CN103546398B - A kind of long evolving system adjacent cell measurement method and device - Google Patents

Abstract

The invention discloses a method and device for measuring adjacent cells of a long-term evolution system. After descrambling an extracted reference signal to obtain an estimated channel value of the reference signal, according to different channel conditions or scenarios, using adjacent positions on the same subcarrier, Alternatively, the channel estimation values of reference signals at adjacent positions on the same OFDM symbol are mutually descrambled, and the values obtained by mutual descrambling are accumulated to obtain the RSRP value. The present invention eliminates the channel effect well by using different descrambling methods under different channel conditions or scenarios.

Description

A long-term evolution system neighbor cell measurement method and device

technical field

The present invention relates to the technical field of mobile communication, in particular to a method and device for measuring neighboring cells of a long-term evolution system.

Background technique

Neighboring cell measurement information is the key information for cell camping, reselection and handover in a mobile communication system. In most designs of the existing LTE (Long Term Evolution) system about the measurement of adjacent cells, basically only RSRP (Reference Signal Received Power) and RSSI (Received Signal Power Indication) are measured, but RSP (Reference Signal Power ) for measurement; in addition, when measuring RSRP, channel estimation is generally performed on the received reference signal, and some form of average accumulation is performed on the obtained channel estimation values, and then simple noise elimination is performed to obtain the RSRP value.

In summary, there are following defects or deficiencies in the prior art:

1. The existing RSRP measurement basically performs channel estimation on the received reference signal, and performs some form of average accumulation on the obtained channel estimation values, and then performs simple noise elimination to obtain the RSRP value. ) or Doppler frequency shift (time selective fading) channel conditions will affect the measurement performance;

2. Lack of support for multi-mode LTE auxiliary mode and beamforming scene measurement;

3. The lack of RSP measurement cannot provide the necessary reference for AGC (Automatic Gain Control) adjustment.

Contents of the invention

The technical problem solved by the present invention is to provide a long-term evolution system neighbor cell measurement method and device, which can well eliminate the channel effect by using different descrambling methods under different channel conditions or scenarios.

In order to solve the above technical problems, the present invention provides a long-term evolution system neighbor cell measurement method, after descrambling the extracted reference signal to obtain the channel estimation value of the reference signal,

According to different channel conditions or scenarios, use the channel estimation values of reference signals at adjacent positions on the same subcarrier or adjacent positions on the same Orthogonal Frequency Division Multiplexing (OFDM) symbol to perform mutual descrambling, and to descramble each other The obtained values are accumulated to obtain a reference signal received power (RSRP) value.

Further, the adjacent position on the same subcarrier refers to the same position of adjacent symbols with the same serial number of OFDM symbols on the same subcarrier.

Further, the mutual descrambling refers to: conjugate multiplication of the channel estimation values of the reference signals at the adjacent positions.

Further, according to different channel conditions, it refers to: under the channel condition of multipath effect, select and use the channel estimation value of the reference signal at the adjacent position on the same subcarrier for mutual descrambling, and under the channel condition of Doppler frequency shift The next option is to use channel estimation values of reference signals at adjacent positions on the same OFDM symbol for mutual descrambling.

Further, according to different scenarios, it refers to: selecting and using channel estimation values of reference signals at adjacent positions on the same OFDM symbol to perform mutual descrambling in a multi-mode LTE secondary mode or beamforming scenario.

Further, the method also includes:

Accumulate the extracted power values of the reference signals to obtain a reference signal power (RSP) value.

The present invention also provides a long-term evolution system neighbor cell measurement device, the device comprising:

A reference signal extraction module, configured to extract a reference signal at a corresponding position in the online data according to the configuration;

A scrambling code generation module, configured to generate a corresponding local reference signal scrambling code according to configuration;

A descrambling module, configured to use the local reference signal scrambling code to descramble the extracted reference signal to obtain a channel estimation value of the reference signal;

The RSRP calculation module is used to perform mutual descrambling using the channel estimation values of reference signals at adjacent positions on the same subcarrier or adjacent positions on the same OFDM symbol according to different channel conditions or scenarios, and perform mutual descrambling on the obtained The values are accumulated to obtain the RSRP value.

Further, the RSRP calculation module is used to, according to different channel conditions, select and use channel estimation values of reference signals at adjacent positions on the same subcarrier to perform mutual descrambling under multipath effect channel conditions. Under the channel shift condition, the channel estimation values of reference signals at adjacent positions on the same OFDM symbol are selected for mutual descrambling.

