The tradeoff of spectral efficiency (b/s/Hz) versus energy -per-information bit is the key measure of channel capacity in the wideband power-limited regime. This paper finds the fundamental bandwidth--power tradeoff of a general class of channels in the wideband regime characterized by low

period. We analyze the spectral efficiency (total capacity per chip) as a function of the number of users, spreading gain, and signal-to-noise ratio, and we quantify the loss in efficiency relative to an optimally chosen set of signature sequences and relative to multiaccess with no spreading. White

Spectral efficiency is a measure of the performance of channel coding methods. It refers to the ability of a given channel encoding method to utilize bandwidth efficiently. It is defined as the average number of bits per unit of time (bit rate) that can be transmitted per unit of bandwidth (bits

The spectral efficiency of large CDMA systems using higher order modulation schemes is investigated. Therefore, the asymptotic analysis for single cell systems and random spreading codes is used to obtain the signal-to-interference-andnoise ratio (SINR) after the Matched Filter (MF) and Linear

Abstract—We analyze the spectral efficiency (sum-rate per subcarrier) of randomly spread synchronous multicarrier code-division multiple access (MC-CDMA) subject to frequency-selective fading in the asymptotic regime of number of users and bandwidth going to infinity with a constant ratio. Both

The current emphasis on lightwave systems is on increasing the spectral efficiency of WDM systems. One of the techniques that is used for achieving high spectral efficiency in WDM systems is vestigial side band demultiplexing. This thesis reports the modeling and analysis of an experimental 40 Gbit

Abstract—We investigate the spectral efficiency of continuous phase modulations (CPMs). To this end, we need an effective bandwidth definition for a CPM signal, whose power spectral density has in principle an infinite support. The definition we adopt is based on the spacing between adjacent

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Recent results on the asymptotic empirical eigenvalue distribution of sum or product of matrices, based on the Free Probability Theory, have enabled the study of the asymptotic limits of Linear Precoded OFDM systems with MMSE equalization for ergodic and nonergodic channels. In this contribution, we extend these results to the MMSE Successive Interference Cancellation detector with realistic channels and give an explicit answer on the impact of the choice of certain type of spreading codes.

. It turns out that, although its simplicity, the proposed scheme showed very interesting features with respect to the spectral efficiency and the maximum number of possible pairwise cognitive communications. We impose the constraint that users successively transmit over available bands through selfish water