Coherent multicode ds-cdma mobile radio access

The reverse link performance of coherent multicode DS-CDMA [4], [5] under multipath Rayleigh fading environments is evaluated by computer simulation. It is demonstrated that the combined use of pilot symbol assisted (PSA)coherent RAKE, channel coding, antenna diversity, and transmit power control is powerful in lowering the required signal energy per information bit-to-interference plus additive white Gaussian nose (AWGN) power spectrum density ratio (E_b/I₀) which is an important parameter in determining the link capacity. It is also demonstrated that with slight performance degradation, high rate data transmission is realized by using multiple orthogonal spreading codes in parallel (orthogonal multicode transmission). Based on the simulated link performance, the reverse link cell capacity and link budget are also evaluated. It is found that parameter η = I₀/N₀ plays an important role in controlling the cell capacity and the maximum allowable path loss, where N₀ is the AWGN power spectrum density. DS-CDMA, mobile raido access, cellular system.