priced DSP(Digital Signal Processor) for removing the echo signal is not equipped. A receiving antenna unit(210) consists of N antennas(211,212,213) separated from each other, and receives N non-combination receiving signals. A receiving signal combiner(220) generates M combination receiving signals by using a method of combining at least two signals of the non-combination receiving signals. A relay signal selector(230) selects at least more than one non-oscillation receiving signal of the M combination receiving signals and the N non-combination receiving signals, and generates a relay signal.

Description

Radio Relay Device Having Multi-Antennas for Echo Cancellation and Method Thereof}

1 is a configuration diagram of a relay environment of a wireless repeater.

2 is a block diagram of an ICS wireless repeater having an echo cancellation digital signal processor according to the prior art.

Figure 3a is a block diagram of a relay environment of a two-way wireless repeater according to the present invention.

Figure 3b is a block diagram of a relay environment of the unidirectional wireless repeater according to the present invention.

4 is a block diagram of a wireless repeater according to an embodiment of the present invention.

5 is a detailed configuration diagram of a reception signal coupling unit according to an embodiment of the present invention.

6 is a detailed configuration diagram of a relay signal selection unit according to an embodiment of the present invention.

7 is a detailed configuration diagram of a transmitting antenna unit according to an embodiment of the present invention.

8 is a processing flowchart of a wireless relay method according to an embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

210: receiving antenna unit 220: receiving signal coupling unit

230: relay signal selector 280: power amplifier

290 transmit antenna

The present invention relates to a wireless repeater having a plurality of antennas and a wireless relay method, and more particularly, to select and relay a non-oscillating signal from a signal received from a plurality of antennas and a combined received signal generated by combining each received signal. The present invention relates to a wireless repeater and a wireless relay method for transmitting signals.

As various wireless communication services such as CDMA, Wibro, and DMB are provided, the necessity of a wireless repeater for expanding the wireless communication service area is increasing. 1 illustrates a relay operation by the wireless repeater 100. The received signal r (t) received from the base station BS is retransmitted by the repeater 100 as a relay signal s (t) to the mobile station MS in the radio shaded area or the radio wave weakened area. The signal received from the Rx is also transmitted to the base station BS as the relay signal s (t). However, since the reception signal r (t) received by the repeater 100 and the relay signal s (t) transmitted by the repeater 100 have the same frequency, some of the signals output by the transmitting antenna are used. May be directly or reflected through the space and re-input as an echo signal (e (t)) through the receiving antenna. The echo signal e (t) is combined with the original signal r (t) received by the receiving antenna and output again through the transmitting antenna, and thus the wireless repeater 100 causes oscillation. . When the oscillation occurs, the specific gravity of the echo signal e (t) is gradually increased than the original signal r (t), and the characteristics of the signal received by the mobile station MS are significantly reduced.

The oscillation of the wireless repeater 100 occurs not only in the case of bidirectional relaying between the base station BS and the mobile station MS such as mobile communication and wireless internet, but also in the case of unidirectional relaying such as digital broadcasting.

Meanwhile, according to the related art, various methods for removing the echo signal e (t) from the received signal r (t) are proposed to prevent oscillation of the wireless repeater 100. 2 illustrates a configuration of a general Interference Cancellation System (ICS) repeater. The signal received through the receiving antenna unit 110 is amplified by the low noise amplifier 120. The amplified signal is converted into an intermediate frequency IF through the frequency down converter 130 and converted into a digital signal through the A / D converter 140 to facilitate signal processing. The received signal converted to digital is removed from the echo signal e (t) through the echo cancellation digital signal processor 150.

The operation of the echo cancellation digital signal processor 150 will be described below. Since the radio wave environment from which the signal transmitted from the transmitting antenna unit 150 is re-input through the receiving antenna unit 110 can be modeled by a kind of digital filter, the echo cancellation digital signal processing unit 150 echoes in consideration of the radio wave environment. The echo signal e (t) is generated by predicting the signal e (t) component and subtracting the echo signal e (t) from the received signal r (t) to generate the relay signal s (t). Excludes the effects of)).

