WO2011143892A1

WO2011143892A1 - Method and device for analyzing uplink broadband interference

Info

Publication number: WO2011143892A1
Application number: PCT/CN2010/077686
Authority: WO
Inventors: 董广明; 张玉杰; 董志峰
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-05-20
Filing date: 2010-10-12
Publication date: 2011-11-24
Also published as: CN102255833B; CN102255833A

Abstract

The present invention discloses a method for analyzing uplink broadband interference, which includes: determining the uplink subframes for broadband interference analysis; collecting statistics of noise power of each subcarrier occupied by each null time slot on each subframe, and counting average noise power of the subcarriers; counting the system noise floor value according to the average noise power of the subcarriers; comparing the counted system noise floor value with the system theoretical noise floor value and obtaining the system broadband interference circumstance. The present invention also discloses a device for analyzing uplink broadband interference. By the present invention, accurate analysis for uplink broadband interference can be implemented with the data service existing and no stopping it.

Description

Analysis method and device for uplink broadband interference

The present invention relates to an Orthogonal Frequency Division Multiple Access (OFDMA) system, and more particularly to an analysis method and apparatus for uplink wideband interference. Background technique

The Orthogonal Frequency Division Multiple Access (OFDMA) communication system uses a wideband signal with a bandwidth ranging from 1.5M to 20M. For broadband systems, it is inevitable that there will be broadband interference.

The existence of uplink broadband interference seriously affects the normal service establishment and data transmission of the communication system. The broadband interference signal exists in the time domain. When receiving the data signal, the base station receives the broadband interference signal at the same time. When doing the Fast Fourier Transform (FFT), the interference and the actual needs are in the frequency domain. The data is aliased together, resulting in incorrect data acquisition during demodulation. However, in the presence of data services, it is difficult to distinguish between broadband interference signals and actual data signals in the frequency domain. Therefore, how to effectively detect and identify broadband interference signals is essential when the communication system is running.

In the existing technology of the OFDMA system, the analysis method for the uplink broadband interference is to stop the uplink service, and the signal noise power value counted by the base station is the bottom noise value of the system, and then judged according to the noise floor value. Is there any broadband interference? The disadvantage of this method is that all users are removed from the base station and the uplink data service is stopped. Such an operation is prohibited in practical applications. How to analyze the broadband interference of the uplink in the presence of data services has not been a very good and accurate method. Summary of the invention

In view of this, the main object of the present invention is to provide an uplink broadband interference analysis method and apparatus, which can accurately detect uplink broadband interference in the presence of data services without stopping data services. analysis.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

The present invention provides an uplink broadband interference analysis method, the method comprising: determining an uplink subframe for performing broadband interference analysis;

Counting the noise power of each subcarrier occupied by each empty slot in each subframe, and calculating the average noise power of the subcarriers;

Calculating a bottom noise value of the system according to an average noise power of the subcarrier;

The calculated bottom noise value of the system is compared with the theoretical bottom noise value of the system to obtain the broadband interference of the system.

The method further includes:

Dividing the last 3 symbols in the time domain and the 35 subchannels in the frequency domain into a partial subchannel area (PUSC zone); and all the time slots (slots) included in the PUSC zone ) is set to empty slot, no uplink data is sent;

The noise power of each subcarrier occupied by each empty slot in the PUSC zone on each of the subframes is counted.

Further, the noise power of each subcarrier is counted, specifically:

PowerSum = I ² + Q ²

The PowenS w is the noise power of a single subcarrier; the / is the real part of the frequency domain data received from a single subcarrier; the β is the imaginary part of the frequency domain data received from a single subcarrier.

Further, the calculating the average noise power of the subcarriers is specifically:

Determining the number of subcarriers for performing broadband interference analysis according to the number of the subframes, and calculating the total noise power of the subcarriers according to the noise power of the subcarriers and the number of subcarriers Μ M

YPowerSum _n , where n is the sequence number of the subcarrier, and M is a natural number; then the average noise power of the subcarrier is:

RssiEverySubCarrier - .

Further, the bottom noise value of the computing system is specifically:

Rssi = 10 log ( RssiEverySubCarrier x N);

Wherein, the system is a bottom noise value of the system; and the N is a number of subcarriers included in one frequency domain symbol of the system.

Further, the calculated bottom noise value of the system is compared with the theoretical bottom noise value of the system, specifically:

Calculate the difference between the calculated bottom noise value of the system and the theoretical bottom noise value of the system ( RssiExp ): Rssilnterfere = Rssi - RssiExp;

According to the difference between the bottom noise value of the system and the theoretical bottom noise value of the system R 7 « er / ere , the broadband interference of the system is obtained.

