| It is shown that a high density lattice sphere packing is a good mean to improve the performance of a frequency shift-keying modulation with correlated signals and noncoherent detection. It is proved that the pairwise error probability of the mul-tidimensional FSK alphabet is related to the lattice fundamental gain. A soft output noncoherent detector is described and used to estimate the perf...

|In this paper, we show that several coding schemes, and in particular turbo encoding , dramatically improve the performance of a noncoherently detected frequency shift-keying modulation with correlated signals. The APP decoding scheme based on bit-by-bit decisions proves to be better than a classical block decisions decoding scheme when the bit mapping is not optimized. Moreover, the choice of...

Let f1, . . . , fs be formal power series (respectively polynomials) in the variable x. We study the semigroup of orders of the formal series in the algebra KJf1, . . . , fsK ⊆ KJxK (respectively the semigroup of degrees of polynomials in K[f1, . . . , fs] ⊆ K[x]). We give procedures to compute these semigroups and several applications. We prove in particular that the space curve parametrized b...

In many communication system implementations, such as M-ary PSK and FSK modems, DMT for ADSL, as well as carrier and clock synchronization, the efficient conversion from rectangular to polar coordinates is essential. In this paper, we present a novel architecture for a circuit that computes the angle, as well as the magnitude, of a polar-form representation of a complex number, given the real a...

The performance of the mobile-to-mobile (M2M) network over keyhole Nakagami fading channels is investigated in this paper. Using the method of the probability density function (PDF) of the signal-to-noise ratio (SNR), the exact and approximate closed-form average symbol error probability (ASEP) expressions are derived for pulse-amplitude modulation (PAM), phase shift keying (PSK),and frequency ...

| Code division multiplexing or multiple access techniques provide a method of isolating multiuser transmissions in a non-orthogonal fashion. The communication resources are shared dynamically between users. In networks with bursty traac having a large numbers of subscribers, each having very low duty cycles, non-orthogonal channeliza-tion enables active users to exploit the shared portion of s...

Problem statement: Power consumption was one of the most challenging aspects to design low power wireless sensor nodes. The objectives of the study were to (i) Design low voltage, low power transmitters for wireless sensor nodes and (ii) Compare and analyze the performance of the transmitters. Approach: The transmitters employed direct digital modulation scheme to reduce the power consumption o...