Orthogonal Pilot Sequences for MIMO Antenna Port Differentiation
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Solution Overview
Problem
In MIMO wireless communication systems, the increasing number of transmit antennas leads to a waste of time-frequency resources due to the need for distinct time-frequency points for each antenna, reducing spectral efficiency and throughput.
Innovation Solution
The use of orthogonal pilot sequences allows multiple transmit antennas to share the same pilot mappings, reducing the time-frequency resources required for pilot sequence transmission by differentiating antennas through code division orthogonality rather than time-frequency orthogonality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If distinct time-frequency points are used for each transmit antenna to differentiate antenna ports, then antenna port identification is achieved, but time-frequency resources are wasted and spectral efficiency decreases
Solution Approach 1:
Multiple transmit antennas share the same time-frequency resources by merging their pilot sequence transmissions. Instead of assigning exclusive time-frequency points to each antenna, the patent combines multiple orthogonal pilot sequences transmitted simultaneously in the same time-frequency slot, enabling resource sharing while maintaining antenna differentiation through code division orthogonality
Solution Approach 2:
The patent changes the differentiation parameter from time-frequency domain to code domain. Instead of using different time-frequency points (temporal/spectral parameters), the system uses different orthogonal pilot sequences (code parameters) to differentiate antennas, allowing multiple antennas to occupy the same time-frequency resources
2Reliability
If time-frequency orthogonality is used to differentiate transmit antenna ports, then antenna identification is achieved, but the quantity of time-frequency resources increases linearly with the number of antennas
Solution Approach 1:
The patent introduces orthogonal pilot sequences as an intermediary mechanism to enable antenna differentiation without consuming additional time-frequency resources. These pilot sequences act as a mediating code layer that allows multiple antennas to be distinguished through code division rather than through exclusive time-frequency allocation
Solution Approach 2:
The patent adds a code dimension to the existing time-frequency resource allocation. By introducing orthogonal pilot sequences as a third dimension (code domain), the system can differentiate multiple antennas without expanding the time-frequency resource space, effectively utilizing multiple dimensions for differentiation
3Power
If more transmit antennas are added to increase MIMO capacity, then channel capacity improves, but time-frequency resource waste increases due to dedicated pilot sequences for each antenna
Solution Approach 1:
The patent makes the time-frequency resources universal by allowing multiple antennas to share the same resources. The orthogonal pilot sequences enable a single time-frequency slot to serve multiple antennas simultaneously, transforming exclusive resources into shared resources that support increased MIMO capacity without proportional resource consumption
Data Source
AI summary
Embodiments of the present disclosure provide methods and devices for inserting and extracting a pilot sequence according to a pilot mapping indicating a location for inserting the pilot sequence in a plurality of time-frequency resources. One example method includes inserting, by a transmitter according to pilot mappings corresponding to Nt transmit antenna ports by using Nt orthogonal pilot sequences that are different from each other, a pilot sequence corresponding to each of the transmit antenna ports into OFDM symbols that are included in the pilot mapping corresponding to the transmit antenna port. There is a one-to-one correspondence between the Nt pilot sequences and the Nt transmit antenna ports of the transmitter, where Nt is a positive integer greater than or equal to 2. The pilot mappings corresponding to the transmit antenna ports are the same among the Nt transmit antenna ports.