Further, the broadband interference situation of the system is obtained, specifically: determining a broadband interference condition according to a packet error rate of receiving uplink data and the R 7« er/ere.

The present invention also provides an apparatus for analyzing uplink broadband interference, the apparatus comprising: a pre-processing module, configured to determine an uplink subframe of the broadband interference analysis; and a statistics module, configured to count each of the subframes The noise power of each subcarrier occupied by each empty slot, and calculating the average noise power of the subcarrier; and calculating the bottom noise value of the system according to the average noise power of the subcarrier;

The analysis module is configured to compare the calculated bottom noise value of the system with a theoretical bottom noise value of the system to obtain a broadband interference condition of the system.

The pre-processing module is further configured to divide the last 3 symbols in the time domain and the 35 sub-channels in the frequency domain into one PUSC zone; and the PUSC All slots contained in the zone are set to empty slots;

Correspondingly, the statistics module is further configured to perform statistics on noise power of each subcarrier occupied by each empty slot in the PUSC zone on each subframe.

The analyzing module is further configured to perform a difference calculation between the calculated bottom noise value of the system and a theoretical bottom noise value of the system, and according to the error packet rate of the received uplink data and the bottom noise value of the system and the system The difference in the theoretical bottom noise value determines the broadband interference situation.

The present invention collects the noise power of each subcarrier occupied by each empty slot in the PUSC zone by setting a set of empty slots in the uplink subframe, that is, a PUSC zone, to obtain a bottom noise value of the entire system. At the same time, slots other than the PUSC zone on the subframe can be used for uplink data transmission; then, according to the calculated difference between the bottom noise value of the system and the theoretical bottom noise value of the system, the broadband in the system can be determined. The interference situation, in this way, the present invention can accurately analyze the uplink broadband interference when there is a data service and does not stop the data service. DRAWINGS

1 is a schematic diagram showing the position of an empty slot in a subframe according to the present invention;

2 is a schematic flowchart of an uplink broadband interference analysis method according to the present invention;

FIG. 3 is a schematic structural diagram of an apparatus for analyzing uplink broadband interference according to the present invention. detailed description

The technical solutions of the present invention are further elaborated below in conjunction with the accompanying drawings and specific embodiments. In the 0FDMA system, if the uplink subcarriers are not used all, the terminal will only transmit the uplink data on the designated subcarriers, and there will be an empty slot. The slot is the smallest unit of data in the 0FDMA system. As shown in Figure 1, in the case of the subcarrier (PUSC) used in the uplink part, one slot (slot) occupies 3 symbols in the time domain. One subchannel is occupied in the frequency domain, and one subchannel contains 72 subcarriers. Waves (24 are pilot subcarriers and 48 are data subcarriers).

Although the uplink data is not sent on the empty slot, when the RF receiving device on the network side receives the uplink data, there is still data on the empty slots, and the data is the noise signal of the surrounding environment, and the present invention occupies the empty slots. The power of the noise signal of each subcarrier (referred to as noise power) is counted, and the system noise floor value (Rssi) of the entire bandwidth can be obtained to determine whether there is broadband interference.

Based on the above idea, the technical solution of the present invention is implemented as shown in FIG. 2, including the following steps:

Step 201: Determine an uplink subframe of the broadband interference analysis.

4 叚 In a statistical period, it is necessary to analyze the broadband interference of the uplink continuous M=2 million subcarriers, because the uplink data is in units of subframes, and one subframe occupies 35 subchannels in the frequency domain, and one channel includes 72 subcarriers, that is, one subframe occupies 35 x 72 = 2520 subcarriers in the frequency domain, then about 2000000 ÷ 2502 794 subframes need to be analyzed; in the 0FDMA system, one subframe is 5 ms, then one statistical period Approximately 794 x 5ms = 4s.

In practical applications, the number of statistical subframes can be determined as needed, and the number of subcarriers is M subframes x2520.

In addition, the present invention may further perform the step 202 of wideband interference according to the above determined statistical period, and set the PUSC zone based on each subframe.

