10-04-2017, 08:32 PM
Abstract
In this paper, a secure voice communication system based on TMS320VC5410 is proposed, which includes the hardware design and the software design. Among them, the A/D and D/A conversions of voice signals are implemented by the MC145480, while data transmission is performed by the TL16C554. A chaotic voice encryption algorithm combining cat map and logistic map is implemented in this system. Experiments of both encrypted and non-encrypted voice communication over short distance have been performed, which demonstrates the feasibility of the proposed system.
This model shows part of a Bluetooth v1.0 system. Bluetooth is a short-range radio page link technology that operates in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band. The example modulates the signal using Gaussian frequency shift keying (GFSK) over a radio channel with maximum capacity of 1 Mbps.
The example uses frequency hopping over a 79 MHz frequency range to avoid interference with other devices transmitting in the band. In this scheme, the sender divides transmission time into 625-microsecond slots, and uses a new hop frequency for each slot. Although the data rate is only 1 Mbps, a much larger bandwidth of 79 MHz is required to simulate the frequency hopping effects.
Structure of the Example
The example contains the following elements:
Master transmitter
Radio channel
IEE 802.11b interferer
Slave receiver
Bit error rate (BER) display
Scopes