JP2018530972A - Signal channel correction compensation method and apparatus, and system - Google Patents

Abstract

Embodiments described herein relate generally to wireless communication technology, and more particularly, to a signal channel correction compensation method and apparatus and system. This method is a step of receiving each received signal from the correction reference channel of the wireless remote unit RRU by the baseband unit BBU, wherein each received signal has transmitted a transmission correction reference signal to each transmission channel of the RRU. A signal that is output from each transmission channel later, a step of calculating a channel delay of each transmission channel according to each received signal by the BBU, and a transmission channel corresponding to the minimum channel delay are transmitted by the BBU A step of calculating a compensation coefficient of each transmission channel using as a reference channel, and a step of performing compensation compensation for each transmission channel according to the compensation coefficient of each transmission channel by a BBU; Is a large positive integer, and the amount of received signals is equal to the amount of transmission channels. According to this signal channel correction compensation method, apparatus, and system, it is possible to effectively reduce intersymbol interference with respect to a received signal.

Description

  Embodiments described herein relate generally to wireless communication technology, and more particularly, to a signal channel correction compensation method and apparatus and system.

  In a wireless communication system, various data signals are transmitted and received using an antenna system. As an example, an antenna system used for a MIMO (Multiple-Input-Multiple-Output, multiple-input multiple-output system) transmission system in an LTE (Long Term Evolution) system is used. FIG. 1 shows a schematic structural diagram of a prior art antenna system. From FIG. 1, the main structure of the antenna system includes antenna 1, RRU2 (Radio Remote Unit), and BBU3 (Base Band Unit), and RRU2 has multiple signal channels. It can be seen that each signal channel includes a transmission channel and a reception channel. In the process of transmitting a signal with the antenna system described above, each transmission channel needs to satisfy a specific transmission request in order to guarantee a relatively high signal transmission quality. For example, the transmission channel delay and phase are aligned at the air interface. In another example, the ratio of the channel response of the signal channel to the receive channel is equal to the channel response of the transmit channel.

  In an actual antenna system, jitter occurs in the intermediate frequency part of the transceiver channel, and the responses of the analog components of the radio frequency do not match, so it is difficult for each transmission channel to satisfy the above transmission request. A correction reference channel is typically placed in RRU2 so that each transmission channel can satisfy the transmission request, and a compensation factor for each transmission channel is calculated using a correction reference channel and a signal compensation algorithm, then Correction compensation is performed for each transmission channel according to the compensation coefficient of each transmission channel.

  After performing compensation compensation on the transmit channel using existing channel correction methods, the data segment received from the receive channel may contain symbol sampling points for the next data segment, resulting in ISI ( Inter-Symbol-Interference).

  Embodiments of the present invention provide a signal channel correction compensation method and apparatus and system for effectively reducing intersymbol interference on a received signal.

According to a first aspect, an embodiment of the present invention is a signal channel correction compensation method,
Receiving each received signal from the correction reference channel of the wireless remote unit RRU by the baseband unit BBU, wherein each received signal is transmitted after the BBU transmits a transmission correction reference signal to each transmission channel of the RRU. Steps corresponding to signals output from
Calculating a channel delay of each transmission channel according to each received signal by the BBU;
Calculating a compensation coefficient for each transmission channel using the transmission channel corresponding to the minimum channel delay as a transmission reference channel by the BBU;
Performing correction compensation on each transmission channel according to the compensation coefficient of each transmission channel by the BBU, and
The amount of received signal is a positive integer greater than 1, and the amount of received signal is equal to the amount of transmission channel;
A signal channel correction compensation method is provided.

Optionally, calculating the channel delay of each transmission channel according to each received signal by the BBU,
Calculating a frequency domain channel response of each transmission channel according to each received signal received by the BBU;
Calculating the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel by the BBU.

Optionally, calculating the frequency domain channel response of each transmission channel according to each received signal received by the BBU comprises:
By BBU, the formula

Calculating the frequency domain channel response of each transmission channel according to
Where s _{tx, i} (k) indicates the correction reference signal transmitted by the BBU to the i th transmission channel of the _RRU, and r _{rxc, i} (k) is the i th reception received by the correction reference channel. Indicates a received signal corresponding to a transmission channel, k indicates a sequence number of a frequency domain subcarrier, a range of values of k is 0 to N-1, N is a total amount of frequency domain subcarriers, The range of the value of i is from 0 to a number obtained by subtracting 1 from the total amount of RRU transmission channels, i and k are both integers greater than or equal to 0, and N is a positive integer.

Optionally, the BBU calculating a compensation factor for each transmission channel using the transmission channel corresponding to the minimum channel delay as a transmission reference channel,
Calculating an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel by the BBU;
Calculating a compensation coefficient for each transmission channel using the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay as a reference by the BBU.

Optionally, calculating by BBU an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel comprises:
Obtaining an initial correction compensation factor for each transmission channel by calculating the reciprocal of the frequency domain channel response of each transmission channel by the BBU.

Optionally, the BBU calculating a compensation factor for each transmission channel using the initial correction compensation factor for the transmission channel corresponding to the minimum channel delay as a reference,
The BBU includes obtaining a compensation coefficient for each transmission channel by dividing the initial correction compensation coefficient for each transmission channel by the initial correction compensation coefficient for the transmission channel corresponding to the minimum channel delay.

Optionally, the BBU is connected to multiple RRUs,
The step of receiving each received signal from the correction reference channel of the wireless remote unit RRU by the baseband unit BBU is as follows:
A step of receiving each received signal from each correction reference channel of the RRU by the BBU, wherein each received signal is transmitted to each of the plurality of RRUs after the BBU transmits a transmission correction reference signal to each transmission channel of the plurality of RRUs A signal that is output from the transmission channel correspondingly.

According to a second aspect, an embodiment of the present invention is a signal channel correction compensation apparatus, which is arranged in a baseband unit BBU,
A receiving unit that receives each received signal from the correction reference channel of the wireless remote unit RRU, wherein each received signal is transmitted from each transmission channel after the BBU transmits a transmission correction reference signal to each transmission channel of the RRU. A receiving unit configured to receive, the correspondingly output signal, the amount of the received signal is a positive integer greater than 1, and the amount of the received signal is equal to the amount of the transmission channel;
A channel delay calculation unit configured to calculate a channel delay of each transmission channel according to each received signal;
A compensation factor calculation unit configured to calculate a compensation factor for each transmission channel using the transmission channel corresponding to the minimum channel delay as a transmission reference channel;
There is provided a signal channel correction compensation apparatus including a correction compensation unit configured to perform correction compensation on each transmission channel according to a compensation coefficient of each transmission channel.

  Optionally, the channel delay calculation unit specifically calculates the frequency domain channel response of each transmission channel according to each received signal received, and specifically calculates the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel. Composed.

