We propose, design, and prototype (using software defined radios) a layered hybrid decode-estimate- and-forward relaying strategy. The scheme relies on splitting the source message into two layers with unequal error protection (UEP). Considering half-duplex relay operation, cooperation takes place over two time-slots. The relay attempts to decode both layers during the first time-slot; with the probability of successfully decoding one of the layers being higher than the other due to UEP between the two layers. During the second time-slot, the relay transmits the jointly encoded message containing the successfully decoded layer(s) with the (imperfect) decoding estimates of the unrecoverable layer(s). In order to recover the source information, we design a decoding strategy at the destination that jointly operates on the signals received from the source and the relay. The proposed scheme is implemented using off-the-shelf systematic low-density parity-check codes, with joint decoding achieved through iterative message-passing. Simulations over narrowband Gaussian links indicate a performance gain of up to 3 dB compared to the unlayered operation at the source. We also present prototype results with over-the-air transmissions using National Instruments (NI) USRPs 2921s with all baseband processing implemented in NI LabView. These experimental results indicate significant performance gains over a conventional unlayered relaying approach.
Design and Experimental Prototyping of Layered Hybrid Decode-Estimate-Forward Relaying
2019-04-01
650016 byte
Conference paper
Electronic Resource
English