Alternating Real and Complex Modulation for Wireless Data Transmission
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Solution Overview
Problem
Existing wireless communication networks face inefficiencies with real and complex modulation techniques, as real modulation methods like ASK are power-inefficient and require accurate signal power measurement, while complex methods like QAM are susceptible to multipath interference.
Innovation Solution
A novel modulation technique that alternates between real and complex modulation branches, using amplitude shift keying (ASK) and quadrature amplitude modulation (QAM) respectively, with a signal dividing unit that adapts bit lengths and modulation schemes based on signal quality metrics, and employs time-division or frequency-division multiplexing for transmission, along with Wide Linear Zero Forcing (WLZF) and Successive Interference Cancellation (SIC) for demultiplexing and decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If real modulation (ASK) is used, then power efficiency is improved, but the receiver requires accurate signal power measurement capability
Solution Approach 1:
The bit sequence is divided into alternating first segments and second segments, where first segments are modulated using real modulation (ASK) and second segments using complex modulation (QAM). This segmentation allows the system to leverage the power efficiency of ASK while avoiding its drawbacks through alternating use of QAM.
Solution Approach 2:
Different modulation schemes are applied to different segments of the bit sequence based on local requirements. Real modulation is used for segments where power efficiency is critical, while complex modulation is used for segments where robustness against multipath interference is needed.
2Reliability
If complex modulation (QAM) is used, then signal power remains constant, but the receiver is highly susceptible to multipath interference
Solution Approach 1:
The bit sequence is segmented into alternating portions that use real and complex modulation respectively. This allows the system to switch between modulation types to avoid the multipath susceptibility of QAM when channel conditions are poor, while still utilizing QAM's constant envelope property when conditions permit.
Solution Approach 2:
The modulation scheme dynamically switches between real and complex modulation based on signal quality metrics. The signal dividing unit obtains a metric of signal quality and selects bit lengths and modulation schemes according to this metric, making the system adaptive to changing channel conditions.
3Productivity
If adaptive modulation based on signal quality is implemented, then system performance is improved, but device complexity increases
Solution Approach 1:
The signal dividing unit dynamically adjusts the bit lengths of first and second segments based on the obtained signal quality metric. This allows the system to optimize performance for current channel conditions while maintaining a structured approach to modulation switching.
Solution Approach 2:
The system changes modulation parameters (bit lengths, modulation scheme selection) based on signal quality metrics. Predefined modulation schemes are associated with different ranges of signal quality values, allowing adaptive optimization without requiring complex real-time decision logic.
Data Source
AI summary
Apparatus and methods are disclosed for transmitting and receiving data in a wireless communication network. Apparatus for transmitting data in a wireless communication network comprises a real modulation branch for modulating a first segment of a bit sequence to obtain a real modulated signal, a complex modulation branch for modulating a second segment of the bit sequence to obtain a complex modulated signal, a signal dividing unit configured to divide the bit sequence into a plurality of alternating first segments and second segments, and to send the first segments and the second segments to the real modulation branch and the complex modulation branch respectively, and a transmitter configured to transmit the real and complex modulated signals. Apparatus and methods are also disclosed for demultiplexing a plurality of data streams, using wide linear zero forcing with successive interference cancellation.