Base Station Masking Sequence for Control Channel Identification
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Solution Overview
Problem
Current wireless communication systems, such as 3GPP LTE and IEEE 802.16m, face challenges in efficiently identifying message types and managing address spaces for control channel information elements, particularly in masking cyclic redundancy checks (CRC) with varying identifier lengths and types.
Innovation Solution
A base station and subscriber station system that generates and uses a 4-bit masking sequence, where the three least significant bits of the prefix indicate the message type of the control channel information element, allowing for efficient masking and unmasking of CRCs, thereby extending address space without additional signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional CRC masking methods are used with varying identifier lengths, then flexibility in addressing different station types is achieved, but system complexity and signaling overhead increase
Solution Approach 1:
The patent changes the parameter of masking sequence length from variable (matching identifier length) to fixed (32 bits for all cases). This standardization simplifies the masking operation while maintaining the ability to address different station types through the fixed-length sequence, resolving the contradiction between adaptability and complexity
Solution Approach 2:
The fixed 32-bit masking sequence serves multiple functions: it masks CRC for different station types (unicast, multicast, broadcast), provides message type identification through specific bit patterns, and maintains backward compatibility. This multi-functionality eliminates the need for separate masking mechanisms for different identifier lengths
2Productivity
If fixed-length masking sequences are used, then processing efficiency is improved, but address space flexibility may be reduced
Solution Approach 1:
The fixed 32-bit masking sequence is segmented into functional parts: message type identification bits and station-specific identification bits. This segmentation allows the fixed-length sequence to efficiently indicate message types while simultaneously providing flexible addressing capability for different station types
Solution Approach 2:
The patent adds a new dimension to the masking sequence by incorporating message type identification functionality within the fixed 32-bit structure. This dimensional expansion allows the sequence to convey both message type and station identification information simultaneously, maintaining flexibility while improving processing efficiency
Data Source
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AI summary
A base station is provided. The base station includes a transmit path circuitry that generates a masking sequence to mask a cyclic redundancy check of a control channel information element. The masking sequence includes a 4-bit prefix. The three least significant bits of the 4-bit prefix indicate a message type of the control channel information element. A subscriber station is also provided. The subscriber station includes a receive path circuitry that determines a message type of a control channel information element using a three least significant bits of a 4-bit prefix of a masking sequence used to mask a cyclic redundancy check of the control channel information element.