Multicarrier channelization and demodulation apparatus and method

摘要

A method of decoding a digitally encoded signal having plural channels includes sampling a transient portion of a master filter mask, storing matched filter coefficients obtained from the sampling, receiving the digitally encoded signal, channelizing the digitally encoded signal into the plural channels, and generating a channel matched filter mask for each one of the plural channels using a subset of the stored coefficients. The method also includes filtering each one of the plural channels, in the frequency domain, based on the channel matched filter mask generated for each of the plural channels. Also disclosed are related methods using a burst reconstruction buffer, per channel distortion equalization, channel estimation and activity monitoring, and noise floor estimation, as well as corresponding apparatuses.

主权项

1. A method of decoding a Time Division Multiple Access (TDMA) digitally encoded signal having plural channels and at least one channel in the plural channels having a different symbol rate than other channels in the plural channels, the method comprising:
generating, from the digitally encoded signal by a frequency domain channelizer, a sequence of overlapped Fast Fourier Transform (FFT) blocks each produced by an overlap-add or overlap-save convolution of a received analog signal; generating one channel data block for each of the plural channels from each overlapped FFT block, a size of each channel data block depending, in part, on the symbol rate of the corresponding channel, and a number of samples per symbol of the corresponding channel; storing each of the plural channel data blocks in a corresponding independent channel buffer of a burst reconstruction buffer, the burst reconstruction buffer including an independent channel buffer for each of the plural channels and a counter for each of the independent channel buffers, each counter counting a number of samples that are currently stored in a corresponding independent channel buffer; selecting one of the independent channel buffers when a counted number of samples by the corresponding counter exceeds a value that corresponds to a length of a complete TDMA burst for the corresponding channel; outputting, as a complete TDMA burst, the plurality of channel data blocks from the selected one of the independent channel buffers to a TDMA demodulator; and demodulating the complete TDMA burst of the digitally encoded signal at the TDMA demodulator from the plurality of channel data blocks outputted from the selected one of the independent channel buffers.