Accurate DS-CDMA packet-error rate analysis in Rayleigh fading

We present new packet-error rate (PER) analysis for both slotted and unslotted direct-sequence spread-spectrum packet communication systems in a slow Rayleigh fading environment. Based on the accurate improved Gaussian approximation, we derive closed-form expressions for the cumulative probability distribution function of the signal-to-interference-plus-noise ratio in binary phase-shift keying (PSK), quadratic PSK, and differential PSK-based code-division multiple-access (CDMA) systems having different types of chip waveforms including bandwidth-efficient waveforms. This leads to new accurate unified expressions for the PERs that account for bit-to-bit error dependence, which are valid for packets with unequal power levels. These new results facilitate accurate computation of the throughput performance of CDMA-based ALOHA local radio networks.