However, according to this method, the repeater 100 includes not only the echo canceling digital signal processor 150 but also a plurality of digital signal processing components such as an A / D converter and a D / A converter. There is a problem that rises.

In addition, in a wireless environment that changes from time to time, this method has a problem of requiring a high computational processing capacity in the digital circuit of the wireless repeater 100.

Finally, since the signal processing process in the repeater 100 takes a lot of time, the mobile station MS performs multipath fading by a signal received directly from the base station BS and a signal received delayed through the repeater 100. There is a problem that the reception quality is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and includes a non-oscillation signal among a plurality of non-combined reception signals received from a plurality of reception antennas and a plurality of combined reception signals combining signals received from a plurality of antennas. It is an object of the present invention to provide a wireless repeater and a wireless relay method capable of removing echo signal components with a simple structure and low cost since it does not include an expensive digital signal processor for removing echo signals by selecting and relaying them.

According to an embodiment of the present invention, by generating a combined received signal by using a non-combined receive signal received from each receive antenna to generate more than the number of receiving antennas to receive the non-oscillating signal using a small number of multi-antennas Another object is to provide a wireless repeater and a wireless relay method that can maximize the possibility.

According to another embodiment of the present invention, another object of the present invention is to provide a wireless repeater and a wireless relay method capable of easily determining whether or not a non-oscillating signal is obtained through the magnitude and derivative of each received signal.

According to another embodiment of the present invention, a mobile station or base station having a rake receiver by selecting a plurality of non-oscillating signals as a selection signal, and part of each selection signal by delaying at least one chip or more to improve time diversity. Another object of the present invention is to provide a wireless repeater and a wireless relay method capable of improving reception quality.

According to another embodiment of the present invention, another object of the present invention is to provide a wireless repeater and a wireless relay method capable of improving reception quality by transmitting relay signals through a plurality of transmitting antennas to improve spatial diversity.

In order to achieve the above object, the wireless repeater according to the present invention comprises a receiving antenna unit consisting of N antennas spaced apart from each other to receive N non-combined reception signals; A received signal combiner configured to generate M combined received signals by combining at least two signals among the uncombined received signals; And a relay signal selector configured to generate a relay signal by selecting at least one non-oscillation received signal among the N uncoupled received signals and the M combined received signals.

A wireless repeater according to an embodiment of the present invention includes a first receiving antenna for receiving a first uncombined reception signal, a second receiving antenna for receiving a second uncombined reception signal, and a third for receiving a third uncombined reception signal. A receiving antenna unit comprising a receiving antenna and a fourth receiving antenna for receiving the fourth uncoupled receiving signal; Combining the first uncombined reception signal with the second uncombined reception signal to combine a first combined reception signal, the first uncombined reception signal and the third uncombined reception signal, and a second combined reception signal; A second combined received signal and the third uncoupled received signal are combined to combine a third combined received signal, the second uncoupled received signal and the fourth non-coupled received signal, and a fourth combined received signal and the third non-coupled received signal; A combination of a combined received signal and the fourth uncombined received signal to combine a fifth combined received signal, the first uncombined received signal and the fourth uncombined received signal to generate a sixth combined received signal, respectively; part; And a relay signal selector configured to generate a relay signal by selecting at least one of the first non-combined reception signal and the fourth non-combination reception signal and the first combined reception signal and the sixth combined reception signal, which are not oscillated. It characterized by including.

Finally, a wireless relay method according to an embodiment of the present invention, the first step of receiving a plurality of uncombined reception signals through a plurality of receiving antennas; A second step of generating a plurality of combined reception signals by combining at least two of the plurality of uncombined reception signals; A third step of generating a relay signal by selecting at least one received signal among the plurality of uncombined received signals and the non-oscillated signal among the plurality of combined received signals; And a fourth step of amplifying the relay signal and transmitting the same through the transmitting antenna.

