OFDM Transmitter Tone Interleaver for Uncompressed Video
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Solution Overview
Problem
Current wireless technologies lack the capability to transmit uncompressed high definition video signals effectively due to bandwidth limitations and interference issues, leading to data loss and reduced picture quality during transmission.
Innovation Solution
A wireless communication system utilizing a transmitter with a scrambler, forward error correction subsystem, interleaver, mapper, inverse fast Fourier transform subsystem, cyclic prefix adder, symbol shaping module, and up-converter to support high-rate unicast transmission over directional beams, along with a low-rate channel for control frames and omni-directional data, ensuring error correction and robust data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If uncompressed HD video signals are transmitted wirelessly, then transmission bandwidth requirement is high, but wireless channels suffer interference and data loss
Solution Approach 1:
The patent segments the video data into multiple blocks and distributes them across multiple OFDM symbols and sub-carriers. This segmentation allows the system to transmit high-bitrate uncompressed HD video while spreading the data over time and frequency, thereby reducing the impact of interference and enabling error correction.
Solution Approach 2:
The patent introduces an interleaver as an intermediary component that rearranges the data sequence before transmission. The interleaver acts as a mediator between the high-rate data stream and the wireless channel, redistributing data to protect against burst errors and interference while maintaining the high bandwidth requirement for uncompressed HD video.
2Productivity
If conventional compression is used to reduce bandwidth, then transmission bandwidth is reduced, but data loss occurs and picture quality deteriorates
Solution Approach 1:
The patent extracts the error correction and interference protection functions from the compression process. Instead of relying on compression to reduce bandwidth, the system transmits uncompressed HD video at high bandwidth and uses OFDM with interleaving and error correction to protect against wireless channel errors, thereby avoiding the picture quality degradation associated with compression.
Solution Approach 2:
The patent changes the transmission parameter from compressed low-bitrate to uncompressed high-bitrate. By using OFDM modulation and forward error correction, the system can accommodate the high bandwidth requirement of uncompressed HD video while maintaining reliability, thus changing the approach from bandwidth-efficient compression to quality-preserving high-bandrate transmission with protective measures.
3Adaptability or versatility
If multiple devices are connected to wireless network, then network functionality is enhanced, but interference increases and bandwidth is insufficient for uncompressed HD signals
Solution Approach 1:
The patent transitions from traditional time-division or frequency-division multiplexing to OFDM, which utilizes a two-dimensional frequency-time grid. This dimensional change allows multiple devices to share the wireless spectrum more efficiently by assigning different sub-carrier combinations, thereby supporting network versatility while reducing mutual interference.
Solution Approach 2:
The patent segments the available bandwidth into multiple orthogonal sub-carriers, each carrying a portion of the data stream. This frequency-domain segmentation allows multiple devices to be served simultaneously by assigning different sets of sub-carriers, thereby enhancing network adaptability while minimizing interference through orthogonal separation.
Data Source
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AI summary
A system and a method of using fast Fourier transform (FFT) based tone interleaver for OFDM are disclosed. One embodiment of the system includes an OFDM transmitter, which includes an inverse fast Fourier transform (IFFT) subsystem. The IFFT subsystem includes a bit-reversal (or quarternary-digit reversal depending on implementation) module followed by a butterfly operator. The bit-reversal (or quarternary-digit reversal) module output is connected to the butterfly operator input. The OFDM transmitter further includes a tone interleaver having an input and an output. The symbol interleaver output is connected to the bit reversal (or quarternary-digit reversal) module input. The tone interleaver is configured to rearrange the input symbol sequence such that the symbol sequence input to the tone interleaver input is the same as the symbol sequence input to the butterfly operator input.