Multiband OFDM Interleaving Circuit for Collision Mitigation
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Solution Overview
Problem
Conventional multiband OFDM transceivers experience performance degradation due to correlations between tones and sub-carriers, leading to inefficient data transmission in scenarios with collocated wireless networks, where collisions and interference reduce bit rate and throughput.
Innovation Solution
An interleaving circuit with a symbol interleaving unit, intra-symbol tone interleaving unit, and cyclic shift unit is introduced, which permutes bits across OFDM symbols and tones, and applies cyclic shifts based on a shift value changed between symbols, enhancing frequency and time diversity to improve data transmission performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional OFDM transmission is used in multiband transceivers, then the system structure is simple, but performance degrades due to correlations between tones and sub-carriers in collocated wireless networks
Solution Approach 1:
The interleaving circuit segments the encoded bitstream into multiple groups and permutes these groups across different OFDM symbols and sub-carriers. This segmentation breaks the correlation between adjacent bits and distributes them across diverse frequency and time resources, improving reliability in multiband OFDM transmission.
Solution Approach 2:
The patent applies interleaving in multiple dimensions: across different OFDM symbols (time dimension) and across different sub-carriers (frequency dimension). This multi-dimensional approach effectively breaks correlations by distributing bits across both time and frequency domains, resolving the performance degradation issue.
2Productivity
If bits are transmitted sequentially across OFDM symbols without interleaving, then the transmission process is simple, but collisions and interference reduce bit rate and throughput
Solution Approach 1:
The interleaving circuit performs preliminary permutation of bit groups across different OFDM symbols and sub-carriers before transmission. This preliminary action ensures that bits are already distributed across diverse resources when transmission begins, preventing the impact of collisions and interference on sequential bit streams and thereby improving bit rate and throughput.
3Productivity
If there are correlations between tones and sub-carriers, then the modulation process is straightforward, but data transmission efficiency decreases in scenarios with collocated wireless networks
Solution Approach 1:
The interleaving circuit dynamically permutes bit groups across different OFDM symbols and sub-carrier positions. This dynamic distribution adapts the bit placement to exploit frequency and time diversity, effectively combating the negative effects of correlations between tones and sub-carriers in collocated wireless networks and improving data transmission efficiency.
Data Source
AI summary
Interleaving circuit for a multiband OFDM (orthogonal frequency division multiplexing) transceiver of a ultra wide band wireless personal access network transmitting OFDM modulated symbols, wherein each OFDM symbol consists of a predetermined number (NCBPS) of encoded bits,said interleaving circuit comprisinga symbol interleaving unit which receives an input bitstream of encoded bits and permutes adjacent bits of said input bitstream across different OFDM symbols;an intra-symbol tone interleaving unit which receives the bits permuted by said symbol interleaving unit and permutes adjacent bits of each OFDM symbol across uncorrelated data sub-carriers; andan intra-symbol cyclic shift unit which shifts cyclically NCBPS bits of each OFDM symbol in response to a shift value (K) which is changed between adjacent OFDM symbols.