  In this paper, delay-free, low complexity, joint source-channel coding (JSCC)
for transmission of two correlated Gaussian memoryless sources over a Gaussian
Multiple Access Channel (GMAC) is considered. The main contributions of the
paper are two distributed JSCC schemes: one discrete scheme based on nested
scalar quantization, and one hybrid discrete-analog scheme based on a scalar
quantizer and a linear continuous mapping. The proposed schemes show promising
performance which improve with increasing correlation and are robust against
variations in noise level. Both schemes exhibit a constant gap to the
performance upper bound when the channel signal-to-noise ratio gets large.