  Optionally, the channel delay calculation unit has the formula

Is specifically configured to calculate the frequency domain channel response of each transmission channel according to where s _{tx, i} (k) denotes a corrected reference signal transmitted by the BBU to the i th transmission channel of the _RRU , and r _{rxc , I} (k) indicates the received signal corresponding to the i-th transmission channel received by the correction reference channel, k indicates the sequence number of the frequency domain subcarrier, and the range of values of k is from 0 to N−1, where N is the total amount of frequency domain subcarriers, the range of values of i is from 0 to the number obtained by subtracting 1 from the total amount of RRU transmission channels, and i and k are Both are integers greater than or equal to 0, and N is a positive integer.

Optionally, the compensation factor calculation unit is specifically configured to calculate an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel;
The BBU calculates the compensation coefficient of each transmission channel using the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay as a reference.

  Optionally, the compensation factor calculation unit is specifically configured to obtain an initial correction compensation factor for each transmission channel by calculating the inverse of the frequency domain channel response of each transmission channel.

  Optionally, the compensation factor calculation unit specifically obtains the compensation factor for each transmission channel by dividing the initial correction compensation factor for each transmission channel by the initial correction compensation factor for the transmission channel corresponding to the minimum channel delay. Composed.

Optionally, the BBU is connected to multiple RRUs,
The reception unit receives each reception signal from the correction reference channel of each RRU, and each reception signal transmits each transmission of the plurality of RRUs after the BBU transmits a transmission correction reference signal to each transmission channel of the plurality of RRUs. It is specifically configured to receive, which is a signal output correspondingly from the channel.

According to a third aspect, one embodiment of the present invention is an antenna system including an antenna, a radio remote unit RRU, and a baseband unit BBU,
The RRU includes a correction reference channel and a plurality of transmission channels, the correction reference channel is connected to both the antenna and the BBU, and the plurality of transmission channels are connected in parallel between the antenna and the BBU;
The BBU is configured to perform correction compensation for each transmission channel of the RRU.
The BBU receives each received signal from the RRU correction reference channel, and each received signal is output correspondingly from each transmission channel after the BBU transmits the transmission correction reference signal to each transmission channel of the RRU. Receiving a signal,
The BBU calculates the channel delay of each transmission channel according to each received signal;
The BBU calculates a compensation coefficient for each transmission channel using the transmission channel corresponding to the minimum channel delay as a transmission reference channel;
The BBU performs correction compensation for each transmission channel according to the compensation coefficient of each transmission channel, and
The amount of received signal is a positive integer greater than 1, and the amount of received signal is equal to the amount of transmission channel;
An antenna system is provided.

  Optionally, the BBU is specifically configured to calculate the frequency domain channel response of each transmission channel according to each received signal received and to calculate the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel. .

  Optionally, the BBU is an expression

Specifically configured to calculate the frequency domain channel response of each transmission channel according to
Where s _{tx, i} (k) indicates the correction reference signal transmitted by the BBU to the i th transmission channel of the _RRU, and r _{rxc, i} (k) is the i th reception received by the correction reference channel. Indicates a received signal corresponding to a transmission channel, k indicates a sequence number of a frequency domain subcarrier, a range of values of k is 0 to N-1, N is a total amount of frequency domain subcarriers, The range of the value of i is from 0 to a number obtained by subtracting 1 from the total amount of RRU transmission channels, i and k are both integers greater than or equal to 0, and N is a positive integer.

  Optionally, the BBU is specifically configured to calculate an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel, and further, an initial correction compensation factor for the transmission channel corresponding to the minimum channel delay. It is specifically configured to calculate a compensation factor for each transmission channel using as a reference.

  Optionally, the BBU is specifically configured to obtain an initial correction compensation factor for each transmission channel by calculating the reciprocal of the frequency domain channel response of each transmission channel.

  Optionally, the BBU is specifically configured to obtain a compensation factor for each transmission channel by dividing the initial correction compensation factor for each transmission channel by the initial correction compensation factor for the transmission channel corresponding to the minimum channel delay. .

Optionally, the BBU is connected to multiple RRUs,
The BBU receives each received signal from the correction reference channel of each RRU, and each received signal transmits each transmission channel of the plurality of RRUs after the BBU transmits a transmission correction reference signal to each transmission channel of the plurality of RRUs. Is specifically configured to receive a signal that is output correspondingly.

According to a fourth aspect, an embodiment of the present invention is a signal channel correction compensation device, wherein the device is arranged in an antenna system,
A communication interface, a memory, a processor, and a communication bus, wherein the communication interface, the memory, and the processor communicate with each other using the communication bus;
When the memory is configured to store the program, the processor is configured to execute the program stored in the memory, and the topology learning device of the Openflow network traversing the traditional Internet Protocol IP network operates, the processor Run the program and the program will
Receiving each received signal from the correction reference channel of the wireless remote unit RRU, each received signal being output correspondingly from each transmission channel after the device has transmitted the transmission correction reference signal to each transmission channel of the RRU A step signal,
Calculating a channel delay of each transmission channel according to each received signal;
Calculating a compensation factor for each transmission channel using the transmission channel corresponding to the minimum channel delay as a transmission reference channel;
Performing correction compensation for each transmission channel according to the compensation coefficient of each transmission channel, and
The amount of received signal is a positive integer greater than 1, and the amount of received signal is equal to the amount of transmission channel;
A signal channel correction compensation device is provided.

  According to the signal channel correction compensation method, apparatus, device, and system of the embodiments of the present invention, when obtaining the compensation coefficient of the signal channel, the transmission channel corresponding to the minimum channel delay is used as the transmission reference channel. Thus, it is possible to effectively prevent the current received segment from including the symbol sampling point of the next segment, and ISI that occurs in this case can be avoided.

  To describe the technical solutions of the embodiments of the present invention or the prior art more clearly, the following briefly describes the accompanying drawings required for describing the embodiments or the prior art. Apparently, the accompanying drawings in the following description show some embodiments of the present invention, and those skilled in the art can further obtain other drawings from these accompanying drawings without creative efforts.

The schematic structure figure of the antenna system in a prior art is shown. Fig. 4 shows another schematic structural diagram of an antenna system. Fig. 6 shows yet another schematic structural diagram of the antenna system. Fig. 6 shows yet another schematic structural diagram of the antenna system. Fig. 4 shows a schematic effect diagram of signal channel correction compensation; Fig. 4 shows a schematic effect diagram of signal channel correction compensation; 5 shows a flowchart of a signal channel correction compensation method according to an embodiment of the present invention. 6 shows another flowchart of a signal channel correction compensation method according to an embodiment of the present invention. 1 shows a schematic structural diagram in which a single cell includes multiple RRUs. 6 shows yet another flowchart of a signal channel correction compensation method according to an embodiment of the present invention. 1 shows a schematic structural diagram of a signal channel correction compensation apparatus according to an embodiment of the present invention. FIG. 1 shows a schematic structural diagram of a signal channel correction compensation device according to an embodiment of the present invention. FIG.

