The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, we consider the half-duplex cooperative multiple-access channel (CMAC) in block-fading channels. Each link employs orthogonal frequency division multiplexing (OFDM) which is suitable for high rate wideband transmission and the modulated symbols are drawn from a finite constellation set. We first obtain the diversity order of the CMAC, as a function of the time sharing variables of the...
In this paper, we consider the half-duplex cooperative multiple-access channel (CMAC). We seek to design multiple turbo codes to minimize the information outage in the block fading channel. Since we consider an outage to occur even if the message of one of the sources fails to be decoded successfully, we employ a joint network-channel coding approach in our design. The codes are optimized using the...
In a previous work by Wu et ah, it is shown that the performance of the pre-transformed space-time block coded orthogonal frequency division multiplexing (PT-STBC-OFDM) system has much superior performance compared to the normal STBC-OFDM system. In this paper, we present an analytical study on the bit error rate (BER) of the PT-STBC-OFDM system. We derive the noise distribution of PT-STBC-OFDM system...
We introduce the multiple access relay channel with generalized feedback (MARC-GF), which is more general than the known MARC (without feedback) and MAC-GF (without relay). In the MARC-GF, two sources, assisted by a common relay, send independent messages to a destination. The sources and relay each receives some feedback that may facilitate this communication. We propose and analyze a decode-and-forward...
We compare four open-loop transmit diversity schemes in a coded Orthogonal Frequency Division Multiplexing (OFDM) system with four transmit antennas, namely cyclic delay diversity (CDD), Space-Time Block Code (STBC, Alamouti code is used) with CDD, Quasi-Orthogonal STBC (QO-STBC) and Minimum- Decoding-Complexity QOSTBC (MDC-QOSTBQ. We show that in a coded system with low code rate, a scheme with spatial...
In this paper, we study the performance of two transmit diversity schemes, the cyclic delay diversity (CDD) and the groupwise space time block code (G-STBC), for high throughput wireless local area network (LAN) system using orthogonal frequency division multiplexing (OFDM) and multiple input multiple output (MIMO) technologies. We compare the performance of CDD and the G-STBC transmission with the...
We study space-time precoding techniques for asymmetric multiple-input multiple-output (MIMO) channels with more transmit than receive antennas which is a typical downlink setup. Under the condition that channel state information (CSI) is perfectly known at the receiver, but not known at the transmitter, we consider groupwise space-time block coding (GSTBC), quasi-orthogonal space-time block coding...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.