Transmission of CDMA signals over an analog optical link

A transmission system for carrying CDMA signals between a centralized base station of a wireless communication system and a remote antenna unit, comprising:

• an optical fiber connecting the base station and the remote antenna unit;
• a downlink laser transmitter in the base station coupled to the fiber for transmitting CDMA signals at an optical wavelength;
• a downlink optical receiver in the remote antenna unit coupled to the fiber for receiving CDMA signals at the optical wavelength;
• an uplink laser transmitter in the remote antenna unit coupled to the fiber for transmitting CDMA signals at the optical wavelength;
• and
• an uplink optical receiver in the base station coupled to the fiber for receiving CDMA signals at the optical wavelength;
• wherein the RF drive current driving each of the uplink and downlink laser transmitters is maintained above a level;
• wherein the dynamic range of the transmission system exceeds 36 dB on the unlink from the remote antenna unit to the base station, and exceeds 26 dB on the downlink from the base station to the remote antenna unit.

A transmission system for carrying CDMA signals between a centralized base station of a wireless communication system and a remote antenna unit, comprising:

• an optical fiber connecting the base station and the remote antenna unit;
• a downlink laser transmitter in the base station coupled to the fiber for transmitting CDMA signals at an optical wavelength;
• a downlink optical receiver in the remote antenna unit coupled to the fiber for receiving CDMA signals at the optical wavelength;
• an uplink laser transmitter in the remote antenna unit coupled to the fiber for transmitting CDMA signals at the optical wavelength;
• and
• an uplink optical receiver in the base station coupled to the fiber for receiving CDMA signals at the optical wavelength;
• wherein
• the RF drive current driving each of the uplink and downlink laser transmitters is maintained above a level, wherein:
• one of the uplink and downlink laser transmitters is a Fabry-Perot laser, and
• the other one of the uplink and downlink laser transmitters is a single-frequency laser which has a different emission wavelength than the Fabry-Perot laser;
• wherein the dynamic range of the transmission system exceeds 36 dB on the uplink from the remote antenna unit to the base station, and exceeds 26 dB on the downlink from the base station to the remote antenna unit.

A transmission system for carrying CDMA signals between a centralized base station of a wireless communication system and a remote antenna unit, comprising:

• an optical fiber connecting the base station and the remote antenna unit;
• a downlink laser transmitter in the base station coupled to the fiber for transmitting CDMA signals at an optical wavelength;
• a downlink optical receiver in the remote antenna unit coupled to the fiber for receiving CDMA signals at the optical wavelength;
• an uplink laser transmitter in the remote antenna unit coupled to the fiber for transmitting CDMA signals at the optical wavelength;
• and
• an uplink optical receiver in the base station coupled to the fiber for receiving CDMA signals at the optical wavelength;
• wherein
• the RF drive current driving each of the uplink and downlink laser transmitters is maintained above a level, wherein:
• the dynamic range of the uplink from the remote antenna unit to the base station exceeds the dynamic range of the downlink from the base station to the remote antenna unit;
• wherein the dynamic range of the transmission system exceeds 36 dB on the uplink from the remote antenna unit to the base station, and exceeds 26 dB on the downlink from the base station to the remote antenna unit.