  In order to clarify the purpose, technical solutions, and advantages of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clarified below with reference to the accompanying drawings of the embodiments of the present invention. And fully explain. Apparently, the described embodiments are a part of the embodiments of the present invention and not all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

  In the embodiment of the present invention, in order to describe the signal channel correction method of the embodiment of the present invention in detail, an antenna system used for the MIMO transmission scheme in the LTE system is used as an example.

  Based on the structure of the antenna system of FIG. 1, FIG. 2 shows another schematic structural diagram of the antenna system.

  From FIG. 2, it can be seen that the main structure of the antenna system includes the antenna 1, the RRU 2, and the BBU 3. RRU2 includes a plurality of signal channels, and each signal channel includes a reception channel and a transmission channel. The RRU2 of the antenna system shown in FIG. 2 includes four signal channels. For example, the 0th signal channel includes a transmission channel and a reception channel. The transmission channel includes the transmission circuit TX0, which is connected to the transceiver interface TRX0 of BBU3 using CPRI (Common Public Radio Interface) and connected to antenna 1 using the channel combination module Is done. The reception channel includes a reception circuit RX0. The reception circuit RX0 is connected to the transceiver interface TRX0 of the BBU3 using CPRI, and is connected to the antenna 1 using a channel combination module.

  In FIG. 2, the channel combination module is an electronic device for separating a reception channel and a transmission channel, and is in particular a duplexer, a switch circuit, or a circulator.

  The connection structure of another signal channel included in RRU2 is the same as the connection structure of the 0th signal channel, and detailed description thereof is omitted.

  The LTE system uses the antenna system shown in Figure 2 to perform MIMO transmission in two ways: BF (Beamforming) and CL-MIMO (Closed-Loop MIMO). To do. Transmission is performed by the BF transmission method and the CL-MIMO transmission method by weighting on the base station side, whereby the signals of the plurality of transmission antennas 1 are coherently superimposed when the signals are received. In this way, array gain is obtained, and the user's SINR (Signal to Interference plus Noise Ratio) increases.

  In either the BF transmission technique or the CL-MIMO transmission technique, the transmission channel of the antenna system needs to satisfy specific transmission conditions in order to obtain a relatively high transmission quality.

For example, in CL-MIMO transmission technology, it is necessary to ensure that the delay and phase of the transmission channel are aligned at the air interface, which is expressed by the following equation.
h _{tx, 0} (k) = h _{tx, 1} (k) = L = h _{tx, 3} (k)

In the above equation, h _{tx, 0} (k) to h _{tx, 3} (k) indicate the frequency domain channel responses of transmission channel 0 to transmission channel 3, respectively, and k indicates the sequence number of the frequency domain subcarrier. , K ranges from 0 to Nfft−1, where Nfft is the total amount of frequency domain subcarriers.

Alternatively, in CL-MIMO transmission technology, the response of the transmission channel is matched by using delay or frequency domain compensation, which is expressed as:
β _{tx, 0} × h _{tx, 0} (k) = β _{tx, 1} × h _{tx, 1} (k) = L = β _{tx, 3} × h _{tx, 3} (k)
_{However, β tx, 0 ~β tx,} 3 shows the respective correction compensation coefficient of the transmission channel 0 transmit channel 3.

  In another example, in the BF transmission technique, the ratio of the channel response of the receive channel to the channel response of the transmit channel is equal, ie, the formula

Is established. Where h _{rx, 0} (k) to h _{rx, 3} (k) indicate the frequency domain channel responses of reception channel 0 to reception channel 3, respectively, k indicates the sequence number of the frequency domain subcarrier, and k The range of values is 0 to Nfft−1, where Nfft is the total amount of frequency domain subcarriers.

  Alternatively, in the BF transmission technique, the response of the transmission channel is matched by using delay or frequency domain compensation, ie, the equation

Is established. _{However, β tx, 0 ~β tx,} 3 each represent correction compensation coefficient of the transmission channel 0 transmit channel _{3, β rx, 0 ~β rx} , 3 is modified compensation of each receive channel 0 receive channel 3 Indicates the coefficient.

  First-in first-out (FIFO) jitter occurs in the intermediate frequency portion of the transceiver channel, and the response of the analog component of the radio frequency does not match, so the channel may be aligned if frequency domain or time domain compensation is not performed Can not. Therefore, it is necessary to obtain a correction compensation coefficient using a channel compensation algorithm and hardware design.

  The method for obtaining a correction compensation factor according to an embodiment of the present invention includes designing an additional correction reference channel 4.

  FIG. 3 shows yet another schematic structural diagram of the antenna system. In order to obtain a correction compensation factor for the signal channel, a coupling circuit 5 and a correction reference channel 4 are added to the structure of the antenna system. In particular, the coupling circuit 5 is arranged on the antenna, which is an external correction method. In this correction method, the transmission channel includes an RRU2 TX (transmitter) circuit and a feeder 6, and the reception channel includes an RRU2 RX (Receiver) circuit and a feeder 6. For example, the 0th transmission channel includes the transmission circuit TX0 and the feeder 6, and the 0th reception channel includes the reception circuit RX0 and the feeder 6. In this aspect, the TX circuit and feeder correction can be completed by arranging the coupling circuit 5 in the antenna.

  FIG. 4 shows yet another schematic structural diagram of the antenna system. FIG. 4 differs from FIG. 3 in that the coupling circuit 5 added to the antenna system is arranged in the RRU in this embodiment, which is an internal correction method. In this correction method, the transmission channel includes an RRU2 TX circuit, and the reception channel includes an RRU2 RX circuit. For example, the 0th transmission channel includes the transmission circuit TX0, and the 0th reception channel includes the reception circuit RX0. In this embodiment, the coupling circuit is placed in the RRU, and the correction of the TX circuit is completed by transmitting a signal from the outbound port (or internal) of the RRU to the coupling circuit 5. Length consistency between external feeders can only be ensured by structural constraints.

  3 and 4, the coupling circuit 5 may be a circuit including a power splitter / combiner. The coupling circuit 5 in FIG. 4 is connected to the output end of each transmission channel using a directional coupler.

  3 and 4, the correction reference channel 4 includes a transmission circuit TXc and a reception circuit RXc. The BBU 3 transmits the reception correction reference signal to the transmission circuit TXc. After the signal passes through the coupling circuit 5 and the antenna 1, the BBU 3 receives a feedback signal from each reception channel of the RRU 2, and obtains a compensation coefficient for each reception channel according to the feedback signal.

