KR-20260067241-A - A MODEM CHIP AND METHOD OF OPERATING THE MODEM CHIP FOR LOG LIKELIHOOD RATIO ADJUSTMENT WITH INFERRING CHANNEL ESTIMATION ERROR

Abstract

A modem chip according to one aspect of the technical concept of the present disclosure may include a Radio Frequency Integrated Circuit (RFIC) configured to receive a data signal and a reference signal through a Precoding Resource Block Group (PRG) comprising a plurality of first subcarriers to which a data signal is assigned and a plurality of second subcarriers to which a reference signal is assigned, and a processor configured to calculate a delay spread value for the data signal using the reference signal, determine a maximum threshold value corresponding to the delay spread value, and calculate at least one Log Likelihood Ratio (LLR) corresponding to at least one first subcarrier based on a tuning coefficient corresponding to the maximum threshold value.

Inventors

• 김주한
• 정영석
• 정재훈

Assignees

• 삼성전자주식회사

Dates

Publication Date

20260512

Application Date

20241105

Claims (10)

1. A Radio Frequency Integrated Circuit (RFIC) configured to receive the data signal and the reference signal through a Precoding Resource Block Group (PRG) comprising a plurality of first subcarriers to which the data signal is assigned and a plurality of second subcarriers to which the reference signal is assigned; and A modem chip comprising a processor configured to calculate a delay spread value for the data signal using a reference signal, determine a maximum threshold value corresponding to the delay spread value, and calculate at least one adjusted Log Likelihood Ratio (LLR) corresponding to at least one first subcarrier based on an adjustment coefficient corresponding to the maximum threshold value.
2. In paragraph 1, Each of the above-mentioned at least one adjustment LLR is, Smaller than at least one existing LLR for each of the at least one first subcarrier corresponding to each of the at least one adjustment LLR, A modem chip characterized in that the smaller the number of the plurality of second subcarriers, the smaller the at least one adjustment LLR.
3. In paragraph 1, Each of the above-mentioned at least one adjustment LLR is, Smaller than at least one existing LLR for each of the at least one first subcarrier corresponding to each of the at least one adjustment LLR, A modem chip characterized in that the larger the above delay spread value, the smaller the above at least one adjustment LLR is.
4. In paragraph 1, A modem chip characterized in that at least one first subcarrier is located at the edge of the PRG.
5. A step of receiving the data signal and the reference signal through a PRG (Precoding Resource block Group) comprising a plurality of first subcarriers to which the data signal is assigned and a plurality of second subcarriers to which the reference signal is assigned; A step of calculating a delay spread value for the data signal using a reference signal; A step of determining a maximum threshold corresponding to the above-mentioned delay spread value; and A method of operation of a modem chip comprising the step of calculating at least one adjusted LLR (Log Likelihood Ratio) corresponding to at least one first subcarrier based on an adjustment coefficient corresponding to the maximum threshold value.
6. In paragraph 5, Each of the above at least one adjustment LLR is, Smaller than the existing LLR for each of the at least one first subcarrier corresponding to each of the at least one adjustment LLR, A method of operation of a modem chip characterized in that the smaller the number of the plurality of second subcarriers, the smaller the at least one adjustment LLR.
7. In paragraph 5, Each of the above-mentioned at least one adjustment LLR is, Smaller than the existing LLR for each of the at least one first subcarrier corresponding to each of the at least one adjustment LLR, A method of operation of a modem chip characterized in that the larger the above delay spread value, the smaller the above at least one adjustment LLR is.
8. In paragraph 5, A method of operation of a modem chip characterized in that at least one first subcarrier is located at the edge of the PRG.
9. A Radio Frequency Integrated Circuit (RFIC) configured to receive the data signal and the reference signal through a Precoding Resource Block Group (PRG) comprising a plurality of first subcarriers to which the data signal is assigned and a plurality of second subcarriers to which the reference signal is assigned; and A modem chip comprising a processor configured to calculate a delay spread value for the data signal using a reference signal, and to determine an adjustment coefficient such that at least one Log Likelihood Ratio (LLR) corresponding to each of at least one first subcarrier located at the edge of the PRG is inversely proportional to the delay spread value.
10. In Paragraph 9, The above processor is, A modem chip characterized in that the smaller the number of the plurality of second subcarriers, the smaller the at least one LLR corresponding to each of the at least one first subcarrier.

