Arbitrary Number Of Transmit Antennas Research Articles

Single-RF and Twin-RF Spatial Modulation for an Arbitrary Number of Transmit Antennas

Spatial modulation (SM) constitutes an appealing low-complexity single radio frequency (RF) aided multiple-input multiple-output technique. Conventional SM schemes tend to rely on transmit antenna (TA) configurations, where the number of TAs is a power of two. In order to circumvent this limitation, a novel single RF-aided SM conceived for an arbitrary number of TAs (SM-ATA) is proposed, which is then further developed to a twin-RF enhanced SM-ATA (ESM-ATA) schedule for exploiting the diversity advantage of space-time block coding. Furthermore, low-complexity near-optimal detectors are designed for both the SM-ATA and ESM-ATA schemes. Our simulation results show that the proposed SM-ATA schemes offer almost the same performance as conventional SM systems, despite using a reduced number of TAs at the same transmission rate. The proposed twin-RF ESM-ATA schemes provide a beneficial performance gain over the existing twin-RF multiplexing based and space-time coding based SM schemes. Finally, an upper bound is derived for the average bit error probability, which is confirmed by our simulation results.

Information Guided Channel Hopping with an Arbitrary Number of Transmit Antennas

In order to realize the information guided channel hopping, also known as spatial modulation, with more design flexibility, in this paper we propose a novel scheme that allows operation with an arbitrary number of transmit antennas. Once the number of transmit antennas is not a power of two, the antennas' symbols are mapped by different numbers of bits. Subsequently, constellations with different orders are exploited for the modulation of radiated symbols so as to guarantee that the total number of bits transmitted at each time slot remains the same. Furthermore, we introduce a decoding algorithm with low complexity for this design. Numerical results on bit error rate performance are provided and substantiate that the proposed scheme turns out to be a promising alternative to the design of information guided channel hopping.

On the outage behavior of interference temperature limited CR-MISO channel

This paper investigates the outage behavior of peak interference power limited cognitive radio (CR) networks with multiple transmit antennas. In CR-multi-input single-output (MISO) channel, the total transmit power is distributed over the transmit- antennas. First, we use the orthogonal space-time codes (STC) to achieve the transmit diversity at CR-receiver (rx) and investigate the effect of the power distribution on the interference power received at the primary-receiver (P-rx). Then, we investigate the transmit antenna selection (TAS) scheme in which the CR system selects the best transmit antenna and allocates all the power to the selected best antenna. Two transmit antenna selection strategies are proposed depending on if feedback channel is available or not. We derive the closed form expressions of outage probability and outage capacity of all schemes with arbitrary number of transmit-antennas. We show that the proposed schemes significantly improve the outage capacity over the single antenna systems in Rayleigh fading environment. We also show that TAS based scheme outperforms the STC based scheme when peak interference power constraint is imposed on the P-rx only if a feedback channel from CR-rx to CR-transmitter is available.

Generally Explicit Space–Time Codes With Nonvanishing Determinants for Arbitrary Numbers of Transmit Antennas

Nonvanishing determinants have emerged as an attractive criterion enabling a space-time code achieve the optimal diversity-multiplexing gains tradeoff. It seems that cyclic division algebras play the most crucial role in designing a space-time code with nonvanishing determinants. In this paper, we explicitly construct space-time codes for arbitrary numbers of transmit antennas that achieve nonvanishing determinants and the optimal diversity-multiplexing gains tradeoff over Z [i]. Unlike previous methods usually arising a field compositum for two or more fields, our scheme, which only requires one simple extension, constitutes a much more efficient and feasible advancement whether in theory or practice.