Position Estimation in Corridors Along the Coupled Mode of Radiating Cables

Radiating cables are mostly used to provide radio communication in tunnels or corridors, but they can also be used to estimate the position of a mobile terminal along the cable. In this paper, a measuring receiver’s position was estimated by measuring the difference in the direct signal’s reception time, which was generated by a transmitter connected to one end of the radiating cable, and the delayed signal retransmitted from another end. During tests, a relatively narrowband (23 MHz) signal was used in the unlicensed band (2.4 GHz) and 50 m long coupled mode radiating cable. The cable was installed along a corridor in the office building. Measurement results used different equipment configurations (i.e., return signal only amplified or amplified and frequency-shifted), which presented possible sources of errors.

Optical Transmission of an Analog TV-Signal Coded at 2.24 GHz and Its Distribution by Using a Radiating Cable

In this work, an alternative technology to extend wireless coverage beyond the conventional methods of providing radio propagation coverage is presented. The use of a radiating cable is proposed for difficult-to-reach areas. In this regard, an indoor radiating cable is successfully employed for the distribution of an analog electric signal in a fiber-radio scheme using a microwave photonic filter. A filtered microwave band-pass window located at 2.24 GHz is used as an electrical carrier to transmit an analog TV-signal of 67.25 MHz over an optical link of 25.28 km. Measurements are carried out in an indoor environment. Experimental results demonstrate that the recovered signal is of good quality in each measurement location, exhibiting on average a signal-to-noise-ratio (SNR) of around 31.60 dB.

The Leaky Feeder, a Reliable Medium for Vehicle to Infrastructure Communications

Reliable vehicular communications is fast becoming a necessity. Vehicle to infrastructure (V2I) communication, which is critical for safety, is often interrupted when vehicles travel in tunnels. Leaky Feeder (LF) or radiating cable have been the primary solution to provide wireless access in tunnels and mines, but being overlooked until now. The LF is a natural multi antenna transceiver ideal for broadband short rage access. In this work, we model the LF as a linear antenna array and derive the average bit error rate (BER) in Rayleigh fading channel considering Quadrature Phase Shift Keying (QPSK) and M-Array Quadrature Amplitude (M-QAM) Modulations. We consider maximal ratio transmission (MRT) at the transmission end and coherent detection and maximal ratio combining (MRC) at the receiving end. Analytical expressions are derived for the BER. The effects of slot spacing and carrier frequency on the BER are also studied. Numerical evaluations show that the LF is a strong candidate for tunnels with much lower BER than a single antenna transmitter with the same SNR.