US 5,982,807 A · High data rate spread spectrum transceiver and associated methods

Abstract

A spread spectrum radio transceiver includes a high data rate baseband processor and a radio circuit connected thereto. The baseband processor preferably includes a modulator for spread spectrum phase shift keying (PSK) modulating information for transmission via the radio circuit. The modulator may include at least one modified Walsh code function encoder for encoding information according to a modified Walsh code for substantially reducing an average DC signal component to thereby enhance overall system performance when AC-coupling the received signal through at least one analog-to-digital converter to the demodulator. The demodulator is for spread spectrum PSK demodulating information received from the radio circuit. The modulator and demodulator are each preferably operable in one of a bi-phase PSK (BPSK) mode at a first data rate and a quadrature PSK (QPSK) mode at a second data rate. These formats may also be switched on-the-fly in the demodulator. Method aspects are also disclosed.

Claims61

Dependent claims

A spread spectrum radio transceiver comprising:

a baseband processor and a radio circuit connected thereto, said baseband processor comprising
a demodulator for spread spectrum phase shift keying (PSK) demodulating information received from said radio circuit,
at least one analog-to-digital (A/D) converter having an output connected to said demodulator and an input AC-coupled to said radio circuit,
said demodulator comprising at least one modified Walsh code function correlator for decoding information according to a modified Walsh code reducing an average DC signal component which in combination with the AC-coupling to said at least one A/D converter enhances overall performance, and
a modulator for spread spectrum PSK modulating information for transmission via the radio circuit, said modulator comprising at least one modified Walsh code function encoder for encoding information according to the modified Walsh code.

2 more elements

A baseband processor for a spread spectrum radio transceiver, said baseband processor comprising:

a modulator for spread spectrum phase shift keying (PSK) modulating information for transmission, said modulator comprising
at least one encoder for encoding information for transmission,
means for operating in one of a first format defined by bi-phase PSK (BPSK) modulation at a first data rate and a second format defined by quadrature PSK (QPSK) modulation at a second data rate,
header modulator means for modulating data packets to include a header at a third format defined by a predetermined modulation at a third data rate and variable data in one of the first and second formats;
and
a demodulator for spread spectrum PSK demodulating received information, said demodulator comprising
at least one correlator for decoding received information,
means for operating in one of the first and second formats,
header demodulator means for demodulating data packets by demodulating the header at the third format and for switching to the respective one of the first and second formats of the variable data after the header,
a first carrier tracking loop for the third format, and
a second carrier tracking loop for the first and second formats.

8 more elements

Dependencies are inferred from the claim text.

High data rate spread spectrum transceiver and associated methods

Life of this patent

High data rate spread spectrum transceiver and associated methods

Life of this patent

Abstract

Claims61