Orthogonal multi-carrier direct sequence code division multiple access (orthogonal MC DS-CDMA) is a combination of orthogonal frequency division multiplexing (OFDM) and time-domain spreading, while multi-carrier code division multiple access (MC-CDMA) is a combination of OFDM and frequency-domain spreading. In MC-CDMA, a good bit error rate (BER) performance can be achieved by using frequencydo...

In this paper, we have study the optimal design for synchronous wireless information and power transfer (SWIPT) in downlink multiuser orthogonal frequency division multiplexing (OFDM) systems, where the users gather energy and explain information by using the same type of signals received from a stable access point (AP). For the transmission of information, we have to consider two types of nume...

Recently, multi-carrier code division multiple access (MC-CDMA) has been attracting much attention for the broadband wireless access in the next generation mobile communications systems. In the case of uplink transmissions, the orthogonality property among users’ signals is lost since each user’s signal goes through different fading channel and hence, multi-access interference (MAI) is produced...

Modern wireless networks are faced with an increasing demand for higher data rates, better quality of service, and higher overall network capacities. In order to comply to these demands various limits, like the limited availability of the frequency spectrum and a complex space-time varying wireless environment must be overcome. Transmission schemes based on Multiple Input Multiple Output (MIMO)...

This paper is concerned with the bit-error rate (BER) performance of a cellular one-hop/symbol frequency-hopping multiple-access (FHMA) system operating through a multipath Rayleigh fading channel. -ary frequency shift keying modulation with noncoherent square-law envelope demodulation and Reed–Solomon (RS) coding is considered. The multiple-access and adjacent cell interference of the cellular...

We propose an orthogonal frequency division multiplexing frequency division multiple access (OFDMA) system with an adaptive multiple antenna transmission scheme for future wireless communkatlon systems. In the system, both a transmit diversity scheme with high order modulation and a spatial multiplexingscheme with low order modulation are employed for the given spectral efilciency, between whic...

In this article, a multiuser single carrier frequency division multiple access (SC-FDMA) system is considered, based on which an adaptive subcarrier and bit allocation algorithm is investigated. The algorithm has been used to achieve a subcarrier mapping mode in this system, which combines the advantages of singleand multi-carrier transmissions, such as, low peak to average power ratio, orthogo...

The adaptation of wireless technologies to the users rapidly changing demands is one of the main drivers of the wireless access systems development. New high-performance physical layer and multiple access technologies are needed to provide high speed data rates with flexible bandwidth allocation, hence high spectral efficiency as well as high adaptability. Multi carrier-code division multiple a...