RU2840961C1 - Method of processing received uplink control channel signal - Google Patents

Abstract

FIELD: telecommunications.

SUBSTANCE: based on the channel response estimate, combining the estimates of sufficient statistics of the useful parameter for each user device along each slot and receiving channel; estimating the received reference signal of each user device; estimating the interfering noise parameter sufficient statistics by excluding the estimate of the received reference signal of each user device from the received signal; based on estimates of sufficient statistics of useful parameters of user devices and sufficient statistics of the interfering noise parameter, determining presence or absence of a signal from the user device at the input.

EFFECT: high noise-immunity of the method of processing a received uplink control channel signal while limiting the required number of calculations in conditions for unknown channel characteristics and noise characteristics during simultaneous reception of a signal from one or more user devices.

5 cl, 3 dwg

Description

The invention relates to a method for processing a received signal of an uplink control channel (PUCCH, abbreviation for Physical Uplink Control Channel) and can be used in LTE and 5G wireless communication systems used in the field of telecommunications.

A radio communication method was chosen as a prototype, during which the following is carried out:

- receiving and demodulating downlink common channel signals for each of a plurality of primary frequency blocks transmitted from a base radio station device;

- detecting the state of the retransmission confirmation signal of each of the plurality of blocks of basic frequencies based on the demodulated signals of the common downlink channel;

- mapping the retransmission confirmation signals of a plurality of base frequency blocks to an uplink control channel (PUCCH) of a specific base frequency block selected from the plurality of base frequency blocks, wherein in the step of mapping the retransmission confirmation signals of the plurality of base frequency blocks, the mobile terminal device selects a plurality of allocated resources from the uplink control channel (PUCCH) and determines the states of the retransmission confirmation signals of the plurality of base frequency blocks using bit information through phase modulation and channel selection information. [EP 2608616 A1, published 26.06.2013].

A disadvantage of the prototype is the lack of a detailed description of the method for detecting the received uplink control channel (PUCCH) signal in an environment with unknown parameters in the case of multichannel reception.

The technical problem that the invention is aimed at solving is the detailing of the algorithm for detecting the uplink control channel signal, capable of fulfilling the requirements of the 3GPP TS 36.141 specification.

The technical result, which the invention is aimed at achieving, consists in increasing the noise immunity of the method for processing the received signal of the control channel of the uplink communication line while limiting the required number of calculations under unknown conditions: channel characteristics and noise characteristics during the simultaneous reception of a signal from one or more user devices.

The essence of the invention is as follows.

The method for processing a received uplink control channel (PUCCH) signal includes the steps of performing, by means of an electronic computing device:

- evaluate the characteristics of the communication channel with each user device by removing modulation from the received reference signal (DMRS, abbreviation for Demodulation reference signal);

- the obtained channel characteristic estimate is averaged for each user device and each slot of the receiving channel;

- evaluate sufficient statistics of the useful parameter for each user device in each slot and receiving channel;

- based on the assessment of the channel characteristics, a combination of assessments of sufficient statistics of the useful parameter is performed for each user device along each slot and receiving channel;

- evaluate the received reference signal (DMRS) of each user device;

- estimate sufficient statistics of the interfering noise parameter by excluding the estimated received reference signal (DMRS) of each user device from the received signal;

- based on the assessment of sufficient statistics of useful parameters of user devices and sufficient statistics of the interfering noise parameter, the presence or absence of a signal from the user device at the input is determined.

The method of processing the received signal is carried out by synthesizing the algorithm of constant false alarm probability (CFAR, abbreviation for English Constant false alarm rate), as well as algorithms for estimating: sufficient statistics of the interfering noise parameter and sufficient statistics of the useful parameter of the user device.

The channel characteristic is estimated by removing the modulation from the received reference signal, during which the channel estimate is averaged for each user device.

The estimation of sufficient statistics of the useful parameter for each user device in each slot and receiving channel is performed by determining the scalar product of the signal from the user device with the received signal.

The received reference signal (DMRS) of each user device is estimated by combining the useful signal estimates from each slot and the receiving antenna, using the average channel estimate of the given user device as a weighting factor.

The estimation of sufficient statistics of the interfering noise parameter is performed by subtracting the estimation of the received reference signal of each user device from the received reference signal and determining the scalar product of the obtained vector transposed by itself. The estimation of the received signal from the user device is determined as the product of the channel estimation by the value of the reference signal received from the user device.

The presence or absence of a signal at the input is determined by comparing sufficient statistics of the useful parameter of the user device with the product of sufficient statistics of the interfering noise parameter and the coefficient determining the false alarm level. The value of this coefficient is selected to meet the requirements of the 3GPP TS 36.141 standard.

The invention can be made from known materials using known means, which indicates its compliance with the patentability criterion of “industrial applicability”.

