Dual Carrier Index Modulation for High Data Rate Wireless
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Solution Overview
Problem
Existing wireless communication technologies, such as OFDM, face challenges in increasing data rate while maintaining high error performance, as methods like DCM reduce data rate to improve reliability, which is undesirable in future high-data-rate wireless communication standards.
Innovation Solution
The method involves dividing groups of bits into subgroups and selecting sequences of modulation schemes to map bits onto subcarriers, using index modulation to increase data rate while maintaining error performance, by employing multiple modulation schemes and performing maximum likelihood estimation for reliable transmission and reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Dual Carrier Modulation (DCM) is used to improve reliability, then error performance is improved, but data rate is reduced by half
Solution Approach 1:
The bit stream is segmented into multiple groups of p bits, where each group is divided into a first subgroup of p1 bits and a second subgroup of p2 bits. This segmentation allows different portions of data to be processed through different modulation schemes, enabling both reliable transmission and higher data rates simultaneously.
Solution Approach 2:
The patent introduces index modulation by selecting sequences of modulation schemes from a plurality of predetermined sequences. This adds a new dimension to the transmission system where the selection of modulation scheme sequences carries additional information (p1 bits), effectively doubling the data rate compared to traditional DCM while maintaining error performance.
2Productivity
If higher data rate is achieved by increasing modulation order, then productivity is improved, but reliability deteriorates due to higher error rate
Solution Approach 1:
The patent dynamically changes modulation parameters by selecting from multiple predetermined sequences of modulation schemes. Each sequence contains R modulation schemes that can be selected based on the p1 bits, allowing the system to adapt the modulation order and type to achieve both high data rate and maintain reliability through diversity.
Solution Approach 2:
The transmission system uses a composite approach combining multiple modulation schemes (e.g., BPSK, QPSK, 16-QAM, 64-QAM) within a single transmission framework. This composite modulation structure allows the system to achieve high data rates through higher-order modulations while maintaining reliability through the diversity provided by multiple sequences and the index modulation component.
Data Source
AI summary
Methods and techniques are described for increasing data rate at a high error performance in wireless transmission. A plurality of groups of p bits, wherein p is an integer greater than 1, is obtained. A transmission signal is generated, which includes, for a group of p bits dividing the group of p bits into a first subgroup of p1 bits and a second subgroup of p2 bits, wherein p1 and p2 are integers greater than zero. Based on the p1 bits, a sequence of modulation schemes is selected from a plurality of predetermined sequences of modulation schemes. The predetermined sequences are mutually different, and each of the predetermined sequences has length R, wherein R is an integer greater than 1. The p2 bits onto R subcarriers are mapped respectively by means of the R modulation schemes of the selected sequence. Finally, the generated transmission signal is transmitted.