Description

A modem chip and method of operating the modem chip for log-likelihood ratio adjustment with inferring channel estimation error The technical concept of the present disclosure relates to a modem chip and a method of operation of the modem chip, and more specifically, to a modem chip and a method of operation of the modem chip that infers the channel estimation error of a received signal based on a delay spread and/or a reference signal, and improves decoding accuracy by adjusting the log likelihood ratio based on the inference result. With the recent rapid advancement of wired and wireless communication technologies and smart device-related technologies, high decoding accuracy for signals received by receivers in wireless communication systems is required. The higher the reliability of the log likelihood ratio (LLR), the more accurately the received signal can be decoded. However, as the channel estimation error for the estimated channel increases, the reliability of the log likelihood ratio may decrease, which can lead to a degradation in the performance of the wireless communication system. Generally, the channel estimation error can increase as the channel variation between subcarriers is large (frequency selectivity) or as the number of REs (Resource Elements) to which the reference signal is assigned is small. Therefore, a method is required to improve decoding performance by inferring the channel estimation error based on the channel variation and/or the reference signal and adjusting the log likelihood ratio. FIG. 1 is a block diagram showing a wireless communication system according to an exemplary embodiment of the present disclosure. FIG. 2 is a block diagram showing a wireless communication device according to an exemplary embodiment of the present disclosure. FIG. 3 is a block diagram showing an LLR adjustment module for adjusting the log likelihood ratio according to an exemplary embodiment of the present disclosure. FIG. 4 is a graph for illustrating frequency selectivity at the edge portion of a PRG according to an exemplary embodiment of the present disclosure. FIG. 5 is a graph for explaining MSE at the edge portion of a PRG according to an exemplary embodiment of the present disclosure. Figure 6 is a diagram illustrating the basic structure of the time-frequency domain, which is a wireless resource area in a wireless communication system. FIG. 7 is a diagram illustrating channel estimation of a data signal according to a reference signal according to an exemplary embodiment of the present disclosure. FIG. 8 is a flowchart illustrating a method of operation of a modem chip according to an exemplary embodiment of the present disclosure. FIG. 9 is a block diagram showing a wireless communication device according to an exemplary embodiment of the present disclosure. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. FIG. 1 is a block diagram showing a wireless communication system according to an exemplary embodiment of the present disclosure. Referring to FIG. 1, the communication system (10) may include a transmitter (100) and a receiver (200) that communicate wirelessly through a MIMO (Multiple Input and Multiple Output) channel (300). The system (10) may be any system including a MIMO channel (300). In some embodiments, the system (10) may be a wireless communication system such as a 5G (5th generation wireless) system, an LTE (Long Term Evolution) system, WiFi, etc., as a non-limiting example. In some embodiments, the system (10) may be a wired communication system such as a storage system, a network system, etc. Hereinafter, the system (10) will be described with reference primarily to a wireless communication system, but exemplary embodiments of the present disclosure are not limited thereto. For example, the transmitter (100) may be a base station or a component included in a base station. A base station may refer to a fixed station that communicates with a terminal and/or another base station, and may transmit and receive data and/or control information by communicating with a terminal and/or another base station. A base station may also be referred to as a Node B, eNB (evolved-Node B), BTS (Base Transceiver System), and AP (Access Point), etc. For example, the receiver (200) may be a terminal or a component provided in the terminal. The terminal may refer to various devices that are wireless communication devices capable of communicating with the transmitter (100) to transmit and receive data and/or control information. For example, the terminal may be referred to as User Equipment, MS (Mobile Station), MT (Mobile Terminal), UT (User Terminal), SS (Subscribe Station), wireless device, portable device, etc. A wireless communication network between a transmitter (100) and a receiver (200) can support multiple users communicating by sharing available network resources. For example, information can be transmitted in vari