Exit Chart Aided Irregular Convolutional Code Design for Iterative Downlink SDMA Systems Using Imperfect Channel State Information

Abstract

We analyze a precoded and iteratively detected downlink multiuser system employing imperfect Spatio-Temporal Channel Impulse Response at the Transmitters (ST-CIRT) with the aid of Extrinsic Information Transfer (EXIT) charts. A Precoded Iterative DownLink Space Division Multiple Access (PI-DL-SDMA) system proposed in our previous research is further improved and shown to be capable of maintaining an infinitesimally low BER, despite using imperfect ST-CIRT. A further novel feature of the PI-DL-SDMA system is that we design an IrRegular Convolutional Code (IRCC) with the aid of EXIT chart analysis for creating an open EXIT tunnel between the inner decoder's and outer decoder's EXIT curve at a reduced E b /N 0 value and hence maintain an infinitesimally low BER.

Collaborative Transmission in Wireless Sensor Networks by a (1 + 1)-EA

“…In order to synchronise signals at the receiver, we propose the use of channel feedback as, for example, detailed in [45,28,44] to guide this synchronisation. The received sum-signal is analysed at the receiver and a feedback describing the state of the optimisation is created and transmitted back to the sensor nodes.…”

“…Solutions to providing receiver-based channel feedback are presented in [45,28,44]. The authors utilise long-term prediction at the transmitter in order to estimate the channel state evolution.…”