  The reception circuit RXc of the correction reference channel 4 is configured to receive the signal output from the combining circuit 5 and output the received signal to the BBU 3 so that each transmission channel of the RRU can be corrected according to the signal received by the BBU 3 . Hereinafter, the process of correcting the transmission channel will be described in detail, but detailed description thereof will be omitted.

  In the two antenna systems shown in FIG. 3 and FIG. 4, the defined ranges of the transmission channel and the reception channel are different, but the method for performing signal channel correction provided in the embodiment of the present invention is the same. is there. As an example for explaining the signal channel correction compensation method of the embodiment of the present invention in detail, the antenna system shown in FIG. 3 is used.

  When performing transmission channel correction using the antenna system shown in FIG. 3, the BBU 3 controls the start of correction and transmits a transmission correction reference signal to each transmission channel. In FIG. 3, BBU3 uses the transceiver interface TRX0 to transmit the transmission correction reference signal to the transmission circuit TX0, uses the transceiver interface TRX1 to transmit the transmission correction reference signal to the transmission circuit TX1, and uses the transceiver interface TRX2. Then, the transmission correction reference signal is transmitted to the transmission circuit TX2, and the transmission correction reference signal is transmitted to the transmission circuit TX3 using the transceiver interface TRX3. In this method, the BBU 3 can transmit the transmission correction reference signal to the transmission channel by frequency division, time division, space division, or the like.

The transmission correction reference signals transmitted to the four transmission channels by the BBU 3 are collected using the combining circuit 5 and then transmitted to the correction reference channel 4. The BBU 3 receives reception information corresponding to the transmission channel on a one-to-one basis from the correction reference channel. It is _{assumed that} the signals of the reception channel are r _{rxc, 0} (k), r _{rxc, 1} (k), r _{rxc, 2} (k), and r _{rxc, 3} (k). The frequency domain channel response of each transmission channel can be obtained by least square channel estimation, and the equation for LS channel estimation is

It is. However,

Is the estimated frequency domain channel response of the i th transmission channel, r _{rxc, i} (k) is the i th received signal received using the corrected reference channel 4, and _{st x , i} (k ) Is the i-th correction reference signal transmitted by the BBU 3, and the value of i is 0 to 3 in the antenna system shown in FIG.

  The above equation for LS channel estimation is

It is simplified as follows. Here, h _rxc (k) is the channel response of the reception channel of the correction reference channel, and h _{tx, i} (k) is the channel response of the i-th transmission channel.

An initial correction compensation coefficient can be obtained by calculating the reciprocal of each of the above. That is, the initial correction compensation coefficient of the i-th transmission channel is given by the equation

Calculated according to

In order to improve the accuracy of the obtained initial correction compensation coefficient before calculating the initial correction compensation coefficient using

Noise reduction processing may be performed on the image.

  Furthermore, in order to avoid the additional delay caused by the correction reference channel 4, after acquiring the initial correction coefficient, a relative correction is performed on the acquired correction compensation coefficient using the transmission channel as a reference, Relative correction is performed using channel 0 as a reference. That is,

It is.

  Since the delay difference between the channels of RRU2 is relatively small, it is not a big problem to use channel 0 as a reference. However, special consideration is required for a specific RRU2 or a single cell containing two RRU2.

  5A and 5B show schematic effect diagrams of signal channel correction compensation. From the figure, it can be seen that when channel 0 is used as a reference, the correction compensation scheme used by channel 0 includes reciprocal compensation, minimum delay compensation, and maximum delay compensation. When performing relative correction using the channel with the longest delay as a reference, the sampling point of the next OFDM symbol is received in the current OFDM (Orthogonal Frequency Division Multiplexing) data at the receiving end, and the ISI is Occur.

  In order to solve the above problem, an embodiment of the present invention provides a signal channel correction compensation method. In this method, when the compensation coefficient of the signal channel is obtained, the transmission channel corresponding to the minimum channel delay is used as the transmission reference channel, so that the current reception segment includes the symbol sampling point of the next segment. Can be prevented, and ISI that occurs in this case can be avoided.

  FIG. 6 shows a flowchart of a signal channel correction compensation method according to an embodiment of the present invention. The method is executed by the BBU and includes the following main processing steps.

  Step S11: The BBU receives each received signal from the RRU correction reference channel.

  Each received signal is a signal that is output correspondingly from each transmission channel after the BBU transmits a transmission correction reference signal to each transmission channel of the RRU.

  In particular, the amount of received signal is a positive integer greater than 1, and the amount of received signal is equal to the amount of transmission channel.

  In particular, the specific process by which the BBU receives each received signal from the RRU's corrected reference channel includes:

  (1) The BBU transmits a transmission correction reference signal to each transmission channel of the RRU.

  For example, in FIG. 3, the BBU 3 includes a transmission circuit TX0, a transmission circuit TX1,. . . And a transmission correction reference signal to each of the transmission circuits TX3.

  (2) The BBU receives a reception signal having a one-to-one correspondence with the transmission channel from the RRU correction reference channel.

  For example, in FIG. 3, the BBU 3 receives each reception signal from the reception circuit RXc of the correction reference channel.

  Step S12: The BBU calculates the channel delay of each transmission channel according to each received signal.

  Step S13: The BBU calculates a compensation coefficient for each transmission channel using the transmission channel corresponding to the minimum channel delay as the transmission reference channel.

  Step S14: The BBU performs correction compensation for each transmission channel according to the compensation coefficient of each transmission channel.

  Referring to FIGS. 5A and 5B, in this embodiment of the invention, the current received segment includes the symbol sampling point of the next segment by using the transmission channel corresponding to the minimum channel delay as the transmission reference channel. It can be seen that ISI can be effectively prevented, and ISI occurring in this case can be avoided.

  FIG. 7 shows another flowchart of a signal channel correction compensation method according to an embodiment of the present invention. The method is executed by the BBU and includes the following main processing steps.

  Step S21: The BBU transmits a transmission correction reference signal to each transmission channel of the RRU.

  Step S22: The BBU receives a reception signal having a one-to-one correspondence with the transmission channel from the RRU correction reference channel.

  Step S23: The BBU calculates a frequency domain channel response of each transmission channel according to the received reception signal.

The step of calculating the frequency domain channel response of each transmission channel according to the received signal received by the BBU is:
By BBU, the formula

Calculating the frequency domain channel response of each transmission channel according to: Where s _{tx, i} (k) indicates the correction reference signal transmitted by the BBU to the i th transmission channel of the _RRU, and r _{rxc, i} (k) is the i th reception received by the correction reference channel. Indicates a received signal corresponding to a transmission channel, k indicates a sequence number of a frequency domain subcarrier, a range of values of k is 0 to N-1, N is a total amount of frequency domain subcarriers, The range of the value of i is from 0 to a number obtained by subtracting 1 from the total amount of RRU transmission channels, i and k are both integers greater than or equal to 0, and N is a positive integer.

