I processed a tiff DEM (I call it A) in MATLAB and the result (I call it B) loses its georeferencing information. Now I imported B in the ArcMap again and need to overlay it on A (georeferenced) in ArcMap. So they both have the same number of rows and columns. I just want to georeference B exactly the same as A. It should be something quite easy forward like just copying the georeferencing information of A to B (two rasters with the exact same size). But I couldn't find any help through this.
One option would be to use the Esri world file. The world file is basically a text file that contains the georeferencing information for a raster. You can create a world file for raster (A) and apply it to raster (B) simply by renaming the world file to match the name of raster (B). Use the Export Raster World File tool to create the file from Raster A, then you can use it to update Raster B.
Here is the help article on world files, I hope this helps! http://desktop.arcgis.com/en/arcmap/10.3/manage-data/raster-and-images/world-files-for-raster-datasets.htm
If you have GDAL installed, you could use gdal_tranlate to assign a coordinate system to the raster using the known corner coordinates and the "-a_ullr" option.
Ex. (assign EPSG:2254 using corner coordinates):
gdal_translate original.tif -a_srs EPSG:2254 -a_ullr 964391.0 452402.0 1125431.0 294002.0 output.tif
You could get the corner coordinates from your example "A" file by using ArcGIS and viewing the "extents" information or by using "gdalinfo" and reading the "Corner Coordinates".