Further, the RSRP calculation module is used to, according to different scenarios, select and use channel estimation values of reference signals at adjacent positions on the same OFDM symbol to perform mutual descrambling in multi-mode LTE auxiliary mode or beamforming scenarios.

Further, the device also includes an RSP calculation module,

The RSP calculation module is configured to accumulate the extracted power values of the reference signals to obtain an RSP value.

Adopt the present invention, compared with prior art, at least have following beneficial effect:

1) Under different channel conditions, different methods are used to descramble the channel estimation value of the reference signal, which eliminates the multipath effect or the channel effect of Doppler frequency shift, and effectively improves the measurement performance;

2) Strong adaptability, can effectively support complex channel conditions with multipath effect and Doppler frequency shift characteristics, and neighbor cell measurement functions in multiple scenarios of multi-mode LTE auxiliary mode and beamforming, which improves the measurement capability;

3) Provides the RSP measurement function to provide the necessary reference for AGC adjustment;

4) The measurement parameters provided are complete, including RSRP, RSSI, and RSP, and support flexible configuration of RSRP, RSSI, and RSP measurements, which greatly reduces hardware power consumption and avoids waste of power consumption.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

FIG. 1 is a schematic diagram of reference signal extraction positions;

FIG. 2 is a schematic diagram of RSRP descrambling of the same carrier according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of RSRP descrambling of the same symbol according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of realizing RSRP measurement according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a neighboring cell measurement device according to an embodiment of the present invention.

Detailed ways

This implementation mode provides a method for measuring neighboring cells in an LTE system, and adopts the following scheme:

After descrambling the extracted reference signal to obtain the channel estimation value of the reference signal, according to different channel conditions or scenarios, use the channel estimation value of the adjacent position on the same subcarrier or the adjacent position on the same OFDM symbol to perform mutual descrambling, and accumulate the values obtained by mutual descrambling to obtain the RSRP value.

Further, the adjacent position on the same subcarrier refers to the same position of adjacent symbols with the same serial number of OFDM symbols on the same subcarrier.

Further, the mutual descrambling includes but is not limited to: conjugate multiplication of channel estimation values of the reference signals at the adjacent positions.

This embodiment also provides an LTE system neighbor cell measurement device, including:

A reference signal extraction module, configured to extract a reference signal at a corresponding position in the online data according to the configuration;

A scrambling code generation module, configured to generate a corresponding local reference signal scrambling code according to configuration;

A descrambling module, configured to use the local reference signal scrambling code to descramble the extracted reference signal to obtain a channel estimation value of the reference signal;

The RSRP calculation module is used to perform mutual descrambling using the channel estimation values of reference signals at adjacent positions on the same subcarrier or adjacent positions on the same OFDM symbol according to different channel conditions or scenarios, and perform mutual descrambling on the obtained The values are accumulated to obtain the RSRP value.

Further, the RSRP calculation module is used to, according to different channel conditions, select and use channel estimation values of reference signals at adjacent positions on the same subcarrier to perform mutual descrambling under multipath effect channel conditions. Under the channel shift condition, the channel estimation values of reference signals at adjacent positions on the same OFDM symbol are selected for mutual descrambling.

Further, the RSRP calculation module is used to, according to different scenarios, select and use channel estimation values of reference signals at adjacent positions on the same OFDM symbol to perform mutual descrambling in multi-mode LTE auxiliary mode or beamforming scenarios.

Further, the device also includes an RSP calculation module,

The RSP calculation module is configured to accumulate the extracted power values of the reference signals to obtain an RSP value.

In order to facilitate the description of the present invention, the implementation of the technical solutions of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other.

The specific process of the neighbor cell measurement in the embodiment of the present invention includes the following main steps:

Step 1: Extract the reference signal of the corresponding position according to the configuration.

Figure 1 is a schematic diagram of the position of an RB (transmission resource block) and a reference signal in the LTE system. What is shown in Figure 1 is a special form (that is, the remainder of the modulo 6 is exactly 0), and the actual position is based on the cell ID (serial number) offset, the offset position v _shift follows the following formula:

Among them, v _shift is the offset value, is the cell ID.

In addition, it can be seen from Figure 1 that according to the different symbol numbers (l) of reference signal 0 (R ₀ ) and reference signal 1 (R ₁ ) (l=0, l=4), the position of the reference signal has an initial offset Shift v, and then fire every 6 REs (resource particles).

