Wireless Device Frequency Band Determination via DC Subcarrier Offset
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Solution Overview
Problem
In 4G LTE communication systems, wireless communication devices face challenges in determining the starting frequency of a frequency band when the direct current (DC) subcarrier is not centered, as existing methods assume the DC subcarrier is centered, leading to inaccuracies in calculating the frequency band.
Innovation Solution
The method involves identifying a carrier frequency, determining the associated DC subcarrier, synchronizing with it to obtain channel information including a channel size and DC subcarrier offset, and processing this information to calculate the starting frequency of the frequency band, even if the DC subcarrier is not centered.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the existing method assumes the DC subcarrier is centered in the frequency band, then the calculation process is simplified, but the measurement precision of the starting frequency is degraded when the DC subcarrier is not actually centered
Solution Approach 1:
The patent changes the parameter assumption from 'DC subcarrier is centered' to 'DC subcarrier may be offset by K subcarriers'. By introducing the offset parameter K and using the relationship between the first uplink channel's resource blocks and the DC subcarrier position, the system can calculate the actual starting frequency of the frequency band even when the DC subcarrier is not centered, thus resolving the contradiction between calculation simplicity and measurement precision.
2Loss of time
If the DC subcarrier offset is not considered, then the initial connectivity setup is faster, but the reliability of frequency band determination is reduced
Solution Approach 1:
The patent performs preliminary determination of the DC subcarrier offset K during the initial synchronization phase. By calculating the offset based on the first uplink channel's resource block allocation before actual data transmission begins, the system establishes accurate frequency band information in advance, ensuring both fast initial connectivity and reliable frequency band determination without compromising either aspect.
Data Source
AI summary
A wireless communication device to facilitate determination of frequency band information comprises a processing system and a wireless communication transceiver. The processing system is configured to identify a carrier frequency stored within the wireless communication device and determine a direct current (DC) subcarrier associated with the carrier frequency. The wireless communication transceiver is configured to synchronize with the DC subcarrier to obtain channel information, wherein the channel information comprises a channel size and a DC subcarrier offset. The processing system is configured to process the DC subcarrier with the DC subcarrier offset to determine a starting frequency of a frequency band associated with the carrier frequency.