Communication Device Scrambled CRC for Latency Reduction
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Solution Overview
Problem
In LTE systems, the latency introduced by the need for user equipment (UE) to check for scheduling on a physical downlink control channel (PDCCH) before transmitting or receiving data hampers efficient data transmission and reception.
Innovation Solution
A communication device that generates and transmits a transport block (TB) with a scrambled cyclic redundancy check (CRC) using a cell radio network temporary identifier (C-RNTI), allowing for efficient data transmission on orthogonal frequency division multiplexing (OFDM) symbols or resource blocks, thereby reducing latency by eliminating the need for PDCCH scheduling checks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE checks for scheduling on PDCCH before transmitting or receiving data, then the system maintains proper scheduling control, but transmission latency increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring uplink resources and transmitting data directly without waiting for PDCCH scheduling checks. The UE is provided with uplink grant information in advance through RRC signaling or random access response, allowing it to transmit data immediately when data is available, thus eliminating the latency caused by checking PDCCH before each transmission.
Solution Approach 2:
The patent extracts the scheduling check step from the traditional transmission process. By separating the resource allocation phase (where resources are pre-configured) from the data transmission phase, the system removes the need for UE to check PDCCH before transmission, while still maintaining overall scheduling control through the pre-configured resource allocation.
2Loss of time
If direct data transmission without PDCCH scheduling checks is implemented, then transmission latency is reduced, but system complexity increases
Solution Approach 1:
The patent uses preliminary action to resolve this contradiction by pre-configuring all necessary transmission parameters (resources, power, modulation) through RRC signaling or random access response before data transmission. This allows the UE to transmit data directly without complex real-time scheduling checks, reducing latency while keeping system complexity manageable through advance configuration.
3Productivity
If uplink resources are pre-configured for direct transmission, then transmission efficiency improves, but resource allocation flexibility decreases
Solution Approach 1:
The patent applies dynamics by allowing the system to switch between different transmission modes. The UE can use pre-configured uplink resources for direct transmission when data is available, while the network retains the ability to send PDCCH scheduling commands when dynamic resource allocation is needed. This dynamic approach maintains transmission efficiency for urgent data while preserving resource allocation flexibility for varying traffic conditions.
Data Source
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AI summary
A first communication device of handling communication with a second communication device comprises a storage unit for storing instructions and a processing circuit coupled to the storage unit. The processing circuit is configured to execute the instructions stored in the storage unit. The instructions comprise generating a transport block (TB); generating a first cyclic redundancy check (CRC) according to the TB; scrambling the first CRC with a first identifier to a first scrambled CRC, wherein the first identifier is known by the first and second communication devices; and performing a transmission of the TB and the first scrambled CRC on at least one first subcarrier in at least one first consecutive orthogonal frequency division multiplexing (OFDM) symbol, to the second communication device.