Coding vs. spreading over block fading channels

Biglieri, Ezio;Caire, Giuseppe;Taricco, Giorgio
Book chapter in "Spread Spectrum: Developments for the New Millenium", Francis Swarts (Ed.), Boston, MA: Kluwer Academic Publishers

In this chapter we study the optimum tradeoff coding vs. spreading in a single-cell CDMA mobile communication system with block-fading, block-synchronous (but symbol-asynchronous) transmission, and slow power control. The optimization criterion we choose is based on system capacity, as measured in users/cell X bit/s/Hz,
We adopt an information-theoretic definition of outage: this is the event that the mutual information experienced by a user code word falls below the actual user code rate. The system capacity is then defined as above under decoding-delay and outage-probability constraints. We examine the conventional single- user receiver and a linear MMSE multiuser receiver. Our results show that, with ideal power control and optimum coding/spreading tradeoff, capacities close to 1 user/cell X bit/s/Hz are achievable by the conventional receiver, while the capacity gain offered by MMSE multiuser detection is moderate. With non-ideal power control MMSE multiuser detection is more attractive: in fact, it proves to be very robust to residual power-control errors, while conventional detection suffers from a large capacity degradation.


Type:
Book
Date:
1998-10-01
Department:
Communication systems
Eurecom Ref:
321
Copyright:
© Springer. Personal use of this material is permitted. The definitive version of this paper was published in Book chapter in "Spread Spectrum: Developments for the New Millenium", Francis Swarts (Ed.), Boston, MA: Kluwer Academic Publishers and is available at :

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