Short-distance radio network data transmitting method

Abstract

The present invention relates to a short-range wireless network data transmitting method, belonging to the field of wireless communication technology. Said method includes the following steps: firstly, creating mapping list between bit sequence and band spread sequence; framing data sent from medium access control sulayer in network and searching band spread sequence correspondent to bit sequence in framed data packet from the above-mentioned mapping list between bit sequence and band spread sequence; pulse shaping said band spread sequence and obtaining baseband signal; modulating the baseband signal to in-phase and orthogonal carrier so as to obtain radio-frequency transmitting signal.

Description

technical field [0001] The invention relates to a short-range wireless network data sending method, which belongs to the technical field of wireless communication. Background technique [0002] In the application of short-range wireless network, in addition to its data rate and range, people also pay special attention to its power consumption, because most short-range wireless network devices are powered by batteries. The data transmission method determines the power efficiency, communication performance, and anti-interference ability of the system. The receiver design determines the receiver structure, algorithm complexity, and receiving performance. The two together determine the energy consumed by the system to transmit a bit. [0003] IEEE 802.15.4 is a short-range wireless network standard designed for low-speed, low-power consumption. It specifies the channel access mechanism - medium access control sublayer and data transmission method - physical layer, protocols of o...

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Problems solved by technology

[0010] The above-mentioned IEEE 802.15.4 standard 2.4G frequency band transmission method has considerable advantages in low-speed, low-power applications. Its disadvantages are, first, its spreading sequences are quasi-orthogonal Yes, the sidelobe and peak ratio of sequence cross-correlation can reach up to 0.25, which will increase the probability of wrong judgment during demodulation; second, it uses 32-bit chip sequence to represent 4 bits, plus half-sine shaping Pulse, the main lobe of the transmitted power spectrum reaches 3MHz at a data rate of 250Kb / s, and the spectral efficiency is only 0.083b / s / Hz; third, its preamble is composed of the first spreading sequence cycle repetition, but The autocorrelation characteristics of this sequence are not ideal. Although it is a 32-bit long sequence, its peak side lobe ratio is only 4, which is not conducive to the establishment of time synchronization; fourth, its preamble sequence is greatly affected by frequency offset. Large, when the frequency offset exceeds a certain value, the sliding correlation between the received signal and the local sequence may have no peak

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