  This formula is

It is simplified as follows. Here, h _rxc (k) is the channel response of the reception channel of the correction reference channel, and h _{tx, i} (k) is the channel response of the i-th transmission channel.

  Step S24: The BBU calculates the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel.

  In this step, the channel delay of each transmission channel is calculated in the time domain according to the frequency domain channel response value.

  Step S25: The BBU calculates an initial correction compensation coefficient for each transmission channel according to the frequency domain channel response of each transmission channel.

  In particular, the BBU obtains an initial correction compensation factor for each transmission channel by calculating the reciprocal of the frequency domain channel response of each transmission channel.

  In this step, the BBU formula

To calculate the initial correction compensation factor of the i th transmission channel according to

Before calculating the initial correction compensation coefficient using BBU, in order to improve the accuracy of the initial correction compensation coefficient obtained

Noise reduction processing may be performed on the image.

  Step S26: The BBU calculates a compensation coefficient for each transmission channel using the initial correction compensation coefficient for the transmission channel corresponding to the minimum channel delay as a reference.

  The BBU obtains a compensation coefficient for each transmission channel by dividing the initial correction compensation coefficient for each transmission channel by the initial correction compensation coefficient for the transmission channel corresponding to the minimum channel delay.

  Step S27: The BBU performs correction compensation on each transmission channel according to the compensation coefficient of each transmission channel.

  The above-described method in Embodiment 1 and Embodiment 2 of the present invention can be applied to an antenna system including a single RRU in a single cell, or to an antenna system including a plurality of RRUs in a single cell. Can be applied. For example, as shown in FIG. 8, one antenna system may include two RRUs, and each RRU may include two signal channels.

  When a single cell includes a plurality of RRUs, each of the plurality of RRUs is connected to a BBU in this cell. When the BBU corrects the transmission channels of a plurality of RRUs, the BBU receives each received signal from the correction reference channel of each RRU. Each received signal is a signal output correspondingly from each transmission channel of the plurality of RRUs after the BBU transmits a transmission correction reference signal to each transmission channel of the plurality of RRUs.

  After receiving the reception signal output by each RRU, the BBU calculates a correction compensation coefficient for each transmission channel according to the method of Embodiment 1 or Embodiment 2. The method for calculating the correction compensation coefficient is the same as in the first or second embodiment, and a detailed description thereof is omitted.

  FIG. 9 shows still another flowchart of a signal channel correction compensation method according to an embodiment of the present invention. The method is executed by the BBU and includes the following main processing steps.

  Step S31: The RRU is activated. In this case, the channel response of the transmission channel and the reception channel of the RRU varies because the temperature and humidity of the channel change.

  Step S32: The BBU determines whether or not the RRU activation time exceeds X minutes.

  In consideration of fluctuations in the channel response of the RRU transmission channel and the reception channel, the BBU does not start channel correction until the channel response is stabilized. That is, the BBU determines whether the RRU activation time exceeds x minutes, and if the RRU activation time exceeds X minutes, it indicates that the channel response is stable and the BBU can perform channel correction. means.

  Step S33: The BBU triggers correction of the RRU transmission channel.

  The BBU transmits a transmission correction reference signal to a plurality of transmission channels. In particular, the transmission correction reference signal may be transmitted by a plurality of methods such as time division, frequency division, or code division. The transmission correction reference signal passes through the RRU and the antenna and is looped back from the combining circuit to the receiving channel of the correction reference channel (in some cases, the transmission correction reference signal does not pass through the antenna but the combining circuit in the RRU. Is directly looped back, but there is no difference in the processing procedure, and it will not be explained separately). The BBU performs LS channel estimation on the received signal acquired from the reception channel of the correction reference channel, and uses the LS channel estimation result to obtain the initial transmission correction coefficient for each transmission channel. The BBU performs LS channel estimation after performing operations such as noise reduction and filtering. The initial transmission correction factor is obtained by calculating the reciprocal of the channel estimation result.

  Step S34: The BBU acquires the channel delay of each transmission channel according to the acquired LS channel estimation value, selects the channel with the smallest channel delay as the transmission reference channel, and uses the initial transmission correction coefficient of the reference channel as the normalization coefficient Then, the relative correction processing is performed on the initial transmission correction coefficient, that is, all the initial transmission correction coefficients are divided by the initial transmission correction coefficient of the reference channel to obtain the second correction compensation coefficient.

  The method for calculating the initial correction compensation coefficient and the second correction compensation coefficient in step S33 and step S34 is the same as in the second embodiment, and detailed description thereof is omitted.

  Step S35: The BBU triggers correction of the RRU reception channel.

  The BBU transmits a reception correction reference signal to the transmission channel of the correction reference channel. The received correction reference signal passes through the RRU and the antenna and is looped back from the combining circuit to the RRU's multiple receiving channels (in some cases, the received correction reference signal does not pass through the antenna but the combining circuit in the RRU. Is directly looped back, but there is no difference in the processing procedure, and it will not be explained separately). The BBU performs LS channel estimation on the received signal acquired from the reception channel, and then the BBU calculates the initial reception correction coefficient of each reception channel using the LS channel estimation result of each reception channel of the RRU, In that case, the BBU optionally performs LS channel estimation after performing operations such as noise reduction and filtering on the received signal. The initial reception correction coefficient is obtained by calculating the reciprocal of the channel estimation result. (This step may not be performed on FDD systems)

  Step S36: The BBU selects channel 0 (random selection is possible) as a reception reference channel according to the obtained LS channel estimation value, uses the initial reception correction coefficient of the reception reference channel as a normalization coefficient, Relative correction processing is performed, that is, all initial reception correction coefficients are divided by the reference channel initial reception correction coefficients to obtain a second reception correction coefficient (this step may not be performed in an FDD system). .

  After the initial correction is completed, the channel with the smallest channel delay is used as a reference channel to perform relative correction, and as a result, ISI generated by correction compensation is avoided.

  FIG. 10 is a schematic structural diagram of a signal channel correction compensation apparatus according to an embodiment of the present invention. This apparatus is arranged in the baseband unit BBU, and includes a reception unit 41, a channel delay calculation unit 42, a compensation coefficient calculation unit 43, and a correction compensation unit 44.

  The reception unit 41 receives each reception signal from the correction reference channel of the wireless remote unit RRU, and each reception signal corresponds to each transmission channel after the BBU transmits a transmission correction reference signal to each transmission channel of the RRU. The received signal amount is a positive integer larger than 1, and the received signal amount is equal to the transmission channel amount.

  The channel delay calculation unit 42 is configured to calculate the channel delay of each transmission channel according to each received signal.

