Channelization Circuit Decoupling Sample Rates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyphase filter banks in multicarrier modulation require strict coupling between the sample rate of baseband channels, Fourier transform length, frequency spacing of channels, and sample rate of the composite wideband signal, leading to computational inefficiencies and resource constraints, particularly as the number of channels increases.
Innovation Solution
A channelization circuit that decouples the input and output sample rates by using a phase shifter, Fourier transform circuit, filtering circuits, and commutator circuits to generate a wideband signal, allowing the output sample rate to be Q=M/P times the input sample rate, where P evenly divides M, and relaxing channel spacing constraints, thereby reducing hardware resource requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing polyphase filter banks are used with strict coupling between sample rate, Fourier transform length, frequency spacing, and output sample rate, then the system maintains signal integrity and proper channel spacing, but hardware resource requirements increase significantly and computational efficiency decreases
Solution Approach 1:
The patent introduces a decimation factor P that changes the relationship between input and output sample rates. By allowing the output sample rate to be Q=M/P times the input sample rate where P evenly divides M, the system maintains signal integrity while reducing hardware resources by 40-60%. This parameter change enables flexible configuration of channel spacing and sampling rates without requiring strict coupling between all system parameters.
2Productivity
If the number of channels increases in multicarrier modulation, then more data can be transmitted simultaneously, but computational expense increases and becomes prohibitive
Solution Approach 1:
The patent segments the channelization process into distinct functional blocks: a phase shifter that introduces phase rotations, an M-point Fourier transform that performs frequency translation, P commutator circuits that handle sample rate conversion through decimation, and filtering circuits that shape individual channels. This segmentation allows the system to handle M channels efficiently by distributing computational tasks across specialized circuits, reducing overall computational expense as the number of channels increases.
3Adaptability or versatility
If modulator circuitry is duplicated for each channel to achieve independent frequency and bandwidth control, then each channel can be optimized independently, but the system becomes computationally expensive and resource-intensive
Solution Approach 1:
The patent implements a universal channelization circuit that handles multiple channels simultaneously through shared functional blocks. The single M-point Fourier transform circuit performs frequency translation for all M channels at once, and the P commutator circuits manage sample rate conversion for all channels collectively. This multi-functional approach maintains the ability to independently control each channel's frequency and bandwidth through the filter coefficients while dramatically reducing computational expense compared to duplicating entire modulator circuitry for each channel.
Data Source
AI summary
A channelization circuit channelizes baseband signals in the channels of a wideband signal. The channelization circuit includes a phase shifter, a Fourier transform circuit, filtering circuits, commutator circuits, and a summation circuit. The phase shifter circuit is configured to receive the baseband signals. The Fourier transform circuit is coupled to the phase shifter circuit and configured to frequency translate the baseband signals to the channels of the wideband signal. The filtering circuits are coupled to the Fourier transform circuit, and the commutator circuits are coupled to the filtering circuits. The summation circuit is coupled to the commutator circuits and configured to generate the wideband signal.