Title :
Optimal reception, performance bound, and cutoff rate analysis of references-assisted coherent CDMA communications with applications
Author_Institution :
Qualcomm Inc., San Diego, CA, USA
fDate :
10/1/1999 12:00:00 AM
Abstract :
Coherent spread-spectrum communications with transmitted reference-based, also called pilot-based, channel estimation is considered for code-division multiple-access (CDMA) communications over fading channels. Both noncontiguous time-division multiplexed reference symbol-based and continuous code-division multiplexed channel-based schemes are described. Assuming mean square error or optimal robust channel estimation, we derive the optimal receiver structure with a maximum-likelihood convolutional decoder. In addition, the Bhattacharyya bound and the cutoff rate of the reference-assisted coherent communications are derived. These analytical results are used for evaluating system performance and for selecting parameters such as coding rate and the data to reference power ratio to optimize system performance. Simulation results are given showing that the reverse link performance in a CDMA system can be significantly improved by using the reference-assisted coherent communication instead of noncoherent reception of orthogonally coded signal
Keywords :
cellular radio; code division multiple access; convolutional codes; fading channels; maximum likelihood decoding; mean square error methods; multiuser channels; parameter estimation; radio links; radio receivers; spread spectrum communication; time division multiplexing; Bhattacharyya bound; cellular communications; code-division multiple-access; coding rate; coherent spread-spectrum communications; continuous code-division multiplexed channel; cutoff rate; cutoff rate analysis; data to reference power ratio; fading channels; maximum-likelihood convolutional decoder; mean square error; noncoherent reception; noncontiguous TDM reference symbol; optimal receiver structure; optimal reception; optimal robust channel estimation; orthogonally coded signal; performance bound; pilot-based channel estimation; reference-based channel estimation; references-assisted coherent CDMA communications; reverse link performance; simulation results; system performance; time-division multiplexing; Channel estimation; Code division multiplexing; Fading; Maximum likelihood estimation; Mean square error methods; Multiaccess communication; Performance analysis; Robustness; Spread spectrum communication; System performance;
Journal_Title :
Communications, IEEE Transactions on