  The compensation coefficient calculation unit 43 is configured to calculate a compensation coefficient for each transmission channel using the transmission channel corresponding to the minimum channel delay as the transmission reference channel.

  The correction compensation unit 44 is configured to perform correction compensation for each transmission channel according to the compensation coefficient of each transmission channel.

  In the above embodiment, the channel delay calculation unit 42 calculates the frequency domain channel response of each transmission channel according to each received signal received, and calculates the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel. Especially configured.

  In the above embodiment, the channel delay calculation unit 42 has the formula

And is specifically configured to calculate a frequency domain channel response for each transmission channel. Where s _{tx, i} (k) indicates the correction reference signal transmitted by the BBU to the i th transmission channel of the _RRU, and r _{rxc, i} (k) is the i th reception received by the correction reference channel. Indicates a received signal corresponding to a transmission channel, k indicates a sequence number of a frequency domain subcarrier, a range of values of k is 0 to N-1, N is a total amount of frequency domain subcarriers, The range of the value of i is from 0 to a number obtained by subtracting 1 from the total amount of RRU transmission channels, i and k are both integers greater than or equal to 0, and N is a positive integer.

In the above embodiment, the compensation factor calculation unit 43 is specifically configured to calculate an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel,
The BBU calculates the compensation coefficient of each transmission channel using the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay as a reference.

  In the above embodiment, the compensation factor calculation unit 43 is specifically configured to obtain an initial correction compensation factor for each transmission channel by calculating the reciprocal of the frequency domain channel response of each transmission channel.

  In the above embodiment, the compensation coefficient calculation unit 43 obtains the compensation coefficient for each transmission channel by dividing the initial correction compensation coefficient for each transmission channel by the initial correction compensation coefficient for the transmission channel corresponding to the minimum channel delay. Especially configured.

In the above embodiment, the BBU is connected to a plurality of RRUs,
The receiving unit 41 receives each reception signal from the correction reference channel of each RRU, and each reception signal is transmitted to each transmission channel of the plurality of RRUs after the BBU transmits a transmission correction reference signal to each transmission channel of the plurality of RRUs. It is specifically configured to receive, which is a signal output correspondingly from the transmission channel.

  FIG. 3 shows a schematic structural diagram of an antenna system according to an embodiment of the present invention. The antenna system includes an antenna 1, an RRU 2, and a BBU 3.

  RRU2 includes a correction reference channel and a plurality of transmission channels. The correction reference channel is connected to both the antenna and BBU3, and the plurality of transmission channels are connected in parallel between the antenna and BBU3.

BBU3 is configured to perform compensation compensation for each transmission channel of RRU2, and this compensation compensation is
BBU3 receives each received signal from the RRU2 correction reference channel, and each received signal is output correspondingly from each transmission channel after the BBU3 transmits a transmission correction reference signal to each transmission channel of RRU2. Receiving a signal,
BBU3 calculates the channel delay of each transmission channel according to each received signal,
BBU3 calculates a compensation factor for each transmission channel using the transmission channel corresponding to the minimum channel delay as a transmission reference channel; and
BBU3 performs correction compensation for each transmission channel according to the compensation coefficient of each transmission channel. In this case, the amount of the received signal is a positive integer greater than 1, and the amount of the received signal is the amount of the transmission channel. Equal to the quantity.

  In the above embodiment, the BBU 3 is specifically configured to calculate the frequency domain channel response of each transmission channel according to each received signal received, and to calculate the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel. The

  In the above embodiment, BBU3 has the formula

And is specifically configured to calculate a frequency domain channel response for each transmission channel. Where s _{tx, i} (k) indicates the correction reference signal transmitted by the BBU3 to the i th transmission channel of _RRU2, and r _{rxc, i} (k) is the i th reception received by the correction reference channel. Indicates a received signal corresponding to a transmission channel, k indicates a sequence number of a frequency domain subcarrier, a range of values of k is 0 to N-1, N is a total amount of frequency domain subcarriers, The range of the value of i is from 0 to a number obtained by subtracting 1 from the total amount of RRU transmission channels, i and k are both integers greater than or equal to 0, and N is a positive integer.

  In the above embodiment, the BBU 3 is specifically configured to calculate the initial correction compensation coefficient of each transmission channel according to the frequency domain channel response of each transmission channel, and further, the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay Is specifically configured to calculate a compensation factor for each transmission channel.

  In the above embodiment, the BBU 3 is specifically configured to obtain an initial correction compensation factor for each transmission channel by calculating the reciprocal of the frequency domain channel response of each transmission channel.

  In the above embodiment, the BBU 3 is specifically configured to obtain the compensation coefficient of each transmission channel by dividing the initial correction compensation coefficient of each transmission channel by the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay. The

In the above embodiment, the BBU 3 is connected to a plurality of RRUs 2,
BBU3 receives each received signal from the correction reference channel of each RRU2, and each received signal transmits each transmission channel of the plurality of RRU2 after the BBU3 transmits a transmission correction reference signal to each of the transmission channels of the plurality of RRU2. Is specifically configured to receive a signal that is output correspondingly.

  FIG. 11 shows a schematic structural diagram of a signal channel correction compensation device according to an embodiment of the present invention. This device is arranged in an antenna system. The signal channel correction compensation device 1100 includes a communication interface 1101, a memory 1103, and a processor 1102. Communication interface 1101, processor 1102, and memory 1103 are interconnected using bus 1104. Bus 1104 may be a peripheral component interconnect (PCI for short) bus or an extended industry standard architecture (EISA for short) bus or the like. The bus may be classified as an address bus, a data bus, a control bus, or the like. For simplicity, bus 1104 is represented in FIG. 11 using only one thick line, but this does not indicate that there is only one bus or one type of bus. .

  The communication interface 1101 is configured to communicate with the transmission end. The memory 1103 is configured to store a program. In particular, the program may include program code, which includes computer operating instructions. The memory 1103 may include random access memory (RAM for short) and may further include non-volatile memory (eg, at least one magnetic disk storage).

  The processor 1102 performs the method of the above method embodiment of the present invention by executing a program stored in the memory 1103.

This method
Receiving each received signal from the correction reference channel of the wireless remote unit RRU, each received signal being output correspondingly from each transmission channel after the device has transmitted the transmission correction reference signal to each transmission channel of the RRU And calculating a channel delay of each transmission channel according to each received signal,
Calculating a compensation factor for each transmission channel using the transmission channel corresponding to the minimum channel delay as a transmission reference channel;
Performing correction compensation on each transmission channel according to the compensation coefficient of each transmission channel, the amount of the received signal is a positive integer greater than 1, and the amount of the received signal is equal to the amount of the transmission channel.

  The processor 1102 may be a general-purpose processor including a central processing unit (CPU for short) and a network processor (NP for short), a digital signal processor (DSP), and an application-specific integration. It may be a circuit (ASIC), a field programmable gate array (FPGA) or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component.

