In this paper we propose a slotted carrier sense multiple access with collision avoidance (CSMA/CA) DFT protocol with pulse signal transmission for integrated voice and data transmissions in WLAN systems. CSMA/CA protocol with pulse signal transmission enables a user having a packet ready to transmit initially some pulse signals with random intervals within a collision avoidance period before transmitting the packet to verify a clear channel. Priority can be given to voice calls by using larger pulse transmission probability. We develop an efficient analytical procedure to calculate channel utilization and packet delay performance of CSMA/CA DFT protocol in terms of the various packet generation rates, the lengths of collision avoidance period and packet transmission period, and pulse transmission probability. In the numerical results, we compared the average performance measures of CSMA/CA system with IFT protocol and showed that for voice traffic, network performance can be improved by the IFT protocol, but for higher traffic, network performance for data traffic can be improved by the DFT protocol.