ePDCCH Scrambling Sequence Generation for Multiple Modulation Modes
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Solution Overview
Problem
In LTE Rel-11, the varying modulation modes of the enhanced physical downlink control channel (ePDCCH) make it difficult to determine the start position of scrambling sequences, preventing effective scrambling and descrambling, which limits system throughput and PDCCH capacity.
Innovation Solution
A method is introduced to generate scrambling sequences based on the index number and modulation mode of control channel elements, enabling scrambling and descrambling in multiple modulation modes by using specific long sequences and adjusting sequence lengths according to the modulation modes used by each control channel element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple modulation modes (QPSK, 16QAM, 64QAM) are used for ePDCCH to increase system throughput, then the PDCCH capacity increases, but the start position of scrambling sequences cannot be determined, preventing effective scrambling and descrambling
Solution Approach 1:
The patent changes the parameters used for scrambling sequence generation by introducing a new formula that incorporates both the eCCE index and modulation mode information. This allows the scrambling sequence start position to be dynamically adjusted based on the specific modulation mode being used, enabling proper scrambling extraction despite varying data lengths across different modulation modes
Solution Approach 2:
The patent performs preliminary determination of the scrambling sequence start position by calculating it in advance based on the eCCE index and expected modulation mode. This preliminary calculation enables the receiving end to properly extract and descramble the scrambling sequence before actual data reception, resolving the timing and positioning issues that would otherwise prevent effective descrambling
Data Source
AI summary
A method for processing physical downlink control channel data, a transmitting end, and a user equipment are provided and relate to the field of communications. According to the embodiment of the application a scrambling sequence in multiple modulation modes can be extracted, so that scrambling and descrambling are performed on physical downlink control channel data in multiple modulation modes. The method includes: generating a scrambling sequence corresponding to a control channel element according to an index number of the control channel element and/or a modulation mode used by the control channel element; performing scrambling on physical downlink control channel data by using the scrambling sequence; and sending the scrambled physical downlink control channel data to a user equipment. The embodiments of the present application are used to perform scrambling and descrambling on physical downlink control channel data.