  According to the signal channel correction compensation method, apparatus, device, and system of the embodiments of the present invention, when obtaining the compensation coefficient of the signal channel, the transmission channel corresponding to the minimum channel delay is used as the transmission reference channel. Thus, it is possible to effectively prevent the current received segment from including the symbol sampling point of the next segment, and ISI that occurs in this case can be avoided.

  One skilled in the art can appreciate that all or part of the steps of the method embodiments may be implemented by a program that instructs the associated hardware. The program may be stored in a computer readable storage medium. When the program is executed, the steps of the method embodiments are executed. The storage medium includes any medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

  Finally, it should be noted that the above-described embodiments are merely illustrative of the technical solutions of the present invention and do not limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art will be able to describe the above embodiments without departing from the scope of the technical solutions of the embodiments of the present invention. It should be understood that the technical solution can be further modified, or an equivalent exchange of some or all of its technical features can be made.

1 Transmit antenna
2 RRU
3 BBU
4 Correction reference channel
5 Coupling circuit
6 Feeder
41 Receiver unit
42 channel delay calculation unit
43 Compensation coefficient calculation unit
44 Compensation compensation unit
1100 Signal channel compensation compensation device
1101 Communication interface
1102 processor
1103 memory
1104 bus

Optionally, compensation coefficient calculating unit calculates the initial correction compensation coefficient of each transmission channel according to the frequency domain channel response of each transmission channel,
Especially to calculate the compensation coefficient of each transmission channel using the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay based constructed.

According to a fourth aspect, an embodiment of the present invention is a signal channel correction compensation device, wherein the device is arranged in an antenna system,
A communication interface, a memory, a processor, and a communication bus, wherein the communication interface, the memory, and the processor communicate with each other using the communication bus;
Memory is configured to store a program, the processor is configured to execute a program stored in the memory, the program is,
Receiving each received signal from the correction reference channel of the wireless remote unit RRU, each received signal being output correspondingly from each transmission channel after the device has transmitted the transmission correction reference signal to each transmission channel of the RRU A step signal,
Calculating a channel delay of each transmission channel according to each received signal;
Calculating a compensation factor for each transmission channel using the transmission channel corresponding to the minimum channel delay as a transmission reference channel;
Performing correction compensation for each transmission channel according to the compensation coefficient of each transmission channel, and
The amount of received signal is a positive integer greater than 1, and the amount of received signal is equal to the amount of transmission channel;
A signal channel correction compensation device is provided.

Alternatively, in the CL-MIMO transmission technique, the transmission channel response is matched by using time domain or frequency domain compensation, which is expressed as:
β _{tx, 0} × h _{tx, 0} (k) = β _{tx, 1} × h _{tx, 1} (k) = L = β _{tx, 3} × h _{tx, 3} (k)
_{However, β tx, 0 ~β tx,} 3 shows the respective correction compensation coefficient of the transmission channel 0 transmit channel 3.

Alternatively, in the BF transmission technique, the response of the transmission channel is matched by using time domain or frequency domain compensation, ie, the equation

The above method in the embodiment corresponding to FIG. 6 and FIG. 7 can be applied to an antenna system including a single RRU in a single cell, or to an antenna system including a plurality of RRUs in a single cell. Can be applied. For example, as shown in FIG. 8, one antenna system may include two RRUs, and each RRU may include two signal channels.

After receiving the reception signal output by each RRU, the BBU calculates a correction compensation coefficient for each transmission channel according to the method of the embodiment corresponding to FIG. 6 or FIG . The method for calculating the correction compensation coefficient is the same as that of the embodiment corresponding to FIG. 6 or FIG. 7 , and detailed description thereof is omitted.

In consideration of fluctuations in the channel response of the RRU transmission channel and the reception channel, the BBU does not start channel correction until the channel response is stabilized. That, BBU determines whether the startup time of the RRU exceeds X minutes, if the start time of the RRU exceeds X minutes, it channel response is stable, that it is possible BBU performs channel compensation means.

Step S36: The BBU selects channel 0 (random selection is possible) as a reception reference channel according to the obtained LS channel estimation value, uses the initial reception correction coefficient of the reception reference channel as a normalization coefficient, Relative correction processing is performed, that is, all initial reception correction coefficients are divided by the reference channel initial reception correction coefficients to obtain a second reception correction coefficient (this step may not be performed in an FDD system). .

In the above embodiments, the compensation coefficient calculating unit 43 calculates an initial correction compensation coefficient of each transmission channel according to the frequency domain channel response of each transmission channel,
Especially to calculate the compensation coefficient of each transmission channel using the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay based constructed.

Claims (21)

A signal channel correction compensation method comprising:
Receiving each received signal from the correction reference channel of the wireless remote unit RRU by the baseband unit BBU, wherein each received signal is transmitted after the BBU has transmitted a transmission correction reference signal to each transmission channel of the RRU; A signal correspondingly output from each of the transmission channels, and
Calculating a channel delay of each transmission channel according to each received signal by the BBU;
Calculating a compensation coefficient for each transmission channel by using the transmission channel corresponding to the minimum channel delay as a transmission reference channel by the BBU; and
Performing correction compensation on each transmission channel according to the compensation coefficient of each transmission channel by the BBU, and the amount of the reception signal is a positive integer greater than 1, and the reception signal An amount equal to the amount of the transmission channel,
Signal channel correction compensation method. The step of calculating a channel delay of each transmission channel according to each received signal by the BBU,
Calculating a frequency domain channel response of each transmission channel according to each received signal received by the BBU;
2. The method according to claim 1, comprising: calculating, by the BBU, the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel. The step of calculating a frequency domain channel response of each transmission channel according to each received signal received by the BBU,
By the BBU, the formula

