Bi-orthogonal filter design method and its design device

Abstract

The device for designing dual orthogonal filter (DOF) includes following parts and operations: transmission filter (TF) design device in use for designing TF by using traditional method; FFT device in use to calculate FFT to calculate frequency response; device for selecting target correlation function in use for selecting target cross power spectrum function (TCPSF), and aliasing the function sampled in 1 / Ts interval to obtain a constant; device for designing receiving filter carries out dividing TCPSF by frequency response of transmission filter in frequency domain (FD), or equivalent deconvolution operation in time domain (TD); adding window for the result, or equivalent convolution operation of window function in TD; inverse Fourier transforming the signal with window being added to TD, conjugated backout for the signal in TD so as to obtain impulse response in TD of DOF. Dual orthogonal nature between receiving filter and TF guarantees no loss on comm. system.

Description

technical field [0001] The invention relates to a design method of a bi-orthogonal filter and a design device thereof, in particular to a design method of a bi-orthogonal filter applied to a single carrier-frequency division multiple access system (SC-FDMA) and a design device thereof. Background technique [0002] The single-carrier-frequency-division multiple access system is a new type of frequency-division multiple access communication system that has not only the peak-to-average ratio of single-carrier communication power, but also has the characteristics of simple implementation of multi-carrier communication and flexible resource scheduling. It is mainly used in the uplink solution of broadband mobile communication, and supports frequency domain expansion technology, frequency domain equalization method and multi-user concurrent communication scenarios. In the single carrier-frequency division multiple access system, the entire broadband channel is divided into severa...

AI Technical Summary

Problems solved by technology

For the root-raised cosine roll-off filter, this requirement can be achieved by reducing the roll-off factor, but at the same time, as the roll-off factor decreases, the decay of the time-domain response of the root-raised cosine roll-off filter will be significantly slower

On the one hand, a longer time-domain pulse waveform will increase the truncation error of the filter, and on the other hand, it will greatly increase the processing complexity of the transmitter, which is especially unfavorable for uplink transmission.

Although Gaussian filtering is relatively concentrated in the time domain and has a short impulse response, its absolute bandwidth is much larger than that of the raised cosine filter, and it is difficult to meet the requirements of multi-user transmission for spectrum multiplexing

[0004] On the other hand, when the traditional root-raised cosine roll-off filter and Gaussian pulse shaping filter are applied to the uplink solution of the single carrier-frequency division multiple access system, there is a contradiction that the time domain and the frequency domain cannot be "gathered" at the same time

When the filter can meet the fast attenuation in the frequency domain, that is, to ensure the orthogonality of the sub-channels, it cannot have a shorter time-domain impulse response, which cannot be realized with a smaller-order FIR filter, and the operational complexity of the transmitter Very large; when the filter has a short time-domain response, the orthogonality between sub-channels cannot be well maintained in the frequency domain, resulting in a decrease in the spectrum utilization of the communication system

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