In most commercial wideband code division multiple access systems, the transmitted signal in the downlink channel is spread by orthogonal codes to accommodate different users. However, frequency selective fading destroys the orthogonality and causes multiple access interference. Application of a chip level decision feedback equaliser with the Alamouti transmit diversity scheme is proposed to re...

The paper describes an adaptive algorithm for power and bit allocations in a multiple user Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO OFDM) system with Space Division Multiple Access, which operates in a frequency selective fading channel. The zero forcing (ZF) technique is applied to accomplish multi user detection (MUD). A Lagrange multiplier method is app...

The use of time-frequency distributions is proposed as a nonlinear signal processing technique that is combined with a pattern recognition approach to identify superimposed transmission modes in a reconfigurable wireless terminal based on softwaredefined radio techniques. In particular, a software-defined radio receiver is described aiming at the identification of two coexistent communication m...

Here we continue the analytic study of packet switching in radio channels which we reported upon in our two previous papers [ 11, [2]. Again we consider a population of terminals communicating with a central station over a packet-switched radio channel. The allocation of bandwidth among the contending terminals can befixed [e.g., time-division multiple access (TDMA) or frequency-division multip...

3rd generation partnership project (3GPP) long term evolution (LTE) uses single carrier-frequency division multiple access (SC-FDMA) in uplink transmission and orthogonal frequency division multiple access (OFDMA) scheme for the downlink. One of the most important challenges for a transceiver design is channel estimation (CE) and equalization. In this paper, a training based least mean square (...

Orthogonal Frequency-Division Multiple Access (OFDMA) is a multi-user version of the Orthogonal frequency-division multiplexing (OFDM). OFDMA is used in the mobility mode of IEEE 802.16 WirelessMAN Air Interface standard, commonly referred to as WiMAX. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users [1], [2]. The performance of these systems depend o...

Orthogonal Frequency-Division Multiple Access (OFDMA) is a multi-user version of the Orthogonal frequency-division multiplexing (OFDM). OFDMA is used in the mobility mode of IEEE 802.16 WirelessMAN Air Interface standard, commonly referred to as WiMAX. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users [1], [2]. The performance of these systems depend o...

Orthogonal Frequency Division Multiple Access (OFDMA) has recently been applied widely in wireless communication systems due to its high data rate transmission capability with high bandwidth efficiency and its robustness to multi-path fading. But it has several inherent disadvantages such as the large PAPR and the sensitivity to Carrier Frequency Offset (CFO).Hence much attention has been focus...

Power control in cellular systems is applied to numerous communication architectures. For Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) power control reduces intercell interference and improves capacity. For Code Division Multiple Access (CDMA) power control is a required part of the base station and mobile station designs. Power Control reduces interference...