The above and other objects and features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3A and 3B illustrate a relay environment by a wireless repeater according to the present invention. 3A illustrates an embodiment in which a two-way relay is performed, such as a mobile communication repeater or a wireless Internet repeater, and FIG. 3B illustrates an embodiment in which a one-way relay is performed, such as digital multimedia broadcasting. The wireless repeater 200 according to the present invention includes a plurality of reception antennas R1, R2, R3, and R4, and preferably includes a plurality of transmission antennas T1 and T2.

Each antenna is arranged in consideration of a distance, an angle, and a direction with little correlation between the plurality of antennas in consideration of a radio wave environment and a frequency environment. As illustrated, the spatial diversity of the repeater 200 is improved by including the plurality of receiving antennas R1, R2, R3, and R4, and when the plurality of transmitting antennas T1 and T2 are also provided, the receiving end (MS or Space diversity in BS) is improved.

That is, according to the wireless repeater 200 of the present invention, the plurality of reception antennas R1, R2, R3, and R4 provide a higher probability of receiving a signal with less echo signal components than using a single reception antenna. do.

4 shows a configuration of the wireless repeater 200 of the present invention. The wireless repeater 200 according to the embodiment of the present invention includes a reception antenna unit 210, a reception signal coupling unit 220, a relay signal selection unit 230, a power amplifier 280, and a transmission antenna unit 290. Can be configured.

The reception antenna unit 210 receives a plurality of reception signals rcv_signal by including a plurality of reception antennas R1, R2, R3, and R4 spaced apart from each other. In order to distinguish between the combined reception signal c_signal generated by the reception signal combiner 220 to be described later and the reception signal rcv_signal directly received through the reception antennas R1, R2, R3, and R4, the reception signal is described below. This is referred to as an uncoupled reception signal (rcv_signal).

The reception signal combiner 220 generates a plurality of combined reception signals c_signal by combining at least two non-combined reception signals rcv_signal with each other as shown in the embodiment shown in FIG. 5. 5 illustrates a case in which the repeater 200 includes four antennas, and the reception signal combiner 220 combines the first uncombined reception signal rcv_signal_1 and the second uncombined reception signal rcv_signal_2. The first combined reception signal c_signal_1, the first uncombined reception signal rcv_signal_1 and the third uncombined reception signal rcv_signal_3 are combined to form the second combined reception signal c_signal_2, the second uncombined reception signal rcv_signal_2 and the first combination. The third combined receiving signal crc_signal_3 by combining the third uncombined receiving signal rcv_signal_3 and the fourth combined receiving signal c_signal_4 by combining the third uncombined receiving signal rcv_signal_2 and the fourth uncombined receiving signal rcv_signal_4. And combining the third uncombined reception signal rcv_signal_3 and the fourth uncombined reception signal rcv_signal_4 to combine the fifth combined reception signal c_signal_5, the first uncombined reception signal rcv_signal_1 and the fourth uncombined reception signal rcv_signal_4. ) Are combined to generate sixth combined received signals c_signal_6, respectively. The. The combined received signal c_signal and the uncoupled received signal rcv_signal received through the antenna are thus input to the relay signal selector 230.

According to the embodiment of FIG. 5, a total of 10 received signals of four uncombined received signals rcv_signal and six combined received signals c_signal may be generated through only four antennas. That is, the probability of selecting a non-oscillating signal is increased by generating a plurality of received signals of more than the number of antennas with a small number of antennas through the reception signal combiner 220. In addition, even when a signal received as an oscillation signal is combined, the combined reception signal c_signal may become a non-oscillation signal due to mutual cancellation, thereby increasing the possibility of selecting a non-oscillation signal.

On the other hand, the combined reception signal (c_signal) has the disadvantage that the intercell interference and intracell interference increases compared to the uncombined reception signal (rcv_signal), but because the signal from the base station is weak in a wireless environment requiring a repeater base station The intercell interference of is negligible. Therefore, intercell interference and intracell interference of the combined received signal c_signal may be ignored.

