PPDU Transmit Chain Mapping for mmWave Multi-User MIMO
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems in the millimeter-wave band face challenges in efficiently transmitting high-speed data, particularly in achieving multi-gigabit data rates over directional links, and supporting multiple user MIMO communications, which are essential for next-generation wireless networks like 5G and beyond.
Innovation Solution
The implementation of an Enhanced Directional Multi-Gigabit (EDMG) Physical Layer Protocol Data Unit (PPDU) format, which includes specific fields and training sequences, and a transmitter architecture that uses channel bonding, cyclic shift diversity, and orthogonal frequency-division multiplexing (OFDM) interleaving to enhance data transmission rates and support multi-user MIMO communications over mmWave frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional wireless communication systems are used in millimeter-wave band, then existing infrastructure can be maintained, but data transmission rates are limited and cannot achieve multi-gigabit speeds
Solution Approach 1:
The PPDU is segmented into multiple fields (L-STF, L-CEF, L-header, EDMG-Header-A, EDMG-STF, EDMG-CEF, EDMG-Header-B, data field) with specific functions. Each field is processed and transmitted separately through dedicated circuitry, enabling high-speed transmission while managing complexity through functional division.
Solution Approach 2:
The patent introduces channel bonding that combines multiple 2.16 GHz channels to form wider channels (4.32 GHz, 6.48 GHz, 8.64 GHz), adding a frequency dimension to increase data rates. Additionally, MIMO technology adds spatial dimensions by using multiple transmit and receive antennas simultaneously.
2Productivity
If channel bonding and MIMO are implemented to increase data rates, then multi-gigabit transmission is achieved, but the transmitter and receiver architecture becomes more complex
Solution Approach 1:
The transmitter architecture is designed to universally support multiple transmission modes including single-channel and bonded-channel operations, SISO and MIMO configurations. The same hardware infrastructure can adapt to different data rates and channel conditions without requiring completely separate systems.
Solution Approach 2:
The system dynamically selects channel bonding configurations (2x2.16 GHz, 3x2.16 GHz, 4x2.16 GHz) and MIMO parameters based on channel conditions and data rate requirements. This dynamic adaptation allows the system to optimize performance while managing complexity through conditional operation rather than fixed maximum-capability hardware.
3Productivity
If directional links are used to achieve high-speed data access, then data transmission rate increases, but the system becomes more sensitive to alignment and positioning
Solution Approach 1:
The patent implements preliminary beam training using STF and CEF fields before actual data transmission. These training sequences enable the receiver to estimate channel conditions and determine optimal beam directions in advance, ensuring reliable directional links are established before high-rate data transmission begins.
Solution Approach 2:
The system uses feedback from channel estimation and beam training processes to continuously adjust beamforming weights and directional parameters. This closed-loop control maintains link reliability by adapting to changes in alignment and positioning while sustaining high data transmission rates.
Data Source
AI summary
An apparatus of a transmitter may include, for example, a Golay builder to build modulated Golay sequences for at least a non-EDMG Short Training Field (L-STF), and a non-EDMG Channel Estimation Field (L-CEF) of a PPDU; a scrambler to generate scrambled bits by scrambling bits of a non-EDMG header (L-header) and a data field of the PPDU; an encoder to encode the scrambled bits into encoded bits according to a low-density parity-check (LDPC) code; a constellation mapper to map the encoded bits into a stream of constellation points according to a constellation scheme; a spreader to spread the stream of constellation points according to a Golay sequence; and a transmit chain mapper to map a bit stream output from the Golay builder and the spreader to a plurality of transmit chains by applying a spatial expansion with relative cyclic shift over the plurality of transmit chains.