In order to reduce the complexity of the subcarrier noise power statistics, the present invention sets an empty slot set, that is, a partial subchannel area (PUSC zone) on each statistical subframe. As shown in FIG. 1, one subframe is in time. The domain occupies 15 symbols, occupies 35 subchannels in the frequency domain, and divides the last 3 symbols and 35 subchannels of one subframe in the time domain into PUSC zones. The PUSC zone contains 35 slots, each slot. Occupying 72 subcarriers, in the present invention, all 35 slots are set to empty slots, that is, the PUSC zone in which one subframe is set does not transmit uplink data; All other slots on the subframe can be used for the transmission of uplink data.

Since the PUSC zone does not send the uplink data, the 35 empty slots included in the PUSC zone do not have a corresponding modulation and coding mode, and the value of the corresponding modulation and coding mode of each empty slot is 0.

Step 203: Count the noise power of each subcarrier occupied by each empty slot.

As can be seen from Fig. 1, an empty slot occupies 72 subcarriers, and the present invention counts the noise power of each subcarrier occupied by each empty slot. The noise power is calculated based on the frequency domain data of each subcarrier, and includes two parts of real (I) and imaginary (Q) data, wherein: the radio receiving device on the network side receives data from a certain subcarrier of an empty slot. At the same time, a 32-bit frequency domain data is obtained, including a 16-bit real part (I) and a 16-bit imaginary part (Q). The imaginary part represents the phase of the sub-carrier, and the real and imaginary parts represent the values. The amplitude of this subcarrier.

Then the noise power of the subcarrier PowerSum = I ² + Q

This method is used to track each empty slot in the PUSC zone in each sub-segment. For an empty slot, the noise power of 72 sub-carriers needs to be counted. The noise power of M sub-carriers needs to be calculated.

Step 204: Calculate an average noise power of the subcarriers. Accumulating the noise power of the counted M subcarriers,

Where n is the sequence number of the subcarrier, M is a natural number, and then divided by the number M of subcarriers, the average noise power of the subcarriers, that is, the noise floor value of each subcarrier is obtained:

RssiEvery Sub Carrier = .

Step 205: Calculate a bottom noise value of the system.

Multiplying the average noise power of the M subcarriers by the number of subcarriers N included in one frequency domain symbol in the 0FDMA system (N=1024 when the system bandwidth is 10M; N=512 when the bandwidth is 10M, 5=, N=512) Obtain the bottom noise value of the system: Rssi = 10 log ( RssiEvery ubCarrier x N). Step 206, comparing the calculated bottom noise value of the system with a theoretical bottom noise value of the system, Get the broadband interference of the system.

The difference between the calculated bottom noise value of the system and the theoretical bottom noise value RssiExp of the system, ie Rssilnterfere = Rssi - RssiExp, is used to judge the wideband interference of the system by the difference Rssilnterfere.

Generally, in the absence of wideband interference, for the OFDMA system, the theoretical bottom noise value R x; of the system obtained through simulation and actual testing is around -102 dB. If broadband interference is present, the system's noise floor value, Rssi, will be too large, exceeding -102dB.

The invention obtains the broadband interference condition according to the error packet rate of receiving the uplink data and the value of the Rssilnterfere, and classifies the bandwidth interference situation, for example, the broadband interference condition is divided into eight levels: 1. When R 7 « er / ere ≤ 10 When it is considered that there is no broadband interference, it will not affect normal data services;

2. When 10≤R^7« er/ere≤20, it is considered that there is slight broadband interference, and there may be a packet error in the uplink data transmission, and the packet error rate will be within 1%;

3. When 20 < R^7« er/ere ≤ 30, it is considered that there is a general degree of broadband interference, there may be less error packets in the uplink data transmission, and the packet error rate will be within 5%;

4. When 30 < R^7« er/ere ≤ 40, it is considered that there is moderate broadband interference, there may be a small amount of error packets in the uplink data transmission, and the packet error rate will be within 10%;

5. When 40 < R^7« er/ere ≤ 50, it is considered that there is serious broadband interference; there may be more error packets in the uplink data transmission, and the packet error rate will be within 50%;

6. When 50 < Rssilnterfere ≤ 60, it is considered that there is more serious broadband interference, there may be a lot of error packets in the uplink data transmission, and the packet error rate will be within 70%;

7. When 60 < R^7« er/ere ≤ 70, it is considered that there is very serious broadband interference, there may be a large number of error packets in the uplink data transmission, and the packet error rate will be within 90%;

8. When Rssilnterfere > 70, then the received system noise power is oversaturated, which exceeds the performance limit that can be demodulated. It is considered that the uplink data is basically unable to transmit normally, and the packet error rate reaches 100%. Based on the above-described hierarchical division, the present invention can accurately analyze the broadband interference of the uplink.