Therefore, a state machine with 6 states (such as states 0, 1, 2, 3, 4, 5) is used, and the reference signal is extracted at a position where the state is equal to (v+v _shift ) mod6.

Step 2: When extracting the reference signal, a corresponding local reference signal scrambling code is generated to descramble the extracted reference signal. The local reference signal scrambling code is generated according to the following formula:

Among them, n _s is the time slot sequence number of a radio frame, and l is the OFDM symbol sequence number in a time slot.

The pseudo-random sequence c(n) is generated by two m-sequences with a length of 31 through cyclic shift, and m is the subcarrier sequence number.

Step 3: Use the local reference signal scrambling code to descramble the extracted reference signal, and obtain the channel estimation value of the reference signal through conjugate multiplication. The specific formula is as follows:

Among them, R(n _s , l, m) is the extracted reference signal, Scrambling for the local reference signal.

Step 4: According to different channel conditions and different scenarios, use different methods to descramble the channel estimation values obtained in step 3 to eliminate channel effects, and accumulate the descrambled values to obtain the RSRP value.

Wherein, the mutual descrambling refers to performing conjugate multiplication of obtained channel estimation values of reference signals at different positions to eliminate channel effects. Specifically, the following two methods can be used:

1. Normal mode measurement

Figure 2 is a schematic diagram of the mutual descrambling position of reference signal channel estimates in normal mode. The reference signal channel estimates at the same positions (two adjacent l=0 positions and two adjacent l=4 positions in FIG. The value of disturbance is accumulated and processed to obtain the RSRP value.

In this way, the channel estimation values in the same subcarrier are used for mutual descrambling, which can well overcome the problem of large channel response changes on different subcarriers under frequency selective fading channel conditions.

It should be noted that the channel estimation value obtained in the above step 3 is a vector, that is to say, it is directional, and since the directions are different, the result of accumulation may be very small if the accumulation is performed at this time; and the present invention utilizes Under frequency-selective channel conditions, the channel estimates on the same subcarrier are similar. First, the channel estimates at adjacent positions on the same subcarrier are conjugated and multiplied. At this time, the channel estimate is equivalent to an autocorrelation operation. All The direction of the result after conjugate multiplication will be very close, and then the accumulation performance will be greatly improved.

2. Single symbol mode measurement

Figure 3 is a schematic diagram of the mutual descrambling of reference signal channel estimates in single-symbol mode. At this time, only one OFDM symbol containing a reference signal is used, and reference signals at adjacent positions on the same OFDM symbol (that is, symbols in the same column) are used The channel estimation values are mutually descrambled, and then the descrambled values are accumulated to obtain the RSRP value.

Since this method uses channel estimation values in the same symbol for mutual descrambling, it can well overcome the problem of large channel response changes at different times under time-selective fading channel conditions. The measurement requirements can also be met in the auxiliary mode and the beamforming scenario, which improves the measurement capability.

It should be noted that both the descrambling in step 3 and the descrambling in step 4 above belong to descrambling, but they belong to different stages and have different purposes: step 3 is to use the local reference signal scrambling code to descramble the extracted reference signal Scrambling, the purpose is to obtain channel estimates; and step 4 is to descramble the obtained channel estimates to eliminate channel effects.

Step 5: Perform power calculation on the symbols containing the reference signal, and accumulate to obtain RSSI.

Step 6: Perform power calculation on the extracted reference signals, and accumulate them to obtain RSP.

As shown in Figure 4, the brief process of RSRP calculation is firstly extracted and stored in the memory (Mem), and then the reference signal extracted from the adjacent position is used for conjugate multiplication, and then the local reference signal is used for scrambling It is descrambled, and finally the obtained descrambled result is accumulated in RS Reg (RS register) to obtain the RSRP value.

As shown in Figure 5, the neighboring cell measurement device according to the embodiment of the present invention mainly includes the following functional modules: reference signal extraction module, scrambling code generation module, descrambling module, RSRP calculation module, Meas ram, power calculation module, RSSI Calculation module, RSP calculation module. The specific functions of each module are described as follows:

Reference signal extraction module: mainly used to extract the reference signal of the corresponding position in the online data according to the configuration.

Scrambling code generation module: mainly used to generate the corresponding local reference signal scrambling code according to the configuration.

Descrambling module: mainly used for descrambling using the local reference signal scrambling code and the online extracted reference signal to obtain the channel estimation value of the reference signal.

RSRP calculation module: mainly used for mutual descrambling by using channel estimation values of reference signals on the same symbol or on the same carrier according to different channel conditions or scenarios, eliminating channel effects, and accumulating to obtain RSRP values.

Meas_ram: Mainly used to store the extracted reference signal.

Power Calculation Module: Mainly used to calculate the power value of symbols containing reference signals. This module is an optional module. In practical applications, the power calculation is regarded as a separate module for the convenience of multiplexing power calculation resources, but the completed power calculation can also be completed inside each calculation module.

RSSI calculation module: mainly used to accumulate the power values of the symbols containing the reference signal to obtain the RSSI value.

RSP calculation module: mainly used to accumulate the power value of the corresponding reference signal according to the configuration to obtain the RSP value.

The above are only preferred implementation examples of the present invention, and are not intended to limit the present invention. The present invention can also have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can Various corresponding changes and modifications are made in the present invention, but these corresponding changes and modifications should all belong to the protection scope of the appended claims of the present invention.

Obviously, those skilled in the art should understand that each module or each step of the above-mentioned present invention can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed in a network formed by multiple computing devices Alternatively, they may be implemented in program code executable by a computing device so that they may be stored in a storage device to be executed by a computing device, and in some cases in an order different from that shown here The steps shown or described are carried out, or they are separately fabricated into individual integrated circuit modules, or multiple modules or steps among them are fabricated into a single integrated circuit module for implementation. As such, the present invention is not limited to any specific combination of hardware and software.

Claims (9)

1. A long-term evolution system neighbor cell measurement method, characterized in that, after descrambling the extracted reference signal to obtain the channel estimate of the reference signal, According to different channel conditions or scenarios, use the channel estimation values of reference signals at adjacent positions on the same subcarrier or adjacent positions on the same Orthogonal Frequency Division Multiplexing (OFDM) symbol to perform mutual descrambling, and to descramble each other The obtained values are accumulated to obtain a reference signal received power (RSRP) value; Wherein, the adjacent position on the same subcarrier refers to the same position of adjacent symbols with the same serial number of OFDM symbols on the same subcarrier. 2. The method of claim 1, wherein The mutual descrambling refers to: conjugate multiplication of the channel estimation values of the reference signals at the adjacent positions. 3. The method of claim 1 or 2, wherein, According to different channel conditions, it refers to: under the channel condition of multipath effect, select to use the channel estimation value of the reference signal at the adjacent position on the same subcarrier for mutual descrambling; under the condition of Doppler frequency shift channel, select to use The channel estimation values of reference signals at adjacent positions on the same OFDM symbol are mutually descrambled. 4. The method of claim 1 or 2, wherein, According to different scenarios, it refers to: selecting and using channel estimation values of reference signals at adjacent positions on the same OFDM symbol to perform mutual descrambling in a multi-mode LTE secondary mode or beamforming scenario. 5. method as claimed in claim 1 or 2, is characterized in that, described method also comprises: Accumulate the extracted power values of the reference signals to obtain a reference signal power (RSP) value. 6. A long-term evolution system neighbor cell measurement device, characterized in that the device comprises: A reference signal extraction module, configured to extract a reference signal at a corresponding position in the online data according to the configuration; A scrambling code generation module, configured to generate a corresponding local reference signal scrambling code according to configuration; A descrambling module, configured to use the local reference signal scrambling code to descramble the extracted reference signal to obtain a channel estimation value of the reference signal; The RSRP calculation module is used to perform mutual descrambling using the channel estimation values of reference signals at adjacent positions on the same subcarrier or adjacent positions on the same OFDM symbol according to different channel conditions or scenarios, and perform mutual descrambling on the obtained The values are accumulated to obtain the RSRP value. 7. The apparatus of claim 6, wherein The RSRP calculation module is used to, according to different channel conditions, select and use channel estimation values of reference signals at adjacent positions on the same subcarrier under multipath effect channel conditions for mutual descrambling, and under Doppler frequency shift channel conditions The next option is to use channel estimation values of reference signals at adjacent positions on the same OFDM symbol for mutual descrambling. 8. The apparatus of claim 6, wherein The RSRP calculation module is used to select and use channel estimation values of reference signals at adjacent positions on the same OFDM symbol for mutual descrambling in multi-mode LTE secondary mode or beamforming scenarios according to different scenarios. 9. The device according to claim 6, 7 or 8, characterized in that the device also comprises an RSP calculation module, The RSP calculation module is configured to accumulate the extracted power values of the reference signals to obtain an RSP value.