simonwsw / deep-soli

Gesture Recognition Using Neural Networks with Google's Project Soli Sensor
MIT License
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Question: Understanding Ch #18

Open nyjinlee opened 7 years ago

nyjinlee commented 7 years ago

According to what I understand, each SoliData(###.h5) is transformed into 4 channels of images. However, in the network, it seems to be using only a single ch, which is the channel number assigned in main.lua. As I changed the assigned ch to 0, 2, 3 in main.lua the evaluation accuracy changes to 0.66988, 0.581660, 0.581513. Since 4 images(of channel 0~3) express a single data from SoliData, wouldn't all 4 channels be considered in training and evaluation process? If not, I am curious about what does each channel is indicating, and whether all 4 channels were used for training the network. Also, as implemented in ImageSeq:getImage(f) in imageseq.lua, is "datach" the number of consecutive RDI frames of the same channel that is stacked to form a part of input? It would be a great help if you help me with the confusion made by channels.

simonwsw commented 7 years ago

The four channel data comes from the Soli SDK, you can probably get more signal processing information from the Google Soli team. In our experiment setup, we use only one channel as the correlation between multi-channel doesn't help much with the accuracy - that is to say the same single channel setup is used across all the training and testing experiments.

datach is the number of the consecutive RDI frames of the same channel. It's a different concept comparison to the number of channels of a single frame.

JasperSrrzn commented 6 years ago

@nyjinlee. Did you already find what the different channels mean? I found a paper in which they mention something about the channels, but it is still not clear.

http://www.ivanpoupyrev.com/wp-content/uploads/2017/01/siggraph_final.pdf

rohanghige commented 5 years ago

What do those 4 channels (index 0 to 3) mean? Can you provide some paper link? Does each channel refer to Tx-Rx pair reception? How many Tx-Rx virtual antennas exist on the Deep-soli chip?