The invention is characterized by a previously unknown set of essential features from the state of the art, which makes it possible, through the synthesis of a CFAR algorithm acting as a signal detector, as well as evaluation algorithms: sufficient statistics of the interfering noise parameter and sufficient statistics of the useful parameter of the user device, to determine the presence or absence of a signal from the user device at the input and to minimize distortions of the received signal caused by the impact of signal propagation effects in a medium with unknown parameters.

This ensures the achievement of a technical result consisting in increasing the noise immunity of the method for processing the received signal of the control channel of the uplink communication line while limiting the required number of calculations under unknown conditions: channel characteristics and noise characteristics during the simultaneous reception of a signal from one or more user devices.

The invention has a set of essential features previously unknown in the state of the art, which indicates its compliance with the patentability criterion of “novelty”.

The essential features of the invention are unknown from the prior art, which is why it meets the patentability criterion of “inventive step”.

The invention is illustrated by the following figures.

Fig. 1 - Structural diagram of the method for processing the received signal of the control channel of the uplink communication line.

Fig. 2 - Results of measurements of the probability of occurrence of a false alarm.

Fig. 3 - Results of measurements of the probability of erroneous reception of a transmitted symbol from several user devices.

To illustrate the possibility of implementation and a more complete understanding of the essence of the invention, an embodiment of it is presented below, which can be changed or supplemented in any way, while the present invention is in no way limited to the presented embodiment.

The method for processing the received signal of the uplink control channel (PUCCH) is implemented by the base station at the receiving side of the wireless communication system as follows.

A vector is fed to the input signals from all receiving antennas which is subjected to a cyclic shift and transformed by a fast Fourier transform (FFT).

In accordance with the signal structure described in the standard, reference signals are extracted Where - slot number, - resource element number.

Information symbols are also extracted in accordance with the standard. Where - user device number (UDN), - slot number, - resource element number. After this, the channel characteristics are evaluated

The resulting value of the channel characteristic estimate is averaged.

Then, using the known value of the reference signal (DMRS), an estimate of the sufficient statistics of the useful parameter is determined for each user device for each slot of each receiving channel,

The next step is to combine estimates of sufficient statistics of the useful parameter for each user based on the known estimate of the channel characteristic:

Then, an estimate of sufficient statistics of the interfering noise parameter is determined based on the obtained estimate of the channel characteristic:

The next step is to determine whether there is a signal from the user device. This is done using the following inequality with a threshold value

If the inequality is satisfied, then the signal is present at the input, and if not, then there is no signal at the input. Also, according to the statistics of the useful parameter, it can be determined what information signal was transmitted.

To confirm the achievement of the technical result by the developed method, its statistical testing was carried out. The testing was based on the testing of base station reception algorithms described in 3GPP TS 36.141. As a result, the noise immunity of the algorithm was measured for several cases using the prepared data:

- measuring the probability of a false alarm (Fig. 1).

- measuring the probability of erroneous reception of a transmitted symbol from several user devices (Fig. 2).

Experiments for each test scenario were performed on 8000 test samples. The developed method was tested in both presented cases.

In this way, the technical result is achieved, which consists in increasing the noise immunity of the method for processing the received signal of the control channel of the uplink communication line while limiting the required number of calculations under unknown conditions: channel characteristics and noise characteristics during the simultaneous reception of a signal from one or more user devices.

Claims (12)

1. A method for processing a received signal of an uplink control channel, comprising the steps of performing which, by means of an electronic computing device: - an assessment is made of the characteristics of the communication channel with each user device by removing the modulation from the received reference signal; - the obtained channel characteristic estimate is averaged for each user device and each slot of the receiving channel; - evaluate sufficient statistics of the useful parameter for each user device in each slot and receiving channel; - based on the assessment of the channel characteristics, a combination of assessments of sufficient statistics of the useful parameter is performed for each user device along each slot and receiving channel; - evaluate the received reference signal of each user device; - estimate sufficient statistics of the interfering noise parameter by excluding the estimated received reference signal (DMRS) of each user device from the received signal; - based on the assessment of sufficient statistics of useful parameters of user devices and sufficient statistics of the interfering noise parameter, the presence or absence of a signal from the user device at the input is determined. 2. The method according to paragraph 1, characterized in that the evaluation of useful statistics is performed by determining the scalar product of the signal from the user device and the received signal. 3. The method according to item 1, characterized in that the assessment of sufficient statistics of the interfering noise parameter is performed by subtracting the assessment of the received reference signal of each user device from the received reference signal and determining the scalar product of the obtained vector transposed by itself. 4. The method according to paragraph 3, characterized in that the estimate of the received signal from the user device is determined as the product of the channel estimate and the value of the reference signal received from the user device. 5. The method according to claim 1, characterized in that the presence or absence of a signal at the input is determined by comparing the useful statistics of the user device with the product of sufficient statistics of the interfering noise parameter and a coefficient determining the false alarm level, the value of which is selected to achieve the requirements of the 3GPP TS 36.141 standard.