Calculating the frequency domain channel response of each transmission channel according to:
s _{tx, i} (k) indicates a correction reference signal transmitted by the BBU to the i th transmission channel of the _RRU, and r _{rxc, i} (k) is received by the correction reference channel. Indicates the received signal corresponding to the first transmission channel, k indicates the sequence number of the frequency domain subcarrier, the value range of k is 0 to N−1, and N is the total amount of frequency domain subcarriers. Yes, the range of the value of i is from 0 to a number obtained by subtracting 1 from the total amount of the transmission channels of the RRU, i and k are both integers of 0 or more, and N is a positive integer is there,
The method of claim 2. The step of calculating a compensation coefficient for each transmission channel by the BBU using a transmission channel corresponding to a minimum channel delay as a transmission reference channel,
Calculating an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel by the BBU;
The method according to claim 2 or 3, comprising: calculating, by the BBU, the compensation coefficient of each transmission channel using an initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay as a reference. . The step of calculating an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel by the BBU,
5. The method of claim 4, comprising obtaining the initial correction compensation factor for each transmission channel by calculating an inverse of the frequency domain channel response for each transmission channel with the BBU. The step of calculating, by the BBU, the compensation factor of each transmission channel using an initial correction compensation factor of the transmission channel corresponding to the minimum channel delay as a reference,
Obtaining the compensation coefficient of each transmission channel by dividing the initial correction compensation coefficient of each transmission channel by the BBU by the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay. The method according to claim 4 or 5. The BBU is connected to a plurality of RRUs;
The step of receiving each received signal from the correction reference channel of the wireless remote unit RRU by the baseband unit BBU,
Receiving each received signal from each correction reference channel of the RRU by the BBU, wherein each received signal transmits a transmission correction reference signal to each transmission channel of the plurality of RRUs; The method according to claim 1, further comprising: a signal that is output correspondingly from each transmission channel of the plurality of RRUs. A signal channel correction compensation device, wherein the device is arranged in a baseband unit BBU,
Each receiving signal from the correction reference channel of the radio remote unit RRU, wherein each received signal is transmitted after the BBU transmits a transmission correction reference signal to each transmission channel of the RRU. A signal output correspondingly from each transmission channel, wherein the amount of the received signal is a positive integer greater than 1, and the amount of the received signal is equal to the amount of the transmission channel so as to perform reception A receiving unit comprising:
A channel delay calculation unit configured to calculate a channel delay of each transmission channel according to each received signal;
A compensation coefficient calculation unit configured to calculate a compensation coefficient for each transmission channel using a transmission channel corresponding to a minimum channel delay as a transmission reference channel;
A signal channel correction compensation apparatus comprising: a correction compensation unit configured to perform correction compensation on each transmission channel according to the compensation coefficient of each transmission channel.   The channel delay calculation unit calculates a frequency domain channel response of each transmission channel according to each received signal received, and calculates the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel. 9. The apparatus of claim 8, wherein the apparatus is specially constructed. The channel delay calculation unit has the formula

Is specifically configured to calculate the frequency domain channel response of each transmission channel according to:
s _{tx, i} (k) indicates a correction reference signal transmitted by the BBU to the i th transmission channel of the _RRU, and r _{rxc, i} (k) is received by the correction reference channel. Indicates the received signal corresponding to the first transmission channel, k indicates the sequence number of the frequency domain subcarrier, the value range of k is 0 to N−1, and N is the total amount of frequency domain subcarriers. Yes, the range of the value of i is from 0 to a number obtained by subtracting 1 from the total amount of the transmission channels of the RRU, i and k are both integers of 0 or more, and N is a positive integer is there,
The apparatus according to claim 9. The compensation factor calculation unit calculates an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel;
11. The apparatus according to claim 9 or 10, wherein the apparatus is specifically configured to calculate the compensation factor for each transmission channel using an initial correction compensation factor for the transmission channel corresponding to the minimum channel delay as a reference.   12. The compensation factor calculation unit is specifically configured to obtain the initial correction compensation factor for each transmission channel by calculating the reciprocal of the frequency domain channel response of each transmission channel. apparatus.   The compensation coefficient calculation unit obtains the compensation coefficient for each transmission channel by dividing the initial correction compensation coefficient for each transmission channel by the initial correction compensation coefficient for the transmission channel corresponding to the minimum channel delay. 13. Apparatus according to claim 11 or 12, specially configured as follows. The BBU is connected to a plurality of RRUs;
The receiving unit receives the reception signals from the correction reference channels of the RRUs, and the reception signals are transmitted by the BBU to the transmission channels of the plurality of RRUs. A signal that is output correspondingly from each of the transmission channels of the plurality of RRUs, and is specifically configured to receive,
The apparatus according to any one of claims 8 to 13. An antenna system comprising an antenna, a radio remote unit RRU, and a baseband unit BBU,
The RRU includes a correction reference channel and a plurality of transmission channels, the correction reference channel is connected to both the antenna and the BBU, and the plurality of transmission channels are connected in parallel between the antenna and the BBU. Connected,
The BBU is configured to perform correction compensation for each transmission channel of the RRU, and the correction compensation is:
The BBU receives each received signal from the correction reference channel of the RRU, and each received signal is transmitted after the BBU transmits a transmission correction reference signal to each transmission channel of the RRU. Receiving a signal correspondingly output from the channel;
The BBU calculates a channel delay of each transmission channel according to each received signal;
The BBU calculates a compensation coefficient for each transmission channel using a transmission channel corresponding to a minimum channel delay as a transmission reference channel;
The BBU performs correction compensation on each transmission channel according to the compensation coefficient of each transmission channel; and
The amount of the received signal is a positive integer greater than 1, and the amount of the received signal is equal to the amount of the transmission channel;
Antenna system.   The BBU is particularly configured to calculate a frequency domain channel response of each transmission channel according to each received signal received, and to calculate the channel delay of each transmission channel according to the frequency domain channel response of each transmission channel 16. The system of claim 15, wherein: The BBU is a formula

Is specifically configured to calculate the frequency domain channel response of each transmission channel according to:
s _{tx, i} (k) indicates a correction reference signal transmitted by the BBU to the i th transmission channel of the _RRU, and r _{rxc, i} (k) is received by the correction reference channel. Indicates the received signal corresponding to the first transmission channel, k indicates the sequence number of the frequency domain subcarrier, the value range of k is 0 to N−1, and N is the total amount of frequency domain subcarriers. Yes, the range of the value of i is from 0 to a number obtained by subtracting 1 from the total amount of the transmission channels of the RRU, i and k are both integers of 0 or more, and N is a positive integer is there,
The system according to claim 16.   The BBU is specifically configured to calculate an initial correction compensation factor for each transmission channel according to the frequency domain channel response of each transmission channel, and further, the initial correction compensation factor for the transmission channel corresponding to the minimum channel delay 18. A system according to claim 16 or 17, wherein the system is specially configured to calculate the compensation factor for each transmission channel using as a reference.   19. The system of claim 18, wherein the BBU is specifically configured to obtain the initial correction compensation factor for each transmission channel by calculating an inverse of the frequency domain channel response for each transmission channel.   In particular, the BBU obtains the compensation coefficient of each transmission channel by dividing the initial correction compensation coefficient of each transmission channel by the initial correction compensation coefficient of the transmission channel corresponding to the minimum channel delay. 20. A system according to claim 18 or 19, wherein the system is configured. The BBU is connected to a plurality of RRUs;
The BBU receives each received signal from each correction reference channel of each of the RRUs, and each of the received signals transmits a transmission correction reference signal to each transmission channel of the plurality of RRUs. A signal that is output correspondingly from each of the transmission channels of the plurality of RRUs, and is specifically configured to receive,
21. A system according to any one of claims 15 to 20.

Images