FR2 Uplink 256-QAM MCS Mapping for Frequency-Specific EVM Compliance
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Solution Overview
Problem
The challenge of setting the Modulation and Coding Scheme (MCS) index for uplink signals in 256QAM transmission in FR2 is not adequately addressed, leading to potential exceedance of the reference Error Vector Magnitude (EVM) level.
Innovation Solution
The MCS index is set based on the carrier frequency to prevent uplink signals from exceeding the reference EVM level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the MCS index is set for uplink transmission in 256QAM on FR2, then the data transmission rate is improved, but the EVM level may exceed the reference value
Solution Approach 1:
The patent applies parameter changes by establishing a correspondence relationship between carrier frequency and MCS index. Different MCS indices are selected based on the operating carrier frequency (e.g., FR2-1 band vs. FR2-2 band), which adjusts the modulation and coding parameters to maintain EVM within the reference level while optimizing data transmission rate for each frequency range.
2Device complexity
If a unified MCS index is used for all FR2 bands, then the device complexity is reduced, but the EVM compliance cannot be ensured across different frequency bands
Solution Approach 1:
The patent applies local quality by defining frequency-band-specific MCS index mappings. Instead of using a single unified MCS table for all FR2 bands, the patent creates separate correspondence relationships for different FR2 sub-bands (FR2-1: 24.25-29.5GHz, FR2-2: 30-48GHz), allowing each local frequency region to have optimized MCS parameters that ensure EVM compliance while maintaining relatively simple configuration.
Data Source
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AI summary
One disclosure of the present specification provides a method by which a UE performs communication. The method comprises the steps of: receiving a CSI-RS from a base station; measuring a channel state on the basis of the CSI-RS; transmitting, to the base station, a CSI report including the channel state; receiving, from the base station, an MCS index on the basis of the CSI report; and transmitting, to the base station, an uplink signal in 256 QAM on the basis of the MCS index, wherein the MCS index is MCS#20, MCS#21 or MCS#22 on the basis of the uplink signal having a carrier frequency of 39 GHz, and the MCS index is MCS#20, MCS#21, MCS#22 or MCS#23 on the basis of the uplink signal having a carrier frequency of 29 GHz.