Although FIG. 5 illustrates a case where a combined reception signal (c_signal) is generated by combining two uncombined reception signals (rcv_signal), the combined reception signal by combining three or more uncombined reception signals (rcv_signal) according to a design. By generating (c_signal), the number of combined reception signals (c_signal) can be further increased.

6 illustrates a relay signal selector 230 according to an embodiment of the present invention. The relay signal selector 230 selects at least one or more of the non-oscillated signals among the plurality of non-combined reception signals and the plurality of combined reception signals to generate a relay signal.

In the method of selecting the non-oscillating signal, first, the signal size comparison unit 231 determines whether the magnitude of the received signal falls within a range of a predetermined upper limit value and a predetermined lower limit value. If the magnitude of the received signal is greater than or equal to the upper limit, it is determined as an oscillation signal. If the magnitude of the received signal is less than or equal to the lower limit, it is determined to be a weak signal of poor reception quality and is not selected as a relay signal. Next, the derivative comparison unit 232 selects a reception signal whose derivative value is within a predetermined threshold as a relay signal. When the derivative value is greater than or equal to the threshold value, the derivative value comparison unit 232 determines that the oscillation signal is a sudden change signal and selects the relay signal as a relay signal. It doesn't work.

At this time, the upper limit value, the lower limit value and the threshold value of the received signal derivative may be appropriately selected according to the frequency environment and the wireless environment used by the repeater.

On the other hand, when there are a large number of received signals satisfying the above conditions, first, the uncoupled received signal (rcv_signal) is selected as the relay signal from the combined received signal (c_signal) among the signals satisfying the upper limit value, the lower limit value, and the threshold value. It is desirable to further minimize the effects of intracell interference.

In addition, the relay signal selector 230 selects one or more received signals as a selection signal as shown in FIG. 6, but delays at least one chip of each of the selection signals to synthesize the relay signal by synthesizing them, thereby generating a time diver. It is desirable to improve the reception sensitivity of the relay signal at the receiving end having the rake receiver using the city. For example, the relay signal selector 230 selects three received signals, but the first selection signal does not pass through a zero chip delay, that is, a delay, and the second selection signal is one chip delay through the first delay unit 233. In addition, the third selection signal is preferably delayed by two chips through the second delay unit 234 and combined through the signal combiner 236 to generate a relay signal. In this embodiment, the intercell interference and the intracell interference may be increased by combining signals, but as described above, the influence of the interference may be ignored in a wireless environment requiring a repeater.

The relay signal selected by the relay signal selector 230 is amplified by the power amplifier 280 and transmitted through the transmit antenna unit 290. In this case, although the transmitting antenna unit 290 may be configured as a single antenna, it is more preferable that the transmitting antenna unit 290 is composed of a plurality of transmitting antennas 291, 292, 293 spaced apart from each other as shown in FIG. . More preferably, as shown in FIG. 7, the at least one transmitting antenna 292 and 293 may use the delays 294 and 295 to delay and transmit the relay signal by more than one chip.

According to the wireless repeater 200 of the present invention described above, since the non-oscillating signal is selected and relayed from the plurality of received signals through signal combination, the repeater 200 by the echo signal without a complicated and expensive digital signal processing unit is configured. Provides the effect of preventing rashes. On the other hand, when it is necessary to minimize the effects of the echo signal in addition to the reception signal combiner 220 and the relay signal selector 230 of the present invention, the conventional digital signal processor for digitally converting the relay signal to remove the echo signal ( It is preferable to further include 150).

8 illustrates a wireless relay method according to an embodiment of the present invention. First, a first step S100 of receiving a plurality of uncombined reception signals rcv_signal through a plurality of reception antennas R1, R2, R3, and R4 is performed.

Next, the reception signal combiner 220 performs a second step S200 of generating a plurality of combined reception signals c_signal by combining at least two of the plurality of uncombined reception signals rcv_signal.

Next, the relay signal selector 230 selects at least one of the non-oscillated signals among the plurality of uncombined reception signals rcv_signal and the plurality of combined reception signals c_signal to generate a relay signal. Step S300 is performed. At this time, the third step (S300) is that the size of the received signal is in the range of the predetermined upper limit and the predetermined lower limit (S310), so that the received signal whose derivative value is within the set threshold (S320) as a relay signal (S320) Can be configured. In this case, when there are several signals satisfying the upper limit value, the lower limit value, and the threshold value, it is preferable to first select the uncoupled reception signal rcv_signal as the relay signal.

On the other hand, in order to improve the time diversity at the receiving end, the third step S300 selects a plurality of received signals as a selection signal, but delays at least one chip of each of the selection signals to generate a relay signal by combining them. It is more preferable to (S330).

Finally, the power amplifier 280 amplifies the relay signal and the transmit antenna unit 290 performs a fourth step (S400) for transmitting it through the transmit antenna. In this case, in order to improve spatial diversity at the receiving end, a relay signal may be transmitted through a plurality of transmit antennas, and in order to improve time diversity, at least one transmit antenna delays the relay signal by one chip or more and transmits the delayed signal. It is more preferable to do.

On the other hand, if it is necessary to minimize the effect of the echo signal after the third step (S300) after the digital conversion of the relay signal to remove the effect of the echo signal through the conventional digital signal processing to remove the echo signal It may further include.

As described above, the wireless repeater and the wireless relay method according to the present invention include a plurality of non-combined reception signals received from a plurality of reception antennas and a plurality of combined reception signals combining signals received from a plurality of antennas. It does not have an expensive digital signal processor to remove the echo signal by selecting and relaying the -oscillation signal, thus providing the effect of removing the echo signal component with a simple structure and low cost.

In the wireless repeater and the wireless relay method according to an embodiment of the present invention, by generating a combined received signal using the uncoupled received signal received from each receive antenna, a plurality of received antennas or more receive signals are generated to generate a small number of multi-antennas. It provides the effect that can maximize the reception possibility of non-oscillation signal.

The wireless repeater and the wireless relay method according to another embodiment of the present invention provide an effect of easily determining the non-oscillation signal through the magnitude and derivative of each received signal.

In a wireless repeater and a wireless relay method according to another embodiment of the present invention, a plurality of non-oscillating signals are selected as a selection signal, and some of the selection signals are delayed by delaying at least one chip or more to improve time diversity and rake. A mobile station having a receiver or a base station provides an effect of increasing reception quality.

Lastly, the wireless repeater and the wireless relay method according to another embodiment of the present invention provide an effect of improving spatial diversity by improving relay diversity by transmitting relay signals through a plurality of transmitting antennas.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, those skilled in the art will be able to make various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the scope of the claims You will have to look.

Claims (18)

A receiving antenna unit comprising N antennas spaced apart from each other to receive N uncoupled reception signals; A received signal combiner configured to generate M combined received signals by combining at least two signals among the uncombined received signals; And And a relay signal selector configured to generate a relay signal by selecting at least one non-oscillation reception signal among the N non-combined reception signals and the M combined reception signals. The method of claim 1, wherein the relay signal selector, The signal is selected from among the N uncoupled received signals and the M combined received signals, wherein the signal size is within a range of a predetermined upper limit and a predetermined lower limit, and a signal whose derivative value is within a predetermined threshold is selected as the relay signal. Wireless repeater. The method of claim 2, wherein the relay signal selector, And a non-coupled received signal among the signals satisfying the upper limit value, the lower limit value, and the threshold value is selected as the relay signal. The method of claim 1, wherein the relay signal selector, Selecting K signals from among the N uncoupled received signals and the M combined received signals as a selection signal, wherein some of the selection signals are delayed by at least one chip or more, and then synthesized to generate the relay signal. Wireless repeater. The method of claim 4, wherein the relay signal selector Three signals from among the N uncoupled reception signals and the M combined reception signals are selected as a first selection signal, a second selection signal, and a third selection signal, respectively, wherein the first selection signal has a zero chip delay and the first selection signal. And a second selection signal having one chip delay, and the third selection signal having two chip delays, combining the two selection signals to generate a relay signal. The method of claim 1, wherein the wireless repeater, And a transmission antenna unit comprising P transmission antennas spaced apart from each other to transmit the relay signal. The method of claim 6, wherein the transmitting antenna unit, And at least one transmitting antenna transmits the delayed signal after delaying the relay signal by at least one chip. The method of claim 1, wherein the wireless repeater, And a digital signal processor for digitally converting the relay signal to remove an echo signal. Receive a first receiving antenna for receiving the first uncombined receiving signal, a second receiving antenna for receiving the second uncombined receiving signal, a third receiving antenna for receiving the third uncombined receiving signal, and a fourth uncombined receiving signal. A receiving antenna unit configured of a fourth receiving antenna;  Combining the first uncombined reception signal with the second uncombined reception signal to combine a first combined reception signal, the first uncombined reception signal and the third uncombined reception signal, and a second combined reception signal; A second combined received signal and the third uncoupled received signal are combined to combine a third combined received signal, the second uncoupled received signal and the fourth non-coupled received signal, and a fourth combined received signal and the third non-coupled received signal; A combination of a combined received signal and the fourth uncombined received signal to combine a fifth combined received signal, the first uncombined received signal and the fourth uncombined received signal to generate a sixth combined received signal, respectively; part; And A relay signal selector configured to generate a relay signal by selecting at least one of the first non-combined reception signal and the fourth non-combination reception signal and the first combined reception signal or the sixth combined reception signal and the non-oscillated reception signal; Wireless repeater comprising a. The method of claim 9, wherein the relay signal selector, A first selection signal, a second selection signal, and three reception signals that are not oscillated among the first uncombined reception signal through the fourth uncombined reception signal and the first combined reception signal through the sixth combined reception signal; The third selection signal is selected so that the first selection signal is 0 chip delay, the second selection signal is 1 chip delay, and the third selection signal is delayed 2 chips to combine the selection signals to generate the relay signal. Wireless repeater characterized. The method of claim 9, wherein the wireless repeater, And a transmitting antenna unit comprising two transmitting antennas, wherein each of the transmitting antennas transmits the relay signal. A first step of receiving a plurality of uncoupled received signals through a plurality of receive antennas; A second step of generating a plurality of combined reception signals by combining at least two of the plurality of uncombined reception signals;  A third step of generating a relay signal by selecting at least one non-oscillating reception signal among a plurality of non-combined reception signals and a plurality of combined reception signals; And And a fourth step of amplifying the relay signal and transmitting the same through the transmitting antenna. The method of claim 12, wherein the third step, Among the plurality of non-combined reception signals and the plurality of combined reception signals, a signal whose magnitude is within a range of a predetermined upper limit value and a predetermined lower limit value and whose derivative value is within a predetermined threshold value is selected as a relay signal. Wireless relay method. The method of claim 13, wherein the third step, And a non-coupling reception signal among the signals satisfying the upper limit value, the lower limit value, and the threshold value is selected as a relay signal. The method of claim 12, wherein the third step, And selecting a plurality of signals as a selection signal from among the plurality of non-combined reception signals and the plurality of combined reception signals, wherein some of the selection signals are delayed by at least one chip or more, and then, the relay signals are synthesized to generate the relay signal. Wireless relay method. The method of claim 12, wherein the fourth step, Wireless relay method, characterized in that for transmitting the relay signal through a plurality of transmit antennas. The method of claim 16, wherein the fourth step, The at least one transmitting antenna is a wireless relay method, characterized in that for transmitting after delaying the relay signal by more than one chip. The method of claim 12, wherein after the third step And digitally converting the relay signal to remove an echo signal through digital signal processing.

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