OFDM Receiving Apparatus Short Frame Pilot Interpolation
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Solution Overview
Problem
In OFDM-based terrestrial digital broadcasting systems, such as DVB-T2, the short frame length results in insufficient Scattered Pilots (SPs) for effective time interpolation, leading to challenges in accurately estimating transmission paths, especially in multipath channels.
Innovation Solution
A receiving apparatus and method that includes a short frame determining portion to identify short frames and employ P2 symbol pilots for time interpolation, ensuring precise transmission path estimation even in frames with limited SPs by using P2 symbol pilots instead of missing SPs, and performing frequency interpolation to compensate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the frame length is shortened to increase transmission efficiency, then the transmission speed is improved, but the number of Scattered Pilots available for time interpolation becomes insufficient
Solution Approach 1:
The patent combines P2 symbol pilots with Scattered Pilots for time interpolation. Specifically, when SPs are insufficient in short frames, the receiving apparatus uses P2 symbol pilots (which are normally used for frequency interpolation) to supplement the time interpolation process, merging two previously separate pilot functions to resolve the contradiction between short frame length and sufficient pilot availability
Solution Approach 2:
The patent makes P2 symbol pilots serve multiple functions. Normally P2 pilots are used only for frequency interpolation, but the invention enables them to also perform time interpolation when SPs are insufficient, giving this pilot type universal applicability across different interpolation needs and frame conditions
2Productivity
If the frame length is shortened, then the transmission efficiency is improved, but the accuracy of transmission path estimation deteriorates
Solution Approach 1:
The patent merges P2 symbol pilot data with SP data to maintain accurate transmission path estimation in short frames. By combining these pilot sources and using them together for time interpolation, the system preserves estimation accuracy despite the reduced frame length and fewer available SPs
Solution Approach 2:
The patent dynamically changes the interpolation parameters based on frame length. When short frames are detected, the system switches from using only SPs to using both P2 pilots and SPs, effectively changing the interpolation method parameters to adapt to the short frame condition and maintain estimation accuracy
Data Source
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AI summary
Disclosed herein is a receiving apparatus for receiving an orthogonal frequency division multiplexing signal, namely, OFDM signal having a frame having one frame length of a plurality of patterns, including: an acquiring section configured to acquire information on a preamble signal from the OFDM signal transmitted from a transmitting apparatus in accordance with an OFDM system; a frame determining section configured to determine whether or not the one frame length is short in the frame based on the information on the preamble signal acquired from the acquiring section; and a time interpolating section configured to obtain transmission path characteristics by comparing a pilot contained in the preamble signal and a known pilot corresponding to the pilot in a phase of transmission with each other when the frame determining section determines that the one frame length is short in the frame, and interpolate a data portion in a time direction based on the transmission path characteristics thus obtained.