Cooperative networking schemes provide spatial diversity gain (named cooperative diversity gain) using the antennas of spatially distributed users. Consistent research has been focusing on cooperative networks using orthogonal frequency division multiplexing (OFDM) and single carrier with frequency domain-equalization (SC-FDE). Coherent detection and frequency-domain equalization (FDE) require accurate channel estimation. In this paper, we present a performance comparison of cooperative OFDM relay network and cooperative SC-FDE relay network with pilot-assisted channel estimation. We consider a joint diversity combining and FDE in order to obtain a larger frequency diversity gain. When channel coding is used, cooperative OFDM relay network performs similarly to cooperative SC-FDE relay network in a frequency-selective fading channel.