SINGLE CARRIER TRANSMISSION WITH ADAPTIVE ROLL-OFF FACTOR FOR ULTRA RELIABLE AND LOW LATENCY COMMUNICATION SYSTEMS

Abstract

A single carrier transmission that minimizes spectral efficiency loss and reduces out of band emission by using adaptive filtering in a block where different filter parameters are used for different symbols within a block.

Claims

1. A single carrier transmission that minimizes spectral efficiency loss and reduces out of band emission by using adaptive filtering in a block, formed of the following process steps: digitalizing an original information source if necessary in order to carry out encoding; coding the information source in order to compress a message that increases spectral efficiency of a communication system; filtering symbols by square root Raised Cosine (SRRC) filter having variable roll-off factors before transmission of the signal, in order to control and reduce out of band emission, using minimum roll-off factor of SRRC pulses, for the center symbols of a data block that has been transmitted in order to reduce out of band emission and to increase reliability by enabling minimum loss in spectral efficiency for URLLC; successively increasing the roll-off factor from the center pulses towards the edge pulses; using the maximum roll-off factor of the SRRC pulses for edge pulses as it affects the out of band emission more; passing the transmitted signal over a wireless channel with a limited band; adding the additive white Gaussian noise (AWGN), before reaching the receiver, to the signal that is transmitted which comprises a channel effect; the same SRRC filter and roll-off factor that is used in the transmitter in order to provide match-filtering is used by the receiver; and mapping the symbols to data bits.

Description

DESCRIPTION OF THE FIGURES

[0019] FIG. 1. Shows a classic single carrier transmission graph having a fixed roll-off factor

[0020] FIG. 2. Shows a single carrier transmission graph having an adaptive roll-off factor

[0021] FIG. 3. Shows a block diagram of a single carrier transmission

[0022] FIG. 4. Shows a spectrum graph for single-carrier transmission having a fixed roll-off factor and an adaptive roll-off factor

DESCRIPTION OF THE INVENTION

[0023] The single carrier transmission subject to the invention is formed of steps that minimizes spectral efficiency loss and reduces out of band emission by using adaptive filtering in a block. Different filter parameters for different symbols in a specific block are used in single carrier transmission.

[0024] These process steps have been illustrated in FIG. 3. The original information source herein can be digitalized if necessary as some messages need to be digital naturally, due to their structures. Said information source can be any type of data files such as a sound, music, picture or video file. The source-coding is used in order to compress the message that increases spectral efficiency of a communication system.

[0025] After the message information is prepared, the message is converted into symbols. Before transmitting the signal, the symbols are filtered by square root Raised Cosine (SRRC) filters in a transmitter.

[0026] The filtering process of the data information that has been transmitted is necessary in order to control or reduce out of band emission. As illustrated in FIG. 2, square root Raised Cosine (SRRC) pulses having variable roll-off factors are used in order to reduce out of band emission and increasing reliability to have minimum losses in spectral efficiency for URLLC.

[0027] The minimum roll-off factor is used for the center symbols for the transmitted data block and the roll-off factor is increased successively from the center pulses towards the edge pulses, cause more out of band emission. Due to this reason, the maximum roll-off factor is used for side pulses.

[0028] The signal that is transmitted travels over a wireless channel with a limited band. The additive white Gaussian noise (AWGN) is added before reaching the receiver, to the signal that is transmitted which comprises a channel effect.

[0029] The receiver uses the same SRRC filter and roll-off factor that is used in the transmitter. In this way, the overall filter is a Raised-Cosine filter.

[0030] The single carrier transmission is formed of the following process steps that minimizes spectral efficiency loss and reduces out of band emission by using adaptive filtering in a block; [0031] digitalizing the original information source if necessary in order to carry out the encoding, [0032] coding the information source in order to compress the message that increases spectral efficiency of a communication system, [0033] filtering the symbols by square root Raised Cosine (SRRC) filter having variable roll-off factors before the transmission of the signal, in order to control and reduce out of band emission, [0034] using the minimum roll-off factor, for the center symbols of a data block that has been transmitted in order to reduce out of band emission and to increase reliability by enabling minimum loss in spectral efficiency for URLLC. [0035] successively increasing the roll-off factor from the center pulses towards the edge pulses, [0036] using the maximum roll-off factor of the SRRC pulses for edge pulses as it affects the out of band emission more, [0037] passing the transmitted signal over a wireless channel with a limited band, [0038] adding the additive white Gaussian noise (AWGN), before reaching the receiver, to the signal that is transmitted which comprises a channel effect, [0039] the same SRRC filter and roll-off factor that is used in the transmitter in order to provide match-filtering is used by the receiver, [0040] mapping the symbols to data bits.

[0041] When the proposed single carrier transmission with an adaptive roll-off factor is compared with the classic single carrier transmission with a fixed roll-off factor, it can be seen that it provides reduced adjacent channel interference, lower latency and less occupied bandwidth, as shown in FIG. 4.

[0042] Applicability of single carrier with adaptive Raised Cosine filtering does not require any extra step compared with the conventional SC systems. It can easily be applied to industry by using similar methodology with the conventional systems.