Programmable Transmitter Modified Preamble for MIMO Compatibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in achieving high data throughput while being backward compatible with legacy devices and adjustable to different channel bandwidths, particularly in supporting MIMO communications that are detectable by legacy devices.
Innovation Solution
A programmable transmitter is designed to generate modified preambles for high data rate and mixed-mode transmissions, capable of operating in various wireless communication standards, including MIMO, by using multiple antennas and spatial encoding, and is adjustable to different channel bandwidths, ensuring compatibility with legacy devices through specific preamble formats and cyclic shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If MIMO communications are implemented to increase data throughput, then productivity is improved, but device complexity increases due to multiple antennas and spatial encoding requirements
Solution Approach 1:
The MIMO transmission is segmented into multiple spatial streams that are processed independently through the same OFDM modulation chain. Each spatial stream uses identical preamble structures but with different spatial encoding, allowing the system to achieve high throughput through parallel processing rather than complex integrated handling
Solution Approach 2:
The transmitter is designed with a universal OFDM modulation architecture that handles both single-stream and multi-stream transmissions using the same core components. The spatial encoder and multiple antennas provide MIMO functionality while the base OFDM structure remains unchanged, enabling the system to perform multiple functions (SISO and MIMO) with a single design
2Productivity
If modified preambles are used for high data rate transmissions, then productivity is improved, but ease of operation deteriorates due to compatibility requirements with legacy devices
Solution Approach 1:
The preamble structure uses local quality differentiation where the legacy prefix portion maintains traditional format for backward compatibility, while the Greenfield portion utilizes modified structures optimized for high data rate MIMO transmissions. This allows different parts of the same signal to serve different purposes with different quality requirements
Solution Approach 2:
The modified preamble embeds a legacy-compatible prefix structure within the overall transmission frame, which contains the new high-data-rate optimized Greenfield portion. The legacy devices can process the outer prefix structure while advanced devices can access the inner Greenfield content for enhanced performance
3Adaptability or versatility
If adjustable channel bandwidths are supported to increase versatility, then adaptability is improved, but device complexity increases due to reconfiguration requirements
Solution Approach 1:
The OFDM modulation parameters including channel bandwidth, subcarrier spacing, and IFFT size are designed to be dynamically adjustable through software control. This allows the transmitter to adapt to different channel conditions and standards requirements without hardware reconfiguration, achieving versatility through flexible parameter setting rather than fixed architecture
Data Source
AI summary
A programmable transmitter generates a frame preamble to train a receiver with respect to a communication link format that corresponds to a transmission mode wherein the transmission mode may comprise transmitting the communication link over one or more antennas. Generally, the invention includes generating a preamble with an arrangement that depends upon whether a Greenfield (high data rate) or mixed mode transmission is to occur and that depends upon a number of spatial streams that are to be generated. One format for high data rate transmission includes a short training sequence, a long training sequence and a signal field. The mixed mode transmission further includes a legacy prefix.