The above eight levels of division are only one embodiment. Of course, according to the actual needs, the broadband interference situation can be more accurately classified according to the error packet rate of receiving the uplink data and the value of the Rssilnterfere.

In order to implement the above analysis method, the present invention provides a device for broadband interference analysis, as shown in FIG. 3, including:

The pre-processing module 10 is configured to determine an uplink subframe of the broadband interference analysis, and the statistics module 20 is configured to calculate a noise power of each sub-carrier occupied by each empty slot in each subframe, and calculate an average of the sub-carriers. Noise power; is also used to calculate the bottom noise value of the system based on the average noise power of the subcarriers;

The analysis module 30 is configured to compare the calculated bottom noise value of the system with the theoretical bottom noise value of the system to obtain a broadband interference condition of the system.

The pre-processing module 10 is further configured to divide the last 3 symbols of each subframe in the time domain and the 35 subchannels in the frequency domain into one PUSC zone; and set all the slots included in the PUSC zone to an empty slot. , no uplink data is sent;

Correspondingly, the statistics module 20 is further configured to perform statistics on the noise power of each subcarrier occupied by each empty slot in the PUSC zone on each subframe.

The analyzing module 30 is further configured to perform a difference calculation between the calculated bottom noise value of the system and the theoretical bottom noise value of the system, and according to the error packet rate of the received uplink data and the bottom noise value of the system and the theoretical bottom noise value of the system. The difference is determined by the broadband interference situation.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

An uplink broadband interference analysis method, the method comprising: determining an uplink subframe for performing broadband interference analysis;

Counting the noise power of each subcarrier occupied by each empty slot (slot) on each subframe, and calculating the average noise power of the subcarriers;

2. The method for analyzing uplink broadband interference according to claim 1, wherein the method further comprises:

And dividing the last 3 symbols of each subframe in the time domain and the 35 subchannels in the frequency domain into a partial subchannel region (PUSC zone);

And setting all slots included in the PUSC zone to empty slots, and not transmitting uplink data;

The method for analyzing the uplink broadband interference according to claim 2, wherein the noise power of each subcarrier is counted, which is specifically:

PowerSum = I ² + Q ²

Wherein the corpse mven M is a noise power of a single subcarrier; the / is a real part of frequency domain data received from a single subcarrier; the ρ is an imaginary part of frequency domain data received from a single subcarrier.

The method for analyzing uplink broadband interference according to claim 3, wherein the calculating the average noise power of the subcarriers is specifically:

Determining the number of subcarriers for performing broadband interference analysis according to the number of the subframes, and calculating the total noise power of the subcarriers according to the noise power of the subcarriers and the number of subcarriers Μ Power Sum _n , where n is the sequence number of the subcarrier, and M is a natural number; then the average noise power of the subcarrier is:

RssiEverySubCarrier = .PowerSum _n M.

The method for analyzing the uplink broadband interference according to claim 4, wherein the bottom noise value of the computing system is specifically:

Rssi = 10 log ( RssiEverySubCarrier X N);

6. The method for analyzing uplink broadband interference according to claim 5, wherein the calculated bottom noise value of the system is compared with a theoretical bottom noise value of the system, specifically: The difference between the bottom noise value of the system and the theoretical bottom noise value of the system ( RssiExp )

The method for analyzing uplink broadband interference according to claim 6, wherein the broadband interference situation of the system is obtained, specifically: determining a bandwidth according to a packet error rate of receiving uplink data and the R 7« er/ere Interference situation.

An apparatus for analyzing uplink broadband interference, the apparatus comprising: a pre-processing module, configured to determine an uplink subframe for performing broadband interference analysis; and a statistics module, configured to count each of the sub-frames The noise power of each subcarrier occupied by each empty slot on the frame, and calculating the average noise power of the subcarrier; and calculating the bottom noise value of the system according to the average noise power of the subcarrier;

The apparatus for analyzing uplink broadband interference according to claim 8, wherein the pre-processing module is further configured to use the last three symbols of each subframe in the time domain and in the frequency domain. The 35 subchannels are divided into one PUSC zone; and all the slots included in the PUSC zone are set to an empty slot;

The apparatus for analyzing uplink broadband interference according to claim 8, wherein the analyzing module is further configured to perform a difference between the calculated bottom noise value of the system and a theoretical bottom noise value of the system. The operation determines the broadband interference condition according to the error packet rate of the received uplink data and the difference between the bottom noise value of the system and the theoretical bottom noise value of the system.