DMRS Sequence Mapping for MTC Sub-PRB Transmission
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Solution Overview
Problem
Current methods are inefficient in configuring and transmitting Demodulation Reference Signals (DMRS) for frequency domain resources smaller than a Physical Resource Block (PRB) in Machine Type Communication (MTC) devices, which limits their ability to efficiently transmit uplink data using reduced bandwidth.
Innovation Solution
A method for selecting and transmitting DMRS sequences based on group hopping numbers and allocation region information for sub-PRBs with fewer than 12 subcarriers, allowing MTC devices to efficiently demodulate uplink data by mapping selected sequences to specific subcarriers, and configuring DMRS sequences independently to avoid interference with existing signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If MTC devices use reduced bandwidth (sub-PRB) for transmission, then manufacturing cost and device complexity are reduced, but DMRS configuration efficiency deteriorates
Solution Approach 1:
The patent changes the parameters of DMRS configuration by introducing sub-PRB allocation with flexible numbers of subcarriers (M < 12), adjusting sequence length, and modifying mapping patterns to suit reduced bandwidth operations, thereby maintaining configuration efficiency while using reduced bandwidth
Solution Approach 2:
The patent segments the traditional PRB into smaller sub-PRB units with M subcarriers (where M < 12), allowing MTC devices to allocate DMRS sequences to these segmented resources efficiently, thus resolving the contradiction between reduced bandwidth usage and configuration efficiency
2Productivity
If DMRS sequences are mapped to sub-PRB with M subcarriers (M < 12), then uplink data transmission efficiency is improved, but sequence selection complexity increases
Solution Approach 1:
The patent changes the sequence selection mechanism by introducing group hopping parameters and allocation region information as selection criteria, transforming the complex sequence selection into a structured process based on these parameters, thus reducing selection complexity while maintaining transmission efficiency
Solution Approach 2:
The patent performs preliminary configuration of DMRS sequences based on group hopping numbers and allocation region information before actual data transmission, preparing the sequence selection in advance according to predetermined parameters, which simplifies the real-time transmission process
Data Source
AI summary
One embodiment of the present specification provides a method by which a machine type communication (MTC) device configured to operate only in some bands among the system bands of a cell transmits a demodulation reference signal (DMRS) for the demodulation of uplink data. The method can comprise the steps of: selecting any one DMRS sequence among a plurality of sets of DMRS sequences having a length M according to a group hopping number and allocation area information of a sub-physical resource block (PRB), when an uplink signal is transmitted through the sub-PRB including the M number of subcarriers which is less than twelve subcarriers; and mapping the selected DMRS sequence on the M number of subcarriers of the sub-PRB, and transmitting the same.