Wide-band frequency  Transmission Network Technology is an innovative technology using one Wide-band frequency  transmitter to achieve multi-channel transmitting, solving the existing problems of single-channel system in one fell swoop. It is conducive to build up the terrestrial digital tv multi-channel single frequency network with effective coverage and strong stability.

Wide-band frequency  transmission network technology has been successfully applied in China, its advent lies in:

1). The signal using the low power multiplex approach before delivered to transmitter, it can generate a number of adjacent frequency (or repeat frequency) RF signals. In the multi-channel single frequency networking stage, the entire network can share the same exciter, so that the system RF signal can reach to a high level of consistency, without the excursion of frequency, phase, level, etc. it is conducive to build the multi-channel single frequency network.

2). With the highly coherent RF signal source, conducive to the full play of Wide-band frequency  RF delay technology, it brings the new model of single frequency networking.

3). Wide-band frequency  networking technology solution can save the cost of multiplexer, increase the efficiency and quality of multiple frequency synthesis.

4). Cast aside the power combiner of the traditional transmitting system, dramatically reduce the insertion loss in system connection, it can significantly reduce the transmission power meantime ensuring the equal coverage effect. Saving the investment and operating cost, it is conducive to the industry healthy development.

5). Thoroughly avoid the signal interference between channels caused by the frequency shift between spectrum when the multi-channel high-power combiner output.

6). Wide-band frequency  transmission network technology using Wide-band frequency  radio frequency transmitting, it makes multipoint low-power distribution coverage as possible, making the large-scale networking coverage becomes more stable, reliable and easy to maintain.

CEKE DTMB Wide-band frequency  Solution Main Features

I.   Wide-band frequency  transmitting

One digital Wide-band frequency  transmitter can transmit 2 to 10 adjacent channels of the UHF frequency, it can replace the several transmitters of single-channel system, abandoned power synthesizer, greatly improve the transmitting efficiency. This brings many benefits for the system construction.

1)using the more smaller transmitting power to achieve same coverage effect;

2)saving the investment of the transmission system, saving the investment for station supporting resources input;

3)saving the operating cost(electricity and maintenance costs);

4)To reduce the electromagnetic pollution.

II. Adjacent channel application

Frequency resources are non-renewable natural resources. Along with social progress, the frequency resources became increasingly scarce and valuable. The traditional transmission system used the across-frequency transmission technology, means half of the frequency resources was wasted. Meantime, since the usage of power combiner, it is not conducive to use the adjacent frequency channels and also not conducive to flexibly adjust transmission frequency points coordinated with the network optimization.

Our company’s adjacent channel transmission solution, can perfectly use the adjacent frequency, increase the utilization rate of frequency, conducive to frequency planning and frequency adjustment.                        

III. Large area coverage with a small power

Traditional transmission system exists two major technical flaws: big noise(15dB), poor frequency accuracy(1×10-6). Therefore, the single-channel transmission power is relatively large, easily reach 1kw, in order to meet the coverage requirements.

Our system is low noise(2~6dB), phase noise: -110dBc/10KHz, high frequency accuracy(1×10-9),no power combiner insertion loss, combined with the latest technological achievements of DTMB network(C=1) single-carrier technology mode, takes the technological advantages of low carrier PAPR, high receiver sensitivity, receiving adaptive equalization algorithm, etc. Therefore, single-channel 50W power can achieve traditional 400W power coverage effect.

IV. Realize network stations long distance setup

The System is DTMB network(C=1) single-carrier technology mode networking. GB(national standard) single-carrier technology mode receiver using the adaptive equalizer to counter the various channel fading, broke through the technical difficulties that the single-carrier multi-path resistance to 0dB, and solve the high-speed mobile reception problem. This means the single frequency network stations distance can be more than 60 km away. This system can adapt to the existing analogue television network transmission station to achieve the large-area fixed receiving coverage.