Programmable Transmitter Architecture for Multi-Mode Modulation
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Solution Overview
Problem
Existing transceiver architectures are limited to supporting either constant or non-constant envelope modulation schemes, requiring multiple chipsets and large component counts, which is inefficient and restricts bandwidth to a single communication standard, making them unsuitable for modern multi-mode wireless devices.
Innovation Solution
A programmable transmitter architecture that incorporates a single fractional-N synthesizer with digital controls, allowing switching between constant and non-constant envelope modulation schemes by turning on/off component blocks, enabling wide band, multi-mode operation across various communication standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate chipsets are used for constant and non-constant envelope modulation schemes, then each modulation type can be supported with optimized performance, but the device complexity and component count increase significantly
Solution Approach 1:
The patent implements a universal transmitter architecture where a single chipset can operate in both constant envelope mode (using PLL with VCO modulation) and non-constant envelope mode (using direct IQ modulation). The same core components including the fractional-N synthesizer, VCO, and modulator are reused across different modulation schemes through digital control, eliminating the need for separate chipsets and reducing overall device complexity while maintaining support for multiple modulation types
2Device complexity
If a single chipset is used for both constant and non-constant envelope modulation, then device complexity is reduced, but the ability to optimize performance for each specific modulation type is compromised
Solution Approach 1:
The patent employs dynamic reconfiguration of the transmitter architecture through digital control signals that can switch between different operational modes. The same physical components are dynamically allocated to different functions - the modulator can operate as either a PLL-based constant envelope modulator or a direct IQ modulator for non-constant envelope schemes, allowing optimized performance for each modulation type while using a single chipset
Solution Approach 2:
The system changes operational parameters through digital control to achieve different modulation modes. By adjusting control signals to the VCO, modulator, and synthesizer components, the transmitter can switch between constant and non-constant envelope modes, maintaining optimized performance for each scheme while using identical hardware with different configuration parameters
3Speed
If component blocks are continuously active to support all modulation modes, then switching between modes is fast, but power consumption increases
Solution Approach 1:
The patent implements periodic activation of component blocks based on the required modulation mode. Digital control signals selectively enable or disable specific components - for example, the direct IQ modulation path is activated only when non-constant envelope mode is required, while the PLL path is activated for constant envelope mode. This periodic on/off switching of components reduces power consumption while maintaining fast mode switching capability through pre-configured digital control
Data Source
AI summary
Transmitter architectures designed to accommodate both constant and non-constant of envelope modulation schemes and capable of providing local oscillator carrier frequencies within any one of numerous desired frequency bands, thus allowing compliance with many different communication standards. One example of a programmable frequency synthesizer includes a plurality of transmitter components and a microcontroller coupled to the frequency synthesizer and to the plurality of transmitter components. The microcontroller is adapted to provide a frequency control signal to the frequency synthesizer to control a frequency of the local oscillator carrier frequency. In addition, the microcontroller is also adapted to provide digital control signals to at least some of the plurality of transmitter components to turn on and off different ones of the plurality of transmitter components based on an operating mode of the transmitter, such that the transmitter can accommodate both constant envelope modulation and